foramina of the base of the skull - 1 file download

Question 1 of 560

Which of the following structures is not transmitted by the jugular foramen?

Hypoglossal nerve

Accessory nerve

Internal jugular vein

Inferior petrosal sinus

Vagus nerve

Contents of the jugular foramen: Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries

Theme from 2009 exam The jugular foramen may be divided into three compartments:

Anterior compartment transmits the inferior petrosal sinus

Middle compartment transmits cranial nerves IX, X and XI Posterior compartment transmits the sigmoid sinus

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Foramina of the base of the skull

Foramen Location Contents

http://emrcs.com/question/question.php?q=0#left-panel


Foramen ovale Sphenoid

bone

Otic ganglion

V3 (Mandibular nerve:3rd branch of

trigeminal)

Accessory meningeal artery

Lesser petrosal nerve

Emissary veins

Foramen spinosum Sphenoid bone

Middle meningeal artery Meningeal branch of the Mandibular nerve

Foramen rotundum Sphenoid

bone

Maxillary nerve (V2)

Foramen lacerum/ carotid canal

Sphenoid bone

Base of the medial pterygoid plate.

Internal carotid artery*

Nerve and artery of the pterygoid canal

Jugular foramen Temporal

bone

Anterior: inferior petrosal sinus

Intermediate: glossopharyngeal, vagus, and accessory nerves.

Posterior: sigmoid sinus (becoming the internal jugular vein)

and some meningeal branches from the occipital and ascending pharyngeal arteries.

Foramen magnum Occipital

bone

Anterior and posterior spinal arteries

Vertebral arteries Medulla oblongata

Stylomastoid

foramen

Temporal

bone

Stylomastoid artery

Facial nerve

Superior orbital fissure

Sphenoid bone

Oculomotor nerve (III)

Recurrent meningeal artery

Trochlear nerve (IV)

Lacrimal, frontal and nasociliary branches of ophthalmic

nerve (V1)


Abducent nerve (VI)

Superior ophthalmic vein

*= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum. Base of skull anatomical overview

Image sourced from Wikipedia

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http://en.wikipedia.org/wiki/Foramina%20of%20the%20skull

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Question 2 of 560

A 19 year old female is admitted with suspected meningitis. The House Officer is due to perform a lumbar puncture. What is the most likely structure first encountered when the needle is inserted?

Ligamentum flavum

Denticulate ligament

Dural sheath

Pia Mater

Supraspinous ligament

Theme from September 2012 exam Please rate this question:


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Lumbar puncture

Lumbar punctures are performed to obtain cerebrospinal fluid. In adults, the procedure is best performed at the level of L3/L4 or L4/5 interspace. These regions are below the termination of the spinal cord at L1. During the procedure the needle passes through:

The supraspinous ligament which connects the tips of spinous processes and the interspinous ligaments between adjacent borders of spinous processes

Then the needle passes through the ligamentum flavum, which may cause a give as it is penetrated

A second give represents penetration of the needle through the dura mater into the subarachnoid space. Clear CSF should be obtained at this point

References

Boon et al Lumbar Puncture: Anatomical Review of a Clinical Skill. Clinical Anatomy 17:544553 (2004)


Question 3 of 560

A 45 year old motor cyclist sustains a tibial fracture and is noted to have anaesthesia of the web space between his first and second toes. Which of the nerves listed below is most likely to be compromised?

Superficial peroneal nerve

Deep peroneal nerve

Sural nerve

Long saphenous nerve

Tibial nerve

Theme from September 2014 Exam The deep peroneal nerve lies in the anterior muscular compartment of the lower leg and can be compromised by compartment syndrome affecting this area. It provides cutaneous sensation to the first web space. The superficial peroneal nerve provides more lateral cutaneous innervation. Please rate this question:


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Deep peroneal nerve

Origin From the common peroneal nerve, at the lateral aspect of the fibula, deep to

peroneus longus

Nerve root values L4, L5, S1, S2

Course and

relation

Pierces the anterior intermuscular septum to enter the anterior

compartment of the lower leg

Passes anteriorly down to the ankle joint, midway between the two


malleoli

Terminates In the dorsum of the foot

Muscles

innervated

Tibialis anterior

Extensor hallucis longus

Extensor digitorum longus

Peroneus tertius

Extensor digitorum brevis

Cutaneous

innervation

Web space of the first and second toes

Actions Dorsiflexion of ankle joint

Extension of all toes (extensor hallucis longus and extensor

digitorum longus)

Inversion of the foot

After its bifurcation past the ankle joint, the lateral branch of the deep peroneal nerve innervates the extensor digitorum brevis and the extensor hallucis brevis The medial branch supplies the web space between the first and second digits.

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Question 4 of 560

A patient undergoes a femoral hernia repair and at operation the surgeon decides to enter the

abdominal cavity to resect small bowel. She makes a transverse incision two thirds of the way

between umbilicus and the symphysis pubis. Which of the structures listed below will not be divided?

Rectus abdominis

External oblique aponeurosis

Peritoneum

Fascia transversalis

Posterior lamina of the rectus sheath

An incision at this level lies below the arcuate line and the posterior wall of the rectus sheath is

deficient at this level.



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Rectus abdominis muscle

The rectus sheath is formed by the aponeuroses of the lateral abdominal wall muscles. The rectus

sheath has a composition that varies according to anatomical level.

1. Above the costal margin the anterior sheath is composed of external oblique aponeurosis, the

costal cartilages are posterior to it.

2. From the costal margin to the arcuate line, the anterior rectus sheath is composed of external

oblique aponeurosis and the anterior part of the internal oblique aponeurosis. The posterior part of


the internal oblique aponeurosis and transversus abdominis form the posterior rectus sheath.

3. Below the arcuate line the aponeuroses of all the abdominal muscles lie in anterior aspect of the

rectus sheath. Posteriorly lies the transversalis fascia and peritoneum.

The arcuate line is the point at which the inferior epigastric vessels enter the rectus sheath.

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Question 5 of 560

What is the lymphatic drainage of the ovaries?

Internal iliac nodes

Common iliac nodes

Para-aortic nodes

Para uterine nodes

Inguinal nodes

Theme from September 2015 Exam The lymphatic drainage of the ovary follows the gonadal vessels and drainage is therefore to the para-aortic nodes. Please rate this question:


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Lymphatic drainage of the ovaries, uterus and cervix

The ovaries drain to the para-aortic lymphatics via the gonadal vessels.

The uterine fundus has a lymphatic drainage that runs with the ovarian vessels and may thus drain to the para-aortic nodes. Some drainage may also pass along the round ligament to the inguinal nodes.

The body of the uterus drains through lymphatics contained within the broad ligament to the iliac lymph nodes.

The cervix drains into three potential nodal stations; laterally through the broad ligament to the external iliac nodes, along the lymphatics of the uterosacral fold to the presacral nodes and posterolaterally along lymphatics lying alongside the uterine vessels to the internal iliac nodes.

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Question 6-8 of 560

Theme: Axillary anatomy

A. Medial pectoral nerve

B. Thoracodorsal nerve

C. Lateral pectoral nerve

D. Intercostobrachial nerve

E. Medial cord of the brachial plexus

F. Long thoracic nerve

G. Axillary nerve

H. Accessory nerve

Please identify the structure that is most likely to be affected in the scenarios described below. Each

structure may be used once, more than once or not at all.

6. A 44 year old lady has undergone a mastectomy and axillary node clearance. Post operatively, she

notices a patch of anaesthesia of her axillary skin when she applies an underarm deodorant.

You answered Medial pectoral nerve

The correct answer is Intercostobrachial nerve

The intercostobrachial nerves traverse the axilla and innervate the overlying skin. These can be

injured or divided during axillary surgery and the result is anaesthesia of the overlying skin.

7. A 44 year old lady has undergone a mastectomy and axillary node clearance to treat breast cancer.

Post operatively, it is noted that she has winging of the scapula.


The correct answer is Long thoracic nerve

Injury to the long thoracic nerve (which innervates the serratus anterior) can occur as it lies at the

medial aspect of the axilla, winging of the scapula will then result.

8. A 44 year old lady who works as an interior decorator has undergone a mastectomy and axillary

node clearance to treat breast cancer. Post operatively, she comments that her arm easily

becomes fatigued when she is painting walls.


The correct answer is Thoracodorsal nerve

The most likely explanation for this is that the thoracodorsal nerve has been injured. This will result

in atrophy of latissimus dorsi and this will become evident with repetitive arm movements where

the arm is elevated and moving up and down (such as in painting). Injury to the pectoral nerves

may produce a similar picture but this pattern of injury is very rare and the pectoral nerves are

seldom injured in breast surgery.



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Axilla

Boundaries of the axilla

Medially Chest wall and Serratus anterior

Laterally Humeral head


Floor Subscapularis

Anterior aspect Lateral border of Pectoralis major

Fascia Clavipectoral fascia

Content:

Long thoracic nerve (of

Bell)

Derived from C5-C7 and passes behind the brachial plexus to enter the axilla.

It lies on the medial chest wall and supplies serratus anterior. Its location

puts it at risk during axillary surgery and damage will lead to winging of the

scapula.

Thoracodorsal nerve and

thoracodorsal trunk

Innervate and vascularise latissimus dorsi.

Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein.

Becomes the subclavian vein at the outer border of the first rib.

Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary

surgery. They provide cutaneous sensation to the axillary skin.

Lymph nodes The axilla is the main site of lymphatic drainage for the breast.

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Question 9 of 560

A 35 year old farm labourer injures the posterior aspect of his hand with a mechanical scythe. He severs some of his extensor tendons in this injury. How many tunnels lie in the extensor retinaculum that transmit the tendons of the extensor muscles?

One

Three

Four

Five

Six

There are six tunnels, each lined by its own synovial sheath. Please rate this question:


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Extensor retinaculum

The extensor rentinaculum is a thickening of the deep fascia that stretches across the back of the wrist and holds the long extensor tendons in position. Its attachments are:

The pisiform and triquetral medially The end of the radius laterally

Structures related to the extensor retinaculum

Structures superficial to the

retinaculum

Basilic vein

Dorsal cutaneous branch of the ulnar nerve

Cephalic vein

Superficial branch of the radial nerve


Structures passing deep to the

extensor retinaculum

Extensor carpi ulnaris tendon

Extensor digiti minimi tendon

Extensor digitorum and extensor indicis tendon

Extensor pollicis longus tendon

Extensor carpi radialis longus tendon

Extensor carpi radialis brevis tendon

Abductor pollicis longus and extensor pollicis

brevis tendons

Beneath the extensor retinaculum fibrous septa form six compartments that contain the extensor muscle tendons. Each compartment has its own synovial sheath. The radial artery The radial artery passes between the lateral collateral ligament of the wrist joint and the tendons of the abductor pollicis longus and extensor pollicis brevis. Image illustrating the topography of tendons passing under the extensor retinaculum


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Question 10 of 560

http://en.wikipedia.org/wiki/Extensor%20retinaculum%20of%20the%20hand

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A 23 year old man undergoes an orchidectomy. The right testicular vein is ligated; into which structure does it drain?

Right renal vein

Inferior vena cava

Common iliac vein

Internal iliac vein

External iliac vein

Theme from April 2012 exam Theme from April 2014 exam The testicular venous drainage begins in the septa and these veins together with those of the tunica vasculosa converge on the posterior border of the testis as the pampiniform plexus. The pampiniform plexus drains to the testicular vein. The left testicular vein drains into the left renal vein. The right testicular vein drains into the inferior vena cava. Please rate this question:


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Scrotal and testicular anatomy

Spermatic cord

Formed by the vas deferens and is covered by the following structures:

Layer Origin

Internal spermatic fascia Transversalis fascia

Cremasteric fascia From the fascial coverings of internal oblique


Layer Origin

External spermatic fascia External oblique aponeurosis

Contents of the cord

Vas deferens Transmits sperm and accessory gland secretions

Testicular artery Branch of abdominal aorta supplies testis and

epididymis

Artery of vas deferens Arises from inferior vesical artery

Cremasteric artery Arises from inferior epigastric artery

Pampiniform plexus Venous plexus, drains into right or left testicular vein

Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the

vas

Genital branch of the genitofemoral

nerve

Supplies cremaster

Lymphatic vessels Drain to lumbar and para-aortic nodes

Scrotum

Composed of skin and closely attached dartos fascia.

Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer

Testes

The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia.

The testicular arteries arise from the aorta immediately inferiorly to the renal arteries.

The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava.

Lymphatic drainage is to the para-aortic nodes.

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Question 11 of 560

A 44 year old lady is undergoing an abdominal hysterectomy and the ureter is identified during the ligation of the uterine artery. At which site does it insert into the bladder?

Posterior

Apex

Anterior

Base

Superior aspect of the lateral side

Theme from September 2012 Exam The ureters enter the bladder at the upper lateral aspect of the base of the bladder. They are about 5cm apart from each other in the empty bladder. Internally this aspect is contained within the bladder trigone. Please rate this question:


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Ureter

25-35 cm long Muscular tube lined by transitional epithelium Surrounded by thick muscular coat. Becomes 3 muscular layers as it crosses the bony pelvis

Retroperitoneal structure overlying transverse processes L2-L5 Lies anterior to bifurcation of iliac vessels Blood supply is segmental; renal artery, aortic branches, gonadal branches, common iliac

and internal iliac Lies beneath the uterine artery

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Question 12 of 560

What is the correct embryological origin of the stapes?

First pharyngeal arch

Second pharyngeal arch

Third pharyngeal arch

Fourth pharyngeal arch

Fifth pharyngeal arch

Embryological origin stapes = 2nd pharyngeal arch

The ectoderm covering the outer aspect of the second arch originates from a strip of ectoderm

lateral to the metencephalic neural fold. The cartilaginous element to this, eponymously known as

Reicherts cartilage extends from the otic capsule to the midline on each side. Its dorsal end

separates and becomes enclosed in the tympanic cavity as the stapes.

Theme from September 2013 exam

Theme from April 2012 Exam

The dorsal ends of the cartilages of the first and second pharyngeal arches articulate superior to the

tubotympanic recess. These cartilages form the malleus, incus and stapes. At least part of the

malleus is formed from the first arch and the stapes from the second arch. The incus is most likely to

arise from the first arch.



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Pharyngeal arches


These develop during the fourth week of embryonic growth from a series of mesodermal

outpouchings of the developing pharynx.

They develop and fuse in the ventral midline. Pharyngeal pouches form on the endodermal side

between the arches.

There are 6 pharyngeal arches, the fifth does not contribute any useful structures and often fuses

with the sixth arch.

Pharyngeal arches

Pharyngeal

arch

Muscular

contributions

Skeletal

contributions Endocrine Artery Nerve

First Muscles of

mastication

Anterior belly of

digastric

Mylohyoid

Tensor tympanic

Tensor veli palatini

Maxilla

Meckels

cartilage

Incus

Malleus

n/a Maxillary

External

carotid

Mandibular

Second Buccinator

Platysma

Muscles of facial

expression

Stylohyoid

Posterior belly of

digastric

Stapedius

Stapes

Styloid process

Lesser horn

and upper

body of hyoid

n/a Inferior

branch of

superior

thyroid artery

Stapedial

artery

Facial

Third Stylopharyngeus Greater horn

and lower part

of hyoid

Thymus

Inferior

parathyroids

Common and

internal

carotid

Glossopharyngeal

Fourth Cricothyroid

All intrinsic

muscles of the soft

palate

Thyroid and

epiglottic

cartilages

Superior

parathyroids

Right-

subclavian

artery, Left-

aortic arch

Vagus

Pharyngeal

arch

Muscular

contributions

Skeletal

contributions Endocrine Artery Nerve

Sixth All intrinsic

muscles of the

larynx (except

cricothyroid)

Cricoid,

arytenoid and

corniculate

cartilages

n/a Right -

Pulmonary

artery, Left-

Pulmonary

artery and

ductus

arteriosus

Vagus and

recurrent

laryngeal nerve

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Question 13 of 560

A 20 year old lady presents with pain on the medial aspect of her thigh. Investigations show a large ovarian cyst. Compression of which of the nerves listed below is the most likely underlying cause?

Sciatic

Genitofemoral

Obturator

Ilioinguinal

Femoral cutaneous

Theme from April 2012 Exam The cutaneous branch of the obturator nerve is frequently absent. However, the obturator nerve is a recognised contributor to innervation of the medial thigh and large pelvic tumours may compress this nerve with resultant pain radiating distally. Please rate this question:


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Obturator nerve

The obturator nerve arises from L2, L3 and L4 by branches from the ventral divisions of each of these nerve roots. L3 forms the main contribution and the second lumbar branch is occasionally absent. These branches unite in the substance of psoas major, descending vertically in its posterior part to emerge from its medial border at the lateral margin of the sacrum. It then crosses the sacroiliac joint to enter the lesser pelvis, it descends on obturator internus to enter the obturator groove. In the lesser pelvis the nerve lies lateral to the internal iliac vessels and ureter, and is joined by the obturator vessels lateral to the ovary or ductus deferens. Supplies

Medial compartment of thigh

Muscles supplied: external obturator, adductor longus, adductor brevis, adductor magnus (not the lower part-sciatic nerve), gracilis


The cutaneous branch is often absent. When present, it passes between gracilis and adductor longus near the middle part of the thigh, and supplies the skin and fascia of the distal two thirds of the medial aspect.

Obturator canal

Connects the pelvis and thigh: contains the obturator artery, vein, nerve which divides into anterior and posterior branches.

Cadaveric cross section demonstrating relationships of the obturator nerve


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http://en.wikipedia.org/wiki/Obturator%20nerve



Question 14 of 560

A 73 year old man presents with a tumour at the central aspect of the posterior third of the tongue. To which of the following lymph node groups is it most likely to metastasise?

Submental

Submandibular

Ipsilateral deep cervical nodes

Contralateral deep cervical nodes

Bilateral deep cervical nodes

Posterior third tumours of the tongue commonly metastasise to the bilateral deep cervical lymph nodes

Tumours of the posterior third of the tongue will typically metastasise early and bilateral nodal involvement is well recognised, this is most often true of centrally located tumours and those adjacent to the midline as the lymph vessels may cross the median plane at this location. Please rate this question:


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Lymphatic drainage of the tongue

The lymphatic drainage of the anterior two thirds of the tongue shows only minimal communication of lymphatics across the midline, so metastasis to the ipsilateral nodes is usual.

The lymphatic drainage of the posterior third of the tongue have communicating networks, as a result early bilateral nodal metastases are more common in this area.

Lymphatics from the tip of the tongue usually pass to the sub mental nodes and from there to the deep cervical nodes.

Lymphatics from the mid portion of the tongue usually drain to the submandibular nodes and then to the deep cervical nodes. Mid tongue tumours that are laterally located will usually drain to the ipsilateral deep cervical nodes, those from more central regions may have bilateral deep cervical nodal involvement.

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Question 15 of 560

A 6 month old child is brought to the surgical clinic because of non descended testes. What is the

main structure that determines the descent path of the testicle?

Processus vaginalis

Cremaster

Mesorchium

Inguinal canal

Gubernaculum

Theme from April 2012 exam


The gubernaculum is a ridge of mesenchymal tissue that connects the testis to the inferior aspect of

the scrotum. Early in embryonic development the gubernaculum is long and the testis are located on

the posterior abdominal wall. During foetal growth the body grows relative to the gubernaculum, with

resultant descent of the testis.



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Testicular embryology

Until the end of foetal life the testicles are located within the abdominal cavity. They are initially

located on the posterior abdominal wall on a level with the upper lumbar vertebrae (L2). Attached to

the inferior aspect of the testis is the gubernaculum testis which extends caudally to the inguinal

region, through the canal and down to the superficial skin. Both the testis and the gubernaculum are


extra-peritoneal.

As the foetus grows the gubernaculum becomes progressively shorter. It carries the peritoneum of

the anterior abdominal wall (the processus vaginalis). As the processus vaginalis descends the testis

is guided by the gubernaculum down the posterior abdominal wall and the back of the processus

vaginalis into the scrotum.

By the third month of foetal life the testes are located in the iliac fossae, by the seventh they lie at

the level of the deep inguinal ring.

The processus vaginalis usually closes after birth, but may persist and be the site of indirect hernias.

Part closure may result in development of cysts on the cord.

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Question 16 of 560

A 21 year old man undergoes surgical removal of an impacted 3rd molar. Post operatively, he is noted to have anaesthesia on the anterolateral aspect of the tongue. What is the most likely explanation?

Injury to the hypoglossal nerve

Injury to the inferior alveolar nerve

Injury to the lingual nerve

Injury to the mandibular branch of the facial nerve

Injury to the glossopharyngeal nerve

Theme from September 2014 exam The lingual nerve is closely related to the third molar and up to 10% of patients undergoing surgical extraction of these teeth may subsequently develop a lingual neuropraxia. The result is anaesthesia of the ipsilateral anterior aspect of the tongue. The inferior alveolar nerve innervates the teeth themselves. Please rate this question:


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Lingual nerve

Sensory nerve to the mucosa of the presulcal part of the tongue, floor of mouth and mandibular lingual gingivae

Arises from posterior trunk of the mandibular nerve Course runs past tensor veli palatini and lateral pterygoid (where it is joined by the chorda

tympani branch of the facial nerve). Emerging from the cover of the lateral pterygoid it proceeds antero inferiorly lying on the surface of the medial pterygoid and lies close to the medial aspect of the mandibular ramus. At the junction of the vertical and horizontal rami of the mandible it is anterior to the inferior alveolar nerve. It then passes below the mandibular attachment of the superior pharyngeal constrictor. Eventually, it lies on the periosteum of the root of the third molar tooth. It then passes medial to the mandibular origin of mylohyoid and then passes forwards on the inferior surface of this muscle

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Question 17 of 560

What is the most important structure involved in supporting the uterus?

Round ligament

Broad ligament

Uterosacral ligaments

Cardinal ligaments

Central perineal tendon


The central perineal tendon provides the main structural support to the uterus. Damage to this

structure is commonly associated with the development of pelvic organ prolapse, even when other

structures are intact.



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Uterus

The non pregnant uterus resides entirely within the pelvis. The peritoneum invests the uterus and

the structure is contained within the peritoneal cavity. The blood supply to the uterine body is via the

uterine artery (branch of the internal iliac). The uterine artery passes from the inferior aspect of the

uterus (lateral to the cervix) and runs alongside the uterus. It frequently anastomoses with the

ovarian artery superiorly. Inferolaterally the ureter is a close relation and ureteric injuries are a

recognised complication when pathology brings these structures into close proximity.


The supports of the uterus include the central perineal tendon (the most important). The lateral

cervical, round and uterosacral ligaments are condensations of the endopelvic fascia and provide

additional structural support.

Topography of the uterus


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http://en.wikipedia.org/wiki/Uterus



Question 18 of 560

A 34 year old lady suffers from hyperparathyroidism. The right inferior parathyroid is identified as having an adenoma and is scheduled for resection. From which of the following embryological structures is it derived?

Second pharyngeal pouch

Third pharyngeal pouch

Fourth pharyngeal pouch

First pharyngeal pouch

None of the above

The inferior parathyroid is a derivative of the third pharyngeal pouch. The superior parathyroid originates from the fourth pharyngeal pouch. Please rate this question:


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Parathyroid glands- anatomy

Four parathyroid glands Located posterior to the thyroid gland They lie within the pretracheal fascia

Embryology The parathyroids develop from the extremities of the third and fourth pharyngeal pouches. The parathyroids derived from the fourth pharyngeal pouch are located more superiorly and are associated with the thyroid gland. Those derived from the third pharyngeal pouch lie more inferiorly and may become associated with the thymus. Blood supply The blood supply to the parathyroid glands is derived from the inferior and superior thyroid arteries[1]. There is a rich anastomosis between the two vessels. Venous drainage is into the thyroid veins.


Relations

Laterally Common carotid

Medially Recurrent laryngeal nerve, trachea

Anterior Thyroid

Posterior Pretracheal fascia

References 1.Nobori, M., et al., Blood supply of the parathyroid gland from the superior thyroid artery. Surgery, 1994. 115(4): p. 417-23.

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Question 19 of 560

A 23 year old man falls and slips at a nightclub. A shard of glass penetrates the skin at the level of the medial epicondyle, which of the following sequelae is least likely to occur?

Atrophy of the first dorsal interosseous muscle

Difficulty in abduction of the the 2nd, 3rd, 4th and 5th fingers

Claw like appearance of the hand

Loss of sensation on the anterior aspect of the 5th finger

Partial denervation of flexor digitorum profundus

Injury to the ulnar nerve in the mid to distal forearm will typically produce a claw hand. This consists of flexion of the 4th and 5th interphalangeal joints and extension of the metacarpophalangeal joints. The effects are potentiated when flexor digitorum profundus is not affected, and the clawing is more pronounced.More proximally sited ulnar nerve lesions produce a milder clinical picture owing to the simultaneous paralysis of flexor digitorum profundus (ulnar half).

This is the 'ulnar paradox', due to the more proximal level of transection the hand will typically not have a claw like appearance that may be seen following a more distal injury. The first dorsal interosseous muscle will be affected as it is supplied by the ulnar nerve. Please rate this question:


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Ulnar nerve

Origin

C8, T1

Supplies (no muscles in the upper arm)

Flexor carpi ulnaris


Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi

Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis

Path

Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially through the flexor retinaculum into the palm of the hand.


Branches

http://en.wikipedia.org/wiki/Ulnar%20nerve



Branch Supplies

Muscular branch Flexor carpi ulnaris

Medial half of the flexor digitorum profundus

Palmar cutaneous branch (Arises near the middle of the forearm)

Skin on the medial part of the palm

Dorsal cutaneous branch Dorsal surface of the medial part of the hand

Superficial branch Cutaneous fibres to the anterior surfaces of the

medial one and one-half digits

Deep branch Hypothenar muscles

All the interosseous muscles

Third and fourth lumbricals

Adductor pollicis Medial head of the flexor pollicis brevis

Effects of injury

Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand)

Wasting and paralysis of hypothenar muscles

Loss of sensation medial 1 and half fingers

Damage at the elbow Radial deviation of the wrist

Clawing less in 4th and 5th digits

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Question 20 of 560

A 56 year old man is undergoing a superficial parotidectomy for a pleomorphic adenoma. During the dissection of the parotid, which of the following structures will be encountered lying most superficially?

Facial nerve

External carotid artery

Occipital artery

Maxillary artery

Retromandibular vein

Most superficial structure on the parotid gland = facial nerve

The facial nerve is the most superficial structure in the parotid gland. Slightly deeper to this lies the retromandibular vein, with the arterial layer lying most deeply. Please rate this question:


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Parotid gland

Anatomy of the parotid gland

Location Overlying the mandibular ramus; anterior and inferior to the ear.

Salivary duct Crosses the masseter, pierces the buccinator and drains adjacent to the

2nd upper molar tooth (Stensen's duct).

Structures passing

through the gland

Facial nerve (Mnemonic: The Zebra Buggered My Cat; Temporal

Zygomatic, Buccal, Mandibular, Cervical)

External carotid artery

Retromandibular vein


Auriculotemporal nerve

Relations Anterior: masseter, medial pterygoid, superficial temporal and

maxillary artery, facial nerve, stylomandibular ligament

Posterior: posterior belly digastric muscle, sternocleidomastoid,

stylohyoid, internal carotid artery, mastoid process, styloid

process

Arterial supply Branches of external carotid artery

Venous drainage Retromandibular vein

Lymphatic drainage Deep cervical nodes

Nerve innervation Parasympathetic-Secretomotor

Sympathetic-Superior cervical ganglion

Sensory- Greater auricular nerve

Parasympathetic stimulation produces a water rich, serous saliva. Sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva.

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Question 21 of 560

A 43 year old man is stabbed outside a nightclub. He suffers a transection of his median nerve just as it leaves the brachial plexus. Which of the following features is least likely to ensue?

Ulnar deviation of the wrist

Complete loss of wrist flexion

Loss of pronation

Loss of flexion at the thumb joint

Inability to oppose the thumb

Loss of the median nerve will result in loss of function of the flexor muscles. However, flexor carpi ulnaris will still function and produce ulnar deviation and some residual wrist flexion. High median nerve lesions result in complete loss of flexion at the thumb joint. Please rate this question:


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Median nerve

The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches

Region Branch


Region Branch

Upper arm No branches, although the nerve commonly communicates with the

musculocutaneous nerve

Forearm Pronator teres

Flexor carpi radialis

Palmaris longus

Flexor digitorum superficialis

Flexor pollicis longus Flexor digitorum profundus (only the radial half)

Distal

forearm

Palmar cutaneous branch

Hand (Motor)

Motor supply (LOAF)

Lateral 2 lumbricals

Opponens pollicis

Abductor pollicis brevis

Flexor pollicis brevis

Hand

(Sensory)

Over thumb and lateral 2 ½ fingers

On the palmar aspect this projects proximally, on the dorsal aspect only the

distal regions are innervated with the radial nerve providing the more

proximal cutaneous innervation.

Patterns of damage Damage at wrist

e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand

deformity)

sensory loss to palmar aspect of lateral (radial) 2 ½ fingers

Damage at elbow, as above plus:

unable to pronate forearm weak wrist flexion ulnar deviation of wrist

Anterior interosseous nerve (branch of median nerve)

leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index

finger

Topography of the median nerve


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http://en.wikipedia.org/wiki/Median%20nerve



Question 22 of 560

A 78 year old man is due to undergo an endarterectomy of the internal carotid artery. Which of the following nervous structures are most at risk during the dissection?

Recurrent laryngeal nerve

Sympathetic chain

Hypoglossal nerve

Phrenic nerve

Lingual nerve

Nerves at risk during a carotid endarterectomy:

Hypoglossal nerve

Greater auricular nerve Superior laryngeal nerve

Theme from May 2011 exam Theme from January 2013 Exam During a carotid endarterectomy the sternocleidomastoid muscle is dissected, with ligation of the common facial vein and then the internal jugular is dissected exposing the common and the internal carotid arteries. The nerves at risk during the operation include:

Hypoglossal nerve Greater auricular nerve Superior laryngeal nerve

The sympathetic chain lies posteriorly and is less prone to injury in this procedure. Please rate this question:


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Internal carotid artery


The internal carotid artery is formed from the common carotid opposite the upper border of the thyroid cartilage. It extends superiorly to enter the skull via the carotid canal. From the carotid canal it then passes through the cavernous sinus, above which it divides into the anterior and middle cerebral arteries. Relations in the neck

Posterior Longus capitis

Pre-vertebral fascia

Sympathetic chain

Superior laryngeal nerve

Medially External carotid (near origin)

Wall of pharynx

Ascending pharyngeal artery

Laterally Internal jugular vein (moves posteriorly at entrance to skull)

Vagus nerve (most posterolaterally)

Anteriorly Sternocleidomastoid

Lingual and facial veins

Hypoglossal nerve

Relations in the carotid canal

Internal carotid plexus Cochlea and middle ear cavity Trigeminal ganglion (superiorly) Leaves canal lies above the foramen lacerum

Path and relations in the cranial cavity

The artery bends sharply forwards in the cavernous sinus, the aducens nerve lies close to its inferolateral aspect. The oculomotor, trochlear, opthalmic and, usually, the maxillary nerves lie in the lateral wall of the sinus. Near the superior orbital fissure it turns posteriorly and passes postero-medially to pierce the roof of the cavernous sinus inferior to the optic nerve. It then passes between the optic and oculomotor nerves to terminate below the anterior perforated substance by dividing into the anterior and middle cerebral arteries. Branches

Anterior and middle cerebral artery

Ophthalmic artery Posterior communicating artery

Anterior choroid artery Meningeal arteries Hypophyseal arteries

Image demonstrating the internal carotid artery and its relationship to the external carotid artery


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http://en.wikipedia.org/wiki/Internal%20carotid%20artery



Question 23 of 560

Which of the structures listed below articulates with the head of the radius superiorly?

Capitulum

Trochlea

Lateral epicondyle

Ulna

Medial epicondyle

Theme from September 2016 Exam The head of the radius articulates with the capitulum of the humerus. Please rate this question:


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Radius

The radius is one of the two long forearm bones that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, of which the distal end is the larger. Key points relating to its topography and relations are outlined below; Upper end

Articular cartilage- covers medial > lateral side Articulates with radial notch of the ulna by the annular ligament

Muscle attachment- biceps brachii at the tuberosity

Shaft

Muscle attachment

Upper third of the body Supinator

Flexor digitorum superficialis


Flexor pollicis longus

Middle third of the body Pronator teres

Lower quarter of the body Pronator quadratus

Tendon of supinator longus

Lower end

Quadrilateral Anterior surface- capsule of wrist joint

Medial surface- head of ulna Lateral surface- ends in the styloid process Posterior surface: 3 grooves containing:

1. Tendons of extensor carpi radialis longus and brevis 2. Tendon of extensor pollicis longus 3. Tendon of extensor indicis


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http://en.wikipedia.org/wiki/Radius%20%28bone%29



Question 24 of 560

Which of the following fascial structures encases the apex of the lungs?

Waldeyers fascia

Sibsons fascia

Pretracheal fascia

Clavipectoral fascia

None of the above

Sibson's fascia overlies the apices of both lungs

The suprapleural fascia (Sibson's fascia) runs from C7 to the first rib and overlies the apex of both lungs.It lies between the parietal pleura and the thoracic cage. Please rate this question:


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Lung anatomy

The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung

Base: diaphragm

Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and

behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament


Right lung

Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies.


Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta.

http://en.wikipedia.org/wiki/Right%20lung




Inferior borders of both lungs

6th rib in mid clavicular line

8th rib in mid axillary line 10th rib posteriorly

The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments

Segment number Right lung Left lung

1 Apical Apical

2 Posterior Posterior

3 Anterior Anterior

4 Lateral Superior lingular

5 Medial Inferior lingular

6 Superior (apical) Superior (apical)

http://en.wikipedia.org/wiki/Left%20lung




7 Medial basal Medial basal

8 Anterior basal Anterior basal

9 Lateral basal Lateral basal

10 Posterior basal Posterior basal

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Question 25 of 560

Which of the structures listed below inserts into the site labelled in the image.

© Image provided by the University of Sheffield

Psoas minor

Psoas major

Sartorius

Obturator externus

Gemellus

Psoas major inserts onto the lesser trochanter. Please rate this question:


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Femur

Extends from a rounded head, which articulates with the acetabulum down to the knee joint where the two large condyles at it's inferior aspect articulate with the tibia.

The superior aspect comprises a head and neck which pass inferolaterally to the body and the two trochanters. These lie at the junction between the neck and the body.

The neck meets the body of the femur at an angle of 125o.

Developmentally, the neck is part of the body but is demarcated from it by a wide rough intertrochanteric crest, this continues inferomedially as a spiral line that runs below the lesser trochanter. Medially, the intertrochanteric line gives attachment to the inferior end of the iliofemoral ligament. The neck is covered by synovial membrane up to the intertrochanteric line. The posterior aspect of the neck is demarcated from the shaft by the intertrochanteric crest and only it's medial aspect is covered by synovium and the joint capsule.

The greater trochanter has discernible surfaces that form the site of attachment of the gluteal muscles.Laterally, the greater trochanter overhangs the body and this forms part of the origin of vastus lateralis

Viewed anteriorly, the body of the femur appears rounded. Viewed laterally, it has an anterior concavity which gives fullness to the anterior thigh. Posteriorly, there is a ridge of bone, the linea aspera. The surface of the anterior aspect of the body forms the origin of the vastus intermedius. More medially, it forms the origin of vastus medialis.

The upper and middle aspects of the linea aspera form part of the origin of the attachments of the thigh adductors. Inferiorly, it spans out to form the bony floor of the popliteal fossa. At the inferior aspect of the popliteal surface the surface curves posteriorly to form the femoral condyles.

The structures that are attached to the inferior aspect of the linea aspera split with it as it approaches the popliteal fossa. Thus the vastus medialis and adductor magnus continue with the medial split and the biceps femoris and vastus intermedius along the lateral split.


http://d2zgo9qer4wjf4.cloudfront.net/images_eMRCS/bbb047b.jpg


Image demonstrating anterior aspect of femur with muscular attachments


Blood supply

The femur has a rich blood supply and numerous vascular foramina exist throughout it's length. The blood supply to the femoral head is clinically important and is provided by the medial circumflex femoral and lateral circumflex femoral arteries (Branches of profunda femoris). Also from the inferior gluteal artery. These form an anastomosis and travel to up the femoral neck to supply the head.

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Question 26 of 560

As regards the internal jugular vein, which of the following statements is untrue?

It lies within the carotid sheath

It is the continuation of the sigmoid sinus

The terminal part of the thoracic duct crosses anterior to it to insert into the right subclavian

vein

The hypoglossal nerve is closely related to it as it passes near the atlas

The vagus nerve is closely related to it within the carotid sheath




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Internal jugular vein

Each jugular vein begins in the jugular foramen, where they are the continuation of the sigmoid

sinus. They terminate at the medial end of the clavicle where they unite with the subclavian vein.

The vein lies within the carotid sheath throughout its course. Below the skull the internal carotid

artery and last four cranial nerves are anteromedial to the vein. Thereafter it is in contact medially

with the internal (then common) carotid artery. The vagus lies posteromedially.

At its superior aspect, the vein is overlapped by sternocleidomastoid and covered by it at the inferior

aspect of the vein.


Below the transverse process of the atlas it is crossed on its lateral side by the accessory nerve. At

its mid point it is crossed by the inferior root of the ansa cervicalis.

Posterior to the vein are the transverse processes of the cervical vertebrae, the phenic nerve as it

descends on the scalenus anterior, and the first part of the subclavian artery.

On the left side its also related to the thoracic duct.


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http://en.wikipedia.org/wiki/Jugular%20vein



Question 27 of 560

A 28 year old man requires a urethral catheter to be inserted prior to undergoing a splenectomy.

Where is the first site of resistance to be encountered on inserting the catheter?

Bulbar urethra

Membranous urethra

Internal sphincter

Prostatic urethra

Bladder neck

Theme from January 2012 Exam


The membranous urethra is the least distensible portion of the urethra. This is due to the fact that it

is surrounded by the external sphincter.



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Urethral anatomy

Female urethra

The female urethra is shorter and more acutely angulated than the male urethra. It is an extra-

peritoneal structure and embedded in the endopelvic fascia. The neck of the bladder is subjected to

transmitted intra-abdominal pressure and therefore deficiency in this area may result in stress

urinary incontinence. Between the layers of the urogenital diaphragm the female urethra is

surrounded by the external urethral sphincter, this is innervated by the pudendal nerve. It ultimately


lies anterior to the vaginal orifice.

Male urethra

In males the urethra is much longer and is divided into four parts.

Pre-prostatic

urethra

Extremely short and lies between the bladder and prostate gland.It has a stellate lumen

and is between 1 and 1.5cm long.Innervated by sympathetic noradrenergic fibres, as

this region is composed of striated muscles bundles they may contract and prevent

retrograde ejaculation.

Prostatic

urethra

This segment is wider than the membranous urethra and contains several openings for

the transmission of semen (at the midpoint of the urethral crest).

Membranous

urethra

Narrowest part of the urethra and surrounded by external sphincter. It traverses the

perineal membrane 2.5cm postero-inferior to the symphysis pubis.

Penile urethra Travels through the corpus spongiosum on the underside of the penis. It is the longest

urethral segment.It is dilated at its origin as the infrabulbar fossa and again in the gland

penis as the navicular fossa. The bulbo-urethral glands open into the spongiose section

of the urethra 2.5cm below the perineal membrane.

The urothelium is transitional in nature near to the bladder and becomes squamous more distally.

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Question 28 of 560

Which of the following anatomical structures lies within the spiral groove of the humerus?

Median nerve

Radial nerve

Tendon of triceps

Musculocutaneous nerve

Axillary nerve


The radial nerve lies in this groove and may be compromised by fractures involving the shaft.



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Humerus

The humerus extends from the scapula to the elbow joint. It has a body and two ends. It is almost

completely covered with muscle but can usually be palpated throughout its length. The smooth

rounded surface of the head articulates with the shallow glenoid cavity. The head is connected to the

body of the humerus by the anatomical neck. The surgical neck is the region below the head and

tubercles and where they join the shaft and is the commonest site of fracture. The capsule of the

shoulder joint is attached to the anatomical neck superiorly but extends down to 1.5cm on the

surgical neck.

The greater tubercle is the prominence on the lateral side of the upper end of the bone. It merges


with the body below and can be felt through the deltoid inferior to the acromion. The tendons of the

supraspinatus and infraspinatus are inserted into impressions on its superior aspect. The lesser

tubercle is a distinct prominence on the front of the upper end of the bone. It can be palpated

through the deltoid just lateral to the tip of the coracoid process.

The intertubercular groove passes on the body between the greater and lesser tubercles, continuing

down from the anterior borders of the tubercles to form the edges of the groove. The tendon of

biceps within its synovial sheath passes through this groove, held within it by a transverse ligament.

The posterior surface of the body is marked by a spiral groove for the radial nerve which runs

obliquely across the upper half of the body to reach the lateral border below the deltoid tuberosity.

Within this groove lie the radial nerve and brachial vessels and both may be affected by fractures

involving the shaft of the humerus.

The lower end of the humerus is wide and flattened anteroposteriorly, and inclined anteriorly. The

middle third of the distal edge forms the trochlea. Superior to this are indentations for the coronoid

fossa anteriorly and olecranon fossa posteriorly. Lateral to the trochlea is a rounded capitulum which

articulates with the radius.

The medial epicondyle is very prominent with a smooth posterior surface which contains a sulcus for

the ulnar nerve and collateral vessels. It's distal margin gives attachment for the ulnar collateral

ligament and, in front of this, the anterior surface has an impression for the common flexor tendon.

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Question 29 of 560

A 24 year old man falls and sustains a fracture through his scaphoid bone. From which of the

following areas does the scaphoid derive the majority of its blood supply?

From its proximal medial border

From its proximal lateral border

From its proximal posterior surface

From the proximal end

From the distal end



The blood supply to the scaphoid enters from a small non articular surface near its distal end.

Transverse fractures through the scaphoid therefore carry a risk of non union.



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Scaphoid bone

The scaphoid has a concave articular surface for the head of the capitate and at the edge of this is a

crescentic surface for the corresponding area on the lunate.

Proximally, it has a wide convex articular surface with the radius. It has a distally sited tubercle that

can be palpated. The remaining articular surface is to the lateral side of the tubercle. It faces laterally

and is associated with the trapezium and trapezoid bones.


The narrow strip between the radial and trapezial surfaces and the tubercle gives rise to the radial

collateral carpal ligament. The tubercle receives part of the flexor retinaculum. This area is the only

part of the scaphoid that is available for the entry of blood vessels. It is commonly fractured and

avascular necrosis may result.

Scaphoid bone


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http://en.wikipedia.org/wiki/Scaphoid%20bone



Question 30 of 560

A 21 year old man has an inguinal hernia and is undergoing a surgical repair. As the surgeons approach the inguinal canal they expose the superficial inguinal ring. Which of the following forms the lateral edge of this structure?

Inferior epigastric artery

Conjoint tendon

Rectus abdominis muscle


Transversalis fascia

The external oblique aponeurosis forms the anterior wall of the inguinal canal and also the lateral edge of the superficial inguinal ring. The rectus abdominis lies posteromedially and the transversalis posterior to this. Please rate this question:


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Inguinal canal

Location

Above the inguinal ligament The inguinal canal is 4cm long The superficial ring is located anterior to the pubic tubercle The deep ring is located approximately 1.5-2cm above the half way point between the

anterior superior iliac spine and the pubic tubercle

Boundaries of the inguinal canal

Floor External oblique aponeurosis

Inguinal ligament


Lacunar ligament

Roof Internal oblique

Transversus abdominis

Anterior wall External oblique aponeurosis

Posterior wall Transversalis fascia

Conjoint tendon

Laterally Internal ring

Fibres of internal oblique

Medially External ring

Conjoint tendon

Contents

Males Spermatic cord and ilioinguinal

nerve

As it passes through the canal the spermatic cord

has 3 coverings:

External spermatic fascia from external

oblique aponeurosis

Cremasteric fascia

Internal spermatic fascia

Females Round ligament of uterus and

ilioinguinal nerve

Related anatomy of the inguinal region The boundaries of Hesselbachs triangle are commonly tested and illustrated below:


The image below demonstrates the close relationship of the vessels to the lower limb with the inguinal canal. A fact to be borne in mind when repairing hernial defects in this region.


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http://en.wikipedia.org/wiki/Inguinal%20triangle

http://en.wikipedia.org/wiki/Inguinal%20canal





Question 31 of 560

Which of the following cranial venous sinuses is unpaired?

Transverse sinus

Superior sagittal sinus

Cavernous sinus

Sigmoid sinus

Inferior petrosal sinus

The superior sagittal sinus is unpaired

The superior sagittal sinus is unpaired. It begins at the crista galli, where it may communicate with

the veins of the frontal sinus and sometimes with those of the nasal cavity. It arches backwards in

the falx cerebri to terminate at the internal occipital protuberance (usually into the right transverse

sinus). The parietal emissary veins link the superior sagittal sinus with the veins on the exterior of

the cranium.



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Cranial venous sinuses

The cranial venous sinuses are located within the dura mater. They have no valves which is

important in the potential for spreading sepsis. They eventually drain into the internal jugular vein.

They are:


Superior sagittal sinus

Inferior sagittal sinus

Straight sinus

Transverse sinus

Sigmoid sinus

Confluence of sinuses

Occipital sinus

Cavernous sinus

Topography of cranial venous sinuses


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http://en.wikipedia.org/wiki/Dural%20venous%20sinuses



Question 32 of 560

Which of the following laryngeal tumours will not typically metastasise to the cervical lymph nodes?

Glottic

Supraglottic

Subglottic

Transglottic

Aryepiglottic fold

The vocal cords have no lymphatic drainage and therefore this region serves as a lymphatic watershed. The supraglottic part drains to the upper deep cervical nodes through vessels piercing the thyrohyoid membrane. The sub glottic part drains to the pre laryngeal, pre tracheal and inferior deep cervical nodes. The aryepiglottic and vestibular folds have a rich lymphatic drainage and will metastasise early. Please rate this question:


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Larynx

The larynx lies in the anterior part of the neck at the levels of C3 to C6 vertebral bodies. The laryngeal skeleton consists of a number of cartilagenous segments. Three of these are paired; arytenoid, corniculate and cuneiform. Three are single; thyroid, cricoid and epiglottic. The cricoid cartilage forms a complete ring (the only one to do so). The laryngeal cavity extends from the laryngeal inlet to the level of the inferior border of the cricoid cartilage. Divisions of the laryngeal cavity

Laryngeal vestibule Superior to the vestibular folds

Laryngeal ventricle Lies between vestibular folds and superior to the vocal cords


Infraglottic cavity Extends from vocal cords to inferior border of the cricoid cartilage

The vocal folds (true vocal cords) control sound production. The apex of each fold projects medially into the laryngeal cavity. Each vocal fold includes:

Vocal ligament

Vocalis muscle (most medial part of thyroarytenoid muscle)

The glottis is composed of the vocal folds, processes and rima glottidis. The rima glottidis is the narrowest potential site within the larynx, as the vocal cords may be completely opposed, forming a complete barrier. Muscles of the larynx

Muscle Origin Insertion Innervation Action

Posterior

cricoarytenoid

Posterior aspect

of lamina of cricoid

Muscular process

of arytenoid

Recurrent

Laryngeal

Abducts vocal fold

Lateral

cricoarytenoid

Arch of cricoid Muscular process

of arytenoid

Recurrent

laryngeal

Adducts vocal fold

Thyroarytenoid Posterior aspect

of thyroid

cartilage

Muscular process of arytenoid

Recurrent laryngeal

Relaxes vocal fold

Transverse and

oblique

arytenoids

Arytenoid cartilage

Contralateral arytenoid

Recurrent laryngeal

Closure of

intercartilagenous

part of the rima glottidis

Vocalis Depression

between lamina

of thyroid cartilage

Vocal ligament

and vocal process

of arytenoid cartilage

Recurrent laryngeal

Relaxes posterior

vocal ligament, tenses

anterior part

Cricothyroid Anterolateral Inferior margin

and horn of

External Tenses vocal fold

Muscle Origin Insertion Innervation Action

part of cricoid thyroid cartilage laryngeal

Blood supply Arterial supply is via the laryngeal arteries, branches of the superior and inferior thyroid arteries. The superior laryngeal artery is closely related to the internal laryngeal nerve. The inferior laryngeal artery is related to the inferior laryngeal nerve. Venous drainage is via superior and inferior laryngeal veins, the former draining into the superior thyroid vein and the latter draining into the middle thyroid vein, or thyroid venous plexus. Lymphatic drainage The vocal cords have no lymphatic drainage and this site acts as a lymphatic watershed.

Supraglottic part Upper deep cervical nodes

Subglottic part Prelaryngeal and pretracheal nodes and inferior deep cervical nodes

The aryepiglottic fold and vestibular folds have a dense plexus of lymphatics associated with them and malignancies at these sites have a greater propensity for nodal metastasis. Topography of the larynx


http://en.wikipedia.org/wiki/Larynx



Question 33 of 560

Which of the following forms the medial wall of the femoral canal?

Pectineal ligament

Adductor longus

Sartorius

Lacunar ligament

Inguinal ligament

The femoral canal and the femoral triangle are distinct anatomical structures. Do not confuse them, especially in the time pressured exam situation.

Theme from September 2011 exam Theme from September 2012 exam Theme from April 2014 exam Please rate this question:


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Femoral canal

The femoral canal lies at the medial aspect of the femoral sheath. The femoral sheath is a fascial tunnel containing both the femoral artery laterally and femoral vein medially. The canal lies medial to the vein. Borders of the femoral canal

Laterally Femoral vein

Medially Lacunar ligament


Anteriorly Inguinal ligament

Posteriorly Pectineal ligament

Image showing dissection of femoral canal


Contents

Lymphatic vessels Cloquet's lymph node

Physiological significance Allows the femoral vein to expand to allow for increased venous return to the lower limbs.

http://en.wikipedia.org/wiki/Femoral%20canal



Pathological significance As a potential space, it is the site of femoral hernias. The relatively tight neck places these at high risk of strangulation.

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Question 34 of 560

A 67 year old man is undergoing a transurethral resection of a bladder tumour using diathermy. Suddenly during the procedure the patient's thigh begins to twitch. Stimulation of which of the following nerves is the most likely cause?

Femoral

Pudendal

Sciatic

Obturator

Gluteal

Theme from January 2011 Exam Theme from January 2013 Exam The obturator nerve is most closely related to the bladder (see below)




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Obturator nerve

The obturator nerve arises from L2, L3 and L4 by branches from the ventral divisions of each of these nerve roots. L3 forms the main contribution and the second lumbar branch is occasionally absent. These branches unite in the substance of psoas major, descending vertically in its posterior part to emerge from its medial border at the lateral margin of the sacrum. It then crosses the sacroiliac joint to enter the lesser pelvis, it descends on obturator internus to enter the obturator groove. In the lesser pelvis the nerve lies lateral to the internal iliac vessels and ureter, and is joined by the obturator vessels lateral to the ovary or ductus deferens. Supplies

Medial compartment of thigh

Muscles supplied: external obturator, adductor longus, adductor brevis, adductor magnus (not the lower part-sciatic nerve), gracilis

The cutaneous branch is often absent. When present, it passes between gracilis and adductor longus near the middle part of the thigh, and supplies the skin and fascia of the distal two thirds of the medial aspect.





Obturator canal

Connects the pelvis and thigh: contains the obturator artery, vein, nerve which divides into anterior and posterior branches.

Cadaveric cross section demonstrating relationships of the obturator nerve


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Question 35 of 560

A 5 year old boy is playing with some small ball bearings. Unfortunately he inhales one. To which of the following lung regions is the ball most likely to settle?

Right lower lobe

Left main bronchus

Right upper lobe

Left lower lobe

None of the above

Theme from September 2011 Exam Theme from January 2013 Exam As the most dependent part of the right lung a small object is most likely to lodge here. Most objects will preferentially enter the right lung owing to the angle the right main bronchus takes from the trachea. Please rate this question:


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Lung anatomy

The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung

Base: diaphragm

Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and

behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament


Right lung

Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies.


Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta.

http://en.wikipedia.org/wiki/Right%20lung




Inferior borders of both lungs

6th rib in mid clavicular line

8th rib in mid axillary line 10th rib posteriorly

The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments


1 Apical Apical

2 Posterior Posterior

3 Anterior Anterior

4 Lateral Superior lingular

5 Medial Inferior lingular

6 Superior (apical) Superior (apical)

http://en.wikipedia.org/wiki/Left%20lung




7 Medial basal Medial basal

8 Anterior basal Anterior basal

9 Lateral basal Lateral basal

10 Posterior basal Posterior basal

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Question 36 of 560

A patient presents with superior vena caval obstruction. How many collateral circulations exist as alternative pathways of venous return?

None

One

Two

Three

Four

There are 4 collateral venous systems:

Azygos venous system Internal mammary venous pathway Long thoracic venous system with connections to the femoral and vertebral veins (2

pathways)

Despite this, venous hypertension still occurs. Please rate this question:


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Superior vena cava

Drainage

Head and neck

Upper limbs Thorax Part of abdominal walls


Formation

Subclavian and internal jugular veins unite to form the right and left brachiocephalic veins These unite to form the SVC

Azygos vein joins the SVC before it enters the right atrium

Relations

Anterior Anterior margins of the right lung and pleura

Posteromedial Trachea and right vagus nerve

Posterolateral Posterior aspects of right lung and pleura

Pulmonary hilum is posterior

Right lateral Right phrenic nerve and pleura

Left lateral Brachiocephalic artery and ascending aorta

Developmental variations

Anomalies of the connection of the SVC are recognised. In some individuals a persistent left sided SVC drains into the right atrium via an enlarged orifice of the coronary sinus. More rarely the left sided vena cava may connect directly with the superior aspect of the left atrium, usually associated with an un-roofing of the coronary sinus. The commonest lesion of the IVC is for its abdominal course to be interrupted, with drainage achieved via the azygos venous system. This may occur in patients with left sided atrial isomerism.

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Question 37 of 560

An 18 year old man is cutting some plants when a small piece of vegetable matter enters his eye.

His eye becomes watery. Which of the following is responsible for relaying parasympathetic

neuronal signals to the lacrimal apparatus?

Pterygopalatine ganglion

Otic ganglion

Submandibular ganglion

Ciliary ganglion

None of the above

Theme from January 2013 Exam

The parasympathetic fibres to the lacrimal apparatus transit via the pterygopalatine ganglion.



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Lacrimal system

Lacrimal gland

Consists of an orbital part and palpebral part. They are continuous posterolaterally around the

concave lateral edge of the levator palpebrae superioris muscle.

The ducts of the lacrimal gland open into the superior fornix. Those from the orbital part penetrate

the aponeurosis of levator palpebrae superioris to join those from the palpebral part. Therefore

excision of the palpebral part is functionally similar to excision of the entire gland.


Blood supply

Lacrimal branch of the opthalmic artery. Venous drainage is to the superior opthalmic vein.

Innervation

The gland is innervated by the secretomotor parasympathetic fibres from the pterygopalatine

ganglion which in turn may reach the gland via the zygomatic or lacrimal branches of the maxillary

nerve or pass directly to the gland. The preganglionic fibres travel to the ganglion in the greater

petrosal nerve (a branch of the facial nerve at the geniculate ganglion).

Nasolacrimal duct

Descends from the lacrimal sac to open anteriorly in the inferior meatus of the nose.

Lacrimation reflex

Occurs in response to conjunctival irritation (or emotional events). The conjunctiva will send signals

via the opthalmic nerve. These then pass to the superior salivary centre. The efferent signals pass

via the greater petrosal nerve (parasympathetic preganglionic fibres) and the deep petrosal nerve

which carries the post ganglionic sympathetic fibres. The parasympathetic fibres will relay in the

pterygopalatine ganglion, the sympathetic fibres do not synapse. They in turn will relay to the

lacrimal apparatus.

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Question 38 of 560

Which of the nerves listed below is directly responsible for the innervation of the lateral aspect of

flexor digitorum profundus?

Ulnar nerve

Anterior interosseous nerve

Radial nerve

Median nerve

Posterior interosseous nerve

The anterior interosseous nerve is a branch of the median nerve and is responsible for innervation of

the lateral aspect of the flexor digitorum profundus.



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Forearm flexor muscles

Muscle Origin Insertion Nerve supply Action

Flexor carpi

radialis

Common flexor

origin and

surrounding

Front of bases of second

and third metacarpals

Median Flexes and abducts the

carpus, part flexes the

elbow and part



fascia pronates forearm

Palmaris

longus

Common flexor

origin

Apex of palmar

aponeurosis

Median Wrist flexor

Flexor carpi

ulnaris

Small humeral

head arises from

the common

flexor origin and

adjacent fascia.

Ulnar head

comes from

medial border of

olecranon and

posterior border

of ulna

Pisiform and base of the

fifth metacarpal

Ulnar nerve Flexes and adducts the

carpus

Flexor

digitorum

superficialis

Long linear origin

from common

flexor tendon,

adjacent fascia

and septa and

medial border of

the coronoid

process

Via tendons in the fibrous

flexor sheath. At the level

of the

metacarpophalangeal

joint each tendon split

into two, these bands

pass distally to their

insertions

Median Flexor of

metacarpophalangeal

joint and proximal

interphalangeal joint

Flexor

digitorum

profundus

Upper two thirds

of the medial and

anterior surface

of the ulna,

medial side of the

olecranon,

medial half of the

interosseous

Via tendons that lie deep

to those of flexor

digitorum superficialis to

insert into the distal

phalanx

Medial part=

ulnar, lateral

part=anterior

interosseous

nerve

Flexes the distal

interphalangeal joints

and the wrist


membrane

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Question 39 of 560

A 45 year old lady is undergoing a Whipples procedure for carcinoma of the pancreatic head. The bile duct is transected. Which of the following vessels is mainly responsible for the blood supply to the bile duct?

Cystic artery

Hepatic artery

Portal vein

Left gastric artery

None of the above

Do not confuse the blood supply of the bile duct with that of the cystic duct.

Theme from April 2014 exam The bile duct has an axial blood supply which is derived from the hepatic artery and from retroduodenal branches of the gastroduodenal artery. Unlike the liver there is no contribution by the portal vein to the blood supply of the bile duct. Damage to the hepatic artery during a difficult cholecystectomy is a recognised cause of bile duct strictures. Please rate this question:


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Gallbladder

Fibromuscular sac with capacity of 50ml Columnar epithelium

Relations of the gallbladder

Anterior Liver


Posterior Covered by peritoneum

Transverse colon

1st part of the duodenum

Laterally Right lobe of liver

Medially Quadrate lobe of liver

Arterial supply Cystic artery (branch of Right hepatic artery) Venous drainage Directly to the liver Nerve supply

Sympathetic- mid thoracic spinal cord, Parasympathetic- anterior vagal trunk Common bile duct

Origin Confluence of cystic and common hepatic ducts

Relations at

origin

Medially - Hepatic artery

Posteriorly- Portal vein

Relations distally Duodenum - anteriorly

Pancreas - medially and laterally

Right renal vein - posteriorly

Arterial supply Branches of hepatic artery and retroduodenal branches of gastroduodenal

artery

Hepatobiliary triangle

Medially Common hepatic duct

Inferiorly Cystic duct

Superiorly Inferior edge of liver

Contents Cystic artery

Relations of the gallbladder


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Question 40 of 560

A 43 year old lady is undergoing a total thyroidectomy for an extremely large goitre. The surgeons decide that access may be improved by division of the infra hyoid strap muscles. At which of the following sites should they be divided?

In their upper half

In their lower half

In the middle

At their origin from the hyoid

At the point of their insertion

Theme from 2009 Exam Should the strap muscles require division during surgery they should be divided in their upper half. This is because their nerve supply from the ansa cervicalis enters in their lower half. Please rate this question:


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Anterior triangle of the neck

Boundaries

Anterior border of the Sternocleidomastoid

Lower border of mandible Anterior midline

Sub triangles (divided by Digastric above and Omohyoid)

Muscular triangle: Neck strap muscles

Carotid triangle: Carotid sheath


Submandibular Triangle (digastric)

Contents of the anterior triangle

Digastric triangle Submandibular gland

Submandibular nodes

Facial vessels

Hypoglossal nerve

Muscular triangle Strap muscles External jugular vein

Carotid triangle Carotid sheath (Common carotid, vagus and internal jugular vein)

Ansa cervicalis

Nerve supply to digastric muscle

Anterior: Mylohyoid nerve Posterior: Facial nerve


Next question

http://en.wikipedia.org/wiki/Anterior%20triangle%20of%20the%20neck



Question 41 of 560

A 7 year old boy presents with right iliac fossa pain and there is a clinical suspicion that appendicitis is present. From which of the following embryological structures is the appendix derived?

Vitello-intestinal duct

Uranchus

Foregut

Hindgut

Midgut

The appendix is derived from the midgut

Theme from April 2014 exam It is derived from the midgut which is why early appendicitis may present with periumbilical pain. Please rate this question:


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Appendix

Location: Base of caecum.

Up to 10cm long. Mainly lymphoid tissue (Hence mesenteric adenitis may mimic appendicitis). Caecal taenia coli converge at base of appendix and form a longitudinal muscle cover over

the appendix. This convergence should facilitate its identification at surgery if it is retrocaecal and difficult to find (which it can be when people start doing appendicectomies!)

Arterial supply: Appendicular artery (branch of the ileocolic). It is intra peritoneal.

McBurney's point

1/3 of the way along a line drawn from the Anterior Superior Iliac Spine to the Umbilicus


6 Positions:

Retrocaecal 74%

Pelvic 21% Postileal Subcaecal Paracaecal Preileal

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Question 42 of 560

A 22 year old women has recently undergone a surgical excision of the submandibular gland. She presents to the follow up clinic with a complaint of tongue weakness on the ipsilateral side to her surgery. Which nerve has been damaged?

Hypoglossal nerve

Lingual nerve

Inferior alveolar nerve

Facial nerve

Lesser petrosal nerve

Three cranial nerves may be injured during submandibular gland excision.

Marginal mandibular branch of the facial nerve Lingual nerve Hypoglossal nerve

Theme from April 2012 Exam Hypoglossal nerve damage may result in paralysis of the ipsilateral aspect of the tongue. The nerve itself lies deep to the capsule surrounding the gland and should not be injured during an intracapsular dissection. The lingual nerve is probably at greater risk of injury. However, the effects of lingual nerve injury are sensory rather than motor.




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Submandibular gland

Relations of the submandibular gland

Superficial Platysma, deep fascia and mandible

Submandibular lymph nodes

Facial vein (facial artery near mandible)

Marginal mandibular nerve

Cervical branch of the facial nerve

Deep Facial artery (inferior to the mandible)

Mylohoid muscle

Sub mandibular duct

Hyoglossus muscle

Lingual nerve

Submandibular ganglion

Hypoglossal nerve

Submandibular duct (Wharton's duct)

http://en.wikipedia.org/wiki/Mylohyoid%20nerve




Opens lateral to the lingual frenulum on the anterior floor of mouth. 5 cm length Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial

to the nerve to lie above it and then crosses back, lateral to it, to reach a position below the nerve.

Innervation

Sympathetic innervation- Derived from superior cervical ganglion

Parasympathetic innervation- Submandibular ganglion via lingual nerve

Arterial supply Branch of the facial artery. The facial artery passes through the gland to groove its deep surface. It then emerges onto the face by passing between the gland and the mandible. Venous drainage Anterior facial vein (lies deep to the Marginal Mandibular nerve) Lymphatic drainage Deep cervical and jugular chains of nodes

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Question 43 of 560

You decide to take an arterial blood gas from the femoral artery. Where should the needle be inserted to gain the sample?

Mid point of the inguinal ligament

Mid inguinal point

2cm inferomedially to the pubic tubercle

2cm superomedially to the pubic tubercle

3cm inferolaterally to the deep inguinal ring

The mid inguinal point is midway between the anterior superior iliac spine and the symphysis pubis

Theme from April 2015 Exam The mid inguinal point in the surface marking for the femoral artery. Please rate this question:


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Femoral triangle anatomy

Boundaries

Superiorly Inguinal ligament

Laterally Sartorius

Medially Adductor longus

Floor Iliopsoas, adductor longus and pectineus


Roof Fascia lata and Superficial fascia

Superficial inguinal lymph nodes (palpable below the inguinal ligament)

Long saphenous vein


Contents

Femoral vein (medial to lateral) Femoral artery-pulse palpated at the mid inguinal point

Femoral nerve Deep and superficial inguinal lymph nodes Lateral cutaneous nerve Great saphenous vein Femoral branch of the genitofemoral nerve

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http://en.wikipedia.org/wiki/Femoral%20triangle



Question 44 of 560

A 67 year old man undergoes a carotid endarterectomy and seems to recover well following surgery.

When he is reviewed on the ward post operatively he complains that his voice is hoarse. What is the

most likely cause?

Damage to the accessory nerve

Damage to the cervical plexus

Damage to the glossopharyngeal nerve

Damage to the hypoglossal nerve

Damage to the vagus


Many of these nerves are at risk of injury during carotid surgery. However, only damage to the vagus

would account for difficulties in speech.



Next question

Vagus nerve

The vagus nerve has mixed functions and supplies the structures from the fourth and sixth

pharyngeal arches. It also supplies the fore and midgut sections of the embryonic gut tube. It carries

afferent fibres from these areas (viz; pharynx, larynx, oesophagus, stomach, lungs, heart and great

vessels). The efferent fibres of the vagus are of two main types. The first are preganglionic

parasympathetic fibres distributed to the parasympathetic ganglia that innervate smooth muscle of

the innervated organs (such as gut). The second type of efferent fibres have direct skeletal muscle


innervation, these are largely to the muscles of the larynx and pharynx.

Origin and course

The vagus arises from the lateral surface of the medulla oblongata by a series of rootlets. It is

related to the glossopharyngeal nerve cranially and the accessory nerve caudally. It exits through

the jugular foramen and is contained within its own dural sheath alongside the accessory nerve. In

the neck it descends vertically in the carotid sheath where it is closely related to the internal and

common carotid arteries. It leaves the neck and enters the mediastinum. On the right it passes

anterior to the first part of the subclavian artery, on the left it lies in the interval between the common

carotid and subclavian arteries.

In the mediastinum both nerves pass postero-inferiorly and reach the posterior surface of the

corresponding lung root. These then branch into both lungs. At the inferior end of the mediastinum

these plexuses reunite to form the formal vagal trunks that pass through the oesophageal hiatus and

into the abdomen. The anterior and posterior vagal trunks are formal nerve fibres these then splay

out once again sending fibres over the stomach and posteriorly to the coeliac plexus. Branches pass

to the liver, spleen and kidney.

Communications and branches

Communication Details

Superior

ganglion

Located in jugular foramen

Communicates with the superior cervical sympathetic ganglion, accessory nerve

Two branches; meningeal and auricular (the latter may give rise to vagal stimulation

following instrumentation of the external auditory meatus)

Inferior ganglion Communicates with the superior cervical sympathetic ganglion, hypoglossal nerve and

loop between first and second cervical ventral rami

Two branches; pharyngeal (supplies pharyngeal muscles) and superior laryngeal nerve

(inferomedially- deep to both carotid arteries)

Branches in the neck

Branch Detail

Superior and inferior

cervical cardiac

branches

Arise at various points and descend into thorax

On the right these pass posterior to the subclavian artery

On the left the superior branch passes between the arch of the aorta and the

trachea to connect with the deep cardiac plexus. The inferior branch descends

Branch Detail

with the vagus itself.

Right recurrent

laryngeal nerve

Arises from vagus anterior to the first part of the subclavian artery, hooks under

it, and ascends superomedially. It passes close to the common carotid and finally

the inferior thyroid artery to insert into the larynx

Branches in the thorax

Branch Details

Left recurrent

laryngeal

nerve

Arises from the vagus on the aortic arch. It hooks around the inferior surface of the arch,

posterior to the ligamentum arteriosum and passes upwards through the superior

mediastinum and lower part of the neck. It lies in the groove between oesophagus and

trachea (supplies both). It passes with the inferior thyroid artery and inserts into the

larynx.

Thoracic and

cardiac

branches

There are extensive branches to both the heart and lung roots. These pass throughout

both these viscera. The fibres reunite distally prior to passing into the abdomen.

Abdominal branches

After entry into the abdominal cavity the nerves branch extensively. In previous years the extensive

network of the distal branches (nerves of Laterjet) over the surface of the distal stomach were

important for the operation of highly selective vagotomy. The use of modern PPI's has reduced the

need for such highly selective procedures. Branches pass to the coeliac axis and alongside the

vessels to supply the spleen, liver and kidney.

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Question 45 of 560

A 25 year old man has an inguinal hernia, which of the following structures must be divided (at open surgery) to gain access to the inguinal canal?

Transversalis fascia


Conjoint tendon

Rectus abdominis

Inferior epigastric artery

Theme from January 2013 Exam This question is asking what structure forms the anterior wall of the inguinal canal. The anterior wall is formed by the external oblique aponeurosis. Once this is divided the canal is entered, the cord can be mobilised and a hernia repair performed. The transversalis fascia and conjoint tendons form the posterior wall and would not routinely be divided to gain access to the inguinal canal itself. Please rate this question:


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External oblique muscle

External oblique forms the outermost muscle of the three muscles comprising the anterolateral aspect of the abdominal wall. Its aponeurosis comprises the anterior wall of the inguinal canal.

Origin Outer surfaces of the lowest eight ribs

Insertion Anterior two thirds of the outer lip of the iliac crest.

The remainder becomes the aponeurosis that fuses with the linea alba in the

midline.

Nerve Ventral rami of the lower six thoracic nerves


supply

Actions Contains the abdominal viscera, may contract to raise intra abdominal pressure.

Moves trunk to one side.

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Question 46 of 560

Which muscle initiates abduction of the shoulder?

Infraspinatus

Latissimus dorsi

Supraspinatus

Deltoid

Teres major

Theme from September 2012 exam Theme from April 2014 Exam The intermediate portion of the deltoid muscle is the chief abductor of the humerus. However, it can only do this after the movement has been initiated by supraspinatus. Damage to the tendon of supraspinatus is a common form of rotator cuff disease. Please rate this question:


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Shoulder joint

Shallow synovial ball and socket type of joint. It is an inherently unstable joint, but is capable to a wide range of movement. Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the

greater tuberosity (all except sub scapularis-lesser tuberosity).

Glenoid labrum

Fibrocartilaginous rim attached to the free edge of the glenoid cavity

Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum.

The long head of triceps attaches to the infraglenoid tubercle


Fibrous capsule

Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly)

Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly

Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion.

Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon.

The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis.

Movements and muscles

Flexion Anterior part of deltoid

Pectoralis major

Biceps

Coracobrachialis

Extension Posterior deltoid

Teres major

Latissimus dorsi

Adduction Pectoralis major

Latissimus dorsi

Teres major

Coracobrachialis

Abduction Mid deltoid Supraspinatus

Medial rotation Subscapularis

Anterior deltoid

Teres major

Latissimus dorsi

Lateral rotation Posterior deltoid

Infraspinatus Teres minor

Important anatomical relations

Anteriorly Brachial plexus Axillary artery and vein

Posterior Suprascapular nerve Suprascapular vessels

Inferior Axillary nerve

Circumflex humeral vessels

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Question 47 of 560

A 34 year old man is shot in the postero- inferior aspect of his thigh. Which of the following lies at the most lateral aspect of the popliteal fossa?

Popliteal artery

Popliteal vein

Common peroneal nerve

Tibial nerve

Small saphenous vein

Theme from April 2012 exam Theme from April 2014 exam The contents of the popliteal fossa are (from medial to lateral): Popliteal artery Popliteal vein Tibial nerve Common peroneal nerve The sural nerve is a branch of the tibial nerve and usually arises at the inferior aspect of the popliteal fossa. However, its anatomy is variable. Please rate this question:


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Popliteal fossa

Boundaries of the popliteal fossa

Laterally Biceps femoris above, lateral head of gastrocnemius and plantaris below

Medially Semimembranosus and semitendinosus above, medial head of gastrocnemius below


Floor Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle

Roof Superficial and deep fascia

Image showing the popliteal fossa


Contents

Popliteal artery and vein

Small saphenous vein Common peroneal nerve Tibial nerve Posterior cutaneous nerve of the thigh

Genicular branch of the obturator nerve Lymph nodes

Next question



Question 48 of 560

A 67 year old man has an abdominal aortic aneurysm which displaces the left renal vein. Which

branch of the aorta is most likely to affected at this level?

Inferior mesenteric artery

Superior mesenteric artery

Coeliac axis

Testicular artery

None of the above



The left renal vein lies behind of the SMA as it branches off the aorta. Whilst juxtarenal AAA may

sometimes require the division of the left renal vein, direct involvement of the SMA may require a

hybrid surgical bypass and subsequent endovascular occlusion.



Next question

Abdominal aortic branches

Branches Level Paired Type


Branches Level Paired Type

Inferior phrenic T12 (Upper border) Yes Parietal

Coeliac T12 No Visceral

Superior mesenteric L1 No Visceral

Middle suprarenal L1 Yes Visceral

Renal L1-L2 Yes Visceral

Gonadal L2 Yes Visceral

Lumbar L1-L4 Yes Parietal

Inferior mesenteric L3 No Visceral

Median sacral L4 No Parietal

Common iliac L4 Yes Terminal

Next question

Question 49 of 560

A 12 year old boy undergoes surgery for recurrent mastoid infections. Post operatively he complains of an altered taste sensation. Which of the following nerves has been injured?

Glossopharyngeal

Greater petrosal

Olfactory

Trigeminal

Chorda tympani

Theme from April 2012 exam Theme from April 2014 exam The chorda tympani branch of the facial nerve passes forwards through itrs canaliculus into the middle ear, and crosses the medial aspect of the tympanic membrane. It then passes antero-inferiorly in the infratemporal fossa. It distributes taste fibres to the anterior two thirds of the tongue.





Next question

Facial nerve

The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste. Supply - 'face, ear, taste, tear'

Face: muscles of facial expression Ear: nerve to stapedius Taste: supplies anterior two-thirds of tongue

Tear: parasympathetic fibres to lacrimal glands, also salivary glands

Path Subarachnoid path

Origin: motor- pons, sensory- nervus intermedius

Pass through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear nerve. Here they combine to become the facial nerve.

Facial canal path

The canal passes superior to the vestibule of the inner ear

At the medial aspect of the middle ear, it becomes wider and contains the geniculate ganglion.

- 3 branches: 1. greater petrosal nerve 2. nerve to stapedius 3. chorda tympani Stylomastoid foramen

Passes through the stylomastoid foramen (tympanic cavity anterior and mastoid antrum posteriorly)

Posterior auricular nerve and branch to posterior belly of digastric and stylohyoid muscle

http://en.wikipedia.org/wiki/Chorda%20tympani



Face

Enters parotid gland and divides into 5 branches:

Temporal branch

Zygomatic branch Buccal branch Marginal mandibular branch Cervical branch

Next question

Question 50 of 560

The first root of the brachial plexus commonly arises at which of the following levels?

C6

C5

C3

C2

C8

It begins at C5 and has 5 roots. It ends with a total of 15 nerves of these 5 are the main nerves to the upper limb (axillary, radial, ulnar, musculocutaneous and median) Please rate this question:


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Brachial plexus

Origin Anterior rami of C5 to T1

Sections of the

plexus

Roots, trunks, divisions, cords, branches

Mnemonic:Real Teenagers Drink Cold Beer

Roots Located in the posterior triangle

Pass between scalenus anterior and medius

Trunks Located posterior to middle third of clavicle

Upper and middle trunks related superiorly to the subclavian artery

Lower trunk passes over 1st rib posterior to the subclavian artery


Divisions Apex of axilla

Cords Related to axillary artery

Diagram illustrating the branches of the brachial plexus


Cutaneous sensation of the upper limb

http://en.wikipedia.org/wiki/Brachial%20plexus




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http://en.wikipedia.org/median%20nerve



foramina of the base of the skull - 1 file download

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