head and neck
DESCRIPTION
Global institute of medical sciences1. www.gims-org.com2. www.usmletutor.orgTRANSCRIPT
1. Posterior Compartment -Vertebrae and muscles which support and move head & neck
2. Anterior Compartment- Viscera and rostral continuation GI & Respiratory Systems
3. Lateral Compartment-Blood vessels & nerve
I. OVERVIEW OF NECK - neck is compartmentalized
Plane of section
HORIZONTAL SECTION THROUGH NECK
POST.
LAT.
ANT.
- muscles move head and neck
Post side - Deep Muscles (like back)- extensor & SuboccipitalMuscles
Lateral side -Scalene muscles - flex neck laterally
Anterior side -Prevertebral Muscles -directly anterior to vertebrae - flex head & neck
1. POSTERIOR COMPARTMENT
BACK+ SUBOCCIPMUSCLES
SCALENEMUSCLES
PRE-VERTEBRALMUSCLES
In thorax, trachea is anterior to esophagus
2. ANTERIOR COMPARTMENT - VISCERA
Trachea
Esophagus
Anterior Compartment -Larynx is part of upper end of respiratory system-specialized for sound production; also acts as ‘sphincter’ of respiratory system-Thyroid cartilage is Adam's apple
Larynx
Trachea
ANTERIOR COMPARTMENT - VISCERA
SAYAAHH!
PHARYNX
1) Larynx & Esophagus open into pharynx
2) Pharynx - a tube of muscles & fascia that opens to nasal and oral cavities
Nose
Nasal Cavity
Oral cavity
Larynx
Trachea
Pharynx
Esophagus
ANTERIOR COMPARTMENT -VISCERA
HYOID BONE- parts: body, greater & lesser horns – All Infrahyoid & Suprahyoid attach to Body of Hyoid (except Sternothyroid-> thyroid cartilage)
Palpable in neck
BODY
LESSERHORNS
GREATERHORNS
Hyoid means"U" shaped
HYOID BONE
Hyoid- means "U" shaped
Hyoid Bone –attached to larynx, pharynx & tongue; free floating; attached by ligaments and moved by muscles
Pharynx
esophagustrachea
ANTERIOR COMPARTMENT - moveable, changesshape in swallowing, speech
- muscles that move hyoid bone move larynx & tongue, for Swallowing, Talking
Hyoid Bone
Larynx
HYOID BONE
TONGUE
Lateral Compartment-lateral and posterior to pharynx
Contained in Carotid Sheath
1) Common and Internal Carotid arteries; 2) Int. jugularvein, 3) Vagus nerve
3. LATERAL COMPARTMENT - CAROTID SHEATH
OUTLINEII. MUSCLES
III. NERVES
IV. ARTERIES
V. VEINS
VI. FASCIA
VII. LYMPHATICS
II. MUSCLES OF NECK
A. MUSCLES OF NECK - NOT ATTACHED TO HYOID -move head & neck
1. STERNO-CLEIDOMASTOID
0 - Two heads 1) manubrium of sternum 2) clavicle- medial 1/3
I - mastoid process of temporal bone
Act - bilateral - flex head unilateral rotate head, face to directed opposite side
Inn - CN XI Accessory n.TORTICOLLIS –Contracture ofSternocleidomastoid
2. SCALENUS ANTERIOR AND SCALENUS MEDIUS
O - vertebrae-trans processes upper cervical
I - rib 1
A - flex neck & elevate rib 1
Inn - ventral rami of cervical spinal nerves
MUSCLES OF NECK - NOT ATTACHED TO HYOID
THESE MUSCLES ARE IMPORTANT LANDMARKS IN NECK
1. OMOHYOID (omo = greek for shoulder) - Two bellies -Inf. Belly- Scapula- medial to suprascapular notch
B. INFRAHYOID MUSCLES - all depress hyoid
2. STERNOHYOID O- Manubrium & clavicle
1. OMOHYOIDintermediate tendon to clavicle, rib 1; Sup. belly to hyoid
4. THYROHYOID - O -thyroid cartilage; also elevates larynx
3. STERNOTHYROID --O - manubrium I -thyroid cartilage; also depresses larynx
INFRAHYOID MUSCLES - all depress hyoid
deeperNOSE
SUPRAHYOID MUSCLES - all elevate hyoid
1. DIGASTRIC - two bellies / two cranial nerves -insert to hyoid via intermediate tendon
Post Belly-Temp. Bone, mastoid notch (medial to mastoid process)
Inn - CN VII
Ant. Belly-Mandible
Inn- CN V
Act- Depress mandible;
- MAJOR EFFECT is to OPEN Mouth
SUPRAHYOID MUSCLES - all elevate hyoid
NOSE
2. STYLOHYOID
O-styloid process of temp bone
tendon splits to surround digastric tendon
Inn - CN VII
SUPRAHYOID MUSCLES - all elevate hyoid
SUPRAHYOID MUSCLES - all elevate hyoid3. MYLOHYOID - forms muscular floor of mouth
O - mylohyoid line on inner side of mandible
Act - Elevates floor of mouth in swallowing
Inn - CN V - from V3
SUPRAHYOID MUSCLES - all elevate hyoid
4. GENIOHYOID -O - inner side of mandibleabove mylohyoid
A - Elevates hyoidand draws forward
Inn - C1 branchhitch-hiking withHypoglossal nerve (CN XII)
from C2-C4 ventral primary rami
III. NERVES OF NECK
A. CERVICAL PLEXUS
emerge from post border of sternocleidomastoid m.
1) Lesser OccipitalC2 behind ear
4) Supraclavicular -C3, C4 lower neck & shoulder
2) Great Auricular -(C2, C3) skin over parotid, inf. to ear
3) Transverse Cervical - C2, C3 ant. neck
A. CERVICAL PLEXUSNOSE
CERVICAL PLEXUS
NOSE
B. ANSA CERVICALIS- fibers from C1 join Hypoglossal Nerve (XII)
- some leave & join fibers of C2 & C3 to form ANSA (loop) Cervicalis
- other fibers continue with XII to innervate Thyrohyoid & Geniohyoid
(Looks like XII innervates neck muscles; actually C1-C3 do)
CN XII Receives hitchhiking fibers
ANSA CERVICALIS
At root of neck-passes to arm -becomes Axillary a. ( rib 1)- Scalenus Anteriormuscle divides Subclavian into 3 parts
A. SUBCLAVIAN ARTERY
SUBCLAVIAN A.
IV. ARTERIES OF HEAD AND NECK
Part 1- medial to scal. ant,
1) Vertebral a. 2) Int. thoracic a. 3) Thyrocervical trunk: branches -
Part 2- post to scal. ant.
1) Costocervical trunk - branches a) Superior intercostal a. first two int spaces; b) Deep cervical a. - deep neck
Part 3 - lat to scalenus ant. No Branches
SUBCLAVIAN ARTERY - divided into 3 parts by scalenus ant. muscle
a) Inf. thyroid b) Trans. cervical c) Suprascapular
Sterno-cleidomastoid
NOSE
Transverse cervical artery
Supra-scapular artery
Scalenus Ant. M.
Phrenic n.
4. FACIAL A- BELOW THEN ON SURFACE OF MANDIBLE
3. LINGUAL A-TONGUE
2. ASCENDING PHARYNGEAL A-ASCENDS TO PHARYNX
1. SUPERIOR THYROID A-DESCENDS TO THYROID
5. OCCIPITAL A-POST SCALP
6. POST. AURICULAR A-POST TO EAR
B. EXTERNAL CAROTID ARTERY
Superficial temporal-scalp & temporalis
Post auricular- post. ear & scalp
Occipital- post. scalp
Ascending pharyngeal-pharynx
Lingual- tongue
Superior thyroid- br. is Sup laryngeal
Maxillary
EXTERNAL CAROTID ARTERY
Facial
Reflect sterno-cleidomastoid
Common carotid divides -> int & ext carotid at upper border thyroid cartilage
EXTERNAL CAROTID ARTERY
Post side Ant side
SUP. THYROID
LINGUAL
FACIAL
OCCIPITAL
POST.AURICULAR
SUP. TEMPORAL
MAXILLARY
1. Superficial Temporal & Maxillary vv. form Retromandibular V. (RM)
2. Retromand. V. Divides Ant. (AD) and Post. (PD) divisions
3. Ant. Division joins Facial V. to form Common Facial V. -> Int. jugular V.
4. Post. Division joins Post. Auricular V. to form External Jugular V-> Subclavian V.
5. Ant. Jugular from veins below mandible -> Ext. Jugular above clavicle
Sup. Temp.
Max
Post. Auricular
External Jugular
Common facial
Facial
Ant jug
V. VEINS OF NECK
RMAD
PD
VEINS OF NECK
Pattern of Venous Drainage
A. Superficial fascia:
- connective tissue below dermis - completely surrounds neck -thin and hard to demonstrate - contains Platysma & Superficial veins
VI. FASCIA OF NECK
B. Deep Cervical fascia- one layer surrounds neck, other layers form tubes (names poorly chosen)
2. Prevertebral Layer
1. Investing layer
4. Carotid sheath
3. Pre-tracheal layer
FASCIA OF NECK
1. Investing layer of deep cervical fascia- surrounds neck, splits around sternocleid., trap, supra & infrahyoid 2. Prevertebral Layer- surrounds vert. column & muscles back of neck, prevertebral, lateral vertebral and suboccipital m.3. Pretracheal Layer- surrounds
trachea, esophag. & thyroid continues to mediastinum 4. Carotid Sheath- surrounds common & int carotid, int jugular and X (not: Symp. Chain) Retropharyngeal Space- between PreTrach & Pre Vert layers -infection from head (tonsillitis) can spread to mediastinum
Pretracheal layer
Prevertebral layer
Carotid Sheath
NOSE
FASCIA OF NECK
RETROPHARYNGEAL ABSCESS
Infection in retropharyngealspace can spread unimpededto mediastinum
FASCIA OF NECK
three groups (two arranged as rings; drain to chain)
A. Superficial Ring; Submental, Submandibular, Buccal, Parotid, Retro-auricular & Occipital nodes
B. Deep Ring: Pretracheal, Retropharyngeal nodes
C. Deep cervical chain-along Internal Jugular vein; receive lymph from all above nodes
D. Jugular lymph trunk - to Right lymphatic duct or Thoracic duct
VII. LYMPHATICS OF HEAD AND NECK
SMenSMan
B
PRA
O
PT
DeepCerv.Chain
RP