Neck Region

PA 481

Anterior Surface

Triangles at Surface

Hyoid

1. C3 level2. Suprahyoid muscles3. Infrahyoid muscles

Vertebral Column

Intervertebral disc

VertebraParts

C1 & C2

Cervical Vertebra

Typical Cervical Vertebra

Spinal Cord

• Receives and generates signals to body through the spinal nerves

Cord in Spinal Canal

Dorsal Root Ganglion

Denticulate Ligament

Posterior Median Sulcus

Posterior Root

Anterior Root

Spinal Nerve

Spinal Cord (X.S.)

Spinal Cord (x.s.)

Spinal Nerve Anatomy

Functional Arrangement of SC

Ascending and descending pathways

Ascending Pathways

Descending Pathways

Cervical Plexus

Serves neck and diaphragm

Brachial Plexus and pectoral nerves

Brachial Plexus

Innervates most of the arm and someof the body wall.

Spinal Cord Segments

• 4 segments: Cervical, Thoracic, Lumbar, and Sacral (only 1 coccygeal nerve)

• 31 pairs of spinal nerves

Cervical Segment

Neck Fascia

Prevertebral fascia

Alar fascia

Pretracheal fasciaInvesting fascia

Superficial fascia

Platysma

SCM

Trapezius

SCM and Trapezius

Cervical Triangles

Posterior Triangle Anterior Triangle

Posterior Triangle

Supraclavicular triangle

Occipital triangle

Superficial and Deep Posterior Triangle

Platysma

Nerve Point of Neck

Ext. jugular v.

SCM

Accessory n.

Prevertebral fascia

Brachial plexus

Scalenes

Phrenic n.

Splenius

Levator scapulae

Supraclavicular Triangle

Brachial Plexus

Subclavian vessels

SCM

Anterior Triangles

SubmentalCarotid

Submandibular

Muscular

Muscular Triangle

Muscles of Triangle

Sternohyoid

Sternothyroid

Thyrohyoid

Thyroid

Thyroid Location

Accessory Thyroid gland

Accessory thyroid along thyroglossal duct

Pyramidal lobe(50% of people have this lobe structure)

Thyroid Follicle

(follicular cells thyroxine)

Parafollicular cells calcitonin

T3 & T4 Formation and Secretion

T3 & T4

Control of Thyroxine Secretion

Short loop

Long loop

Thyroid Malfunction

• Hypothyroidism• Endemic goiters –due to iodine

deffeicency

• Cretinism – thyroxine in child results in growth (dwarf) and severe mental retardation

• Myxedema – thyroxine in adult, leads to swelling of tissues plus other symptoms

Cretinism

Thyroid Malfunction• Hyperthyroidism

• Toxic goiters (Graves disease) –Ab may stimulate thyroid without negative feedback control

• Exophthalmos –symptom present in many hyperthyroid patients

Parathyroid Location

Parathyroid

PTH Actions• Stimulates resorption of

bone Ca+ and PO4- in

blood

• Stimulates Ca+ absorption in intestine (active Vit. D3 necessary for Ca+ absorption)

• Stimulates Ca+ reabsorption and PO4

- excretion in kidney

• Stimulates Vit. D3 formation (skin) and activation (kidney)

• Vital for life

Thyroid cartilage

Cricoid cartilage

Epiglottis

Arytenoid cartilage

Laryngeal Cartilages

Hyoid

(posterior)

(anterior)

Voice Box

Vocal fold

Vestibular fold

Ventricle

CN X: supply to laryngeal muscles

Recurrent Laryngeal n.(motor to all other laryngeal muscles) –left side goes under aortic arch

External Laryngeal n.(motor to inf. Pharnygeal constrictor and the cricohyoid)

Internal Laryngeal n.(sensory & autonomic)

Inf. Vagal ganglion

Submental Triangle

Digastric

Mylohyoid

-contains submental lymph nodes

Carotid Triangle

Digastric (posterior belly)

SCM

Ansa cervicalis

Common carotid a.

Internal carotid a.

External carotid a.

IJV

Omohyoid

Ext. Carotid Branches

Common CarotidIJV

Int. carotid

Ext. carotid

Sup. Thyroid

FacialLingual

Occipital Post. Auricular

Maxillary

Superficial Temporal

Asc. Pharyngeal (not show)Ansa cervicalis

Hypoglossal n.

External carotid (isolated)

Occipital

Post. Auricular

Superficial Temporal

Maxillary

Sup. Thyroid

Facial

Lingual

Asc. Pharyngeal

Note: Internal carotid has NO branches before cranium generally. (8% of population, the internal gives rise to asc. pharyngeal a..)

Important branches:Maxillary gives rise to: -Middle Meningeal a. that supplies meninges and calvaria; enters through f. spinosum (rupture leads to epidural hemotoma)-Infraorbital a. may form anastamoses with supraorbital a (a branch of opthalmic from Int. carotid.) this can lead to an alternative path for blood if carotids blocked)

Carotid bodies

Sensors increase firing rate as BP falls

IJVSup. Bulb of IJV

Inf. Bulb of IJV

IJV

FacialSup. Thyroid

Lymph nodes of neck

Deep Cervical Lymph nodes(most located in carotid sheath)

Submandibular TriangleSubmandibular glands

Digastrics

Submandibular Lymph nodes

PharynxFunction: deglutitionMucosa: Str. SquamousMuscularis: Skeletal

Oro- and nasopharynxPharyngeal tonsil

Pharyngeal recess

Palatine bone

Soft palate

Uvula

Lingual Tonsil

Tubal tonsils (small holes)Pharyngotympanic (Eustachian) tube

Salpingopharyngeal fold

Tonsillar cleftPalatoglossal arch

Palatopharyngeal arch

Longitudinal pharyngeal muscles

Palatopharyngeus

Tonsils

PharyngealTonsil

Pharyngeal Constrictors

Superior

Middle

Inferior

Peristalsis

Deglutition (Swallowing)

Fluid Drinking

Deglutition (cont’d)

Deglutition (cont’d)

Laryngopharynx

Epiglottis

Piriform recess