Neck

Front 1

Pharyngeal Arches

Back 1

Front 2

Muscles: Superficial

Back 2

(1) Platysma:

• IN: CN VII

• A: Tenses skin of neck, depresses/wrinkles lower face

(2) Sternocleiodmastoid:

• IN: spinal portion of CN XI

• A: bilaterally extends; unilaterally draws chin up and flexes to same side

(3) Trapezius (Superior Portion):

• IN: spinal portion of CN XI

• A: Draws scapula obliquely upward and rotates glenoid cavity inferiorly

(4) Levator Scapulae:

• IN: C3-C5 anterior rami

• A: scapular movements

Front 3

Muscles: Suprahyoid

Back 3

• All insert into hyoid bone

(1) Geniohyoid:

o O: Inferior mental spine of mandible

o IN: Anterior ramus of C1

(2) Mylohyoid:

o O: Mylohyoid line

o IN: Mylohyoid n. (CN V3)

(3) Digastric:

o O: Mandible (anterior) + temporal bone (posterior)

o IN: Mylohyoid n. (anterior) + CN VII (posterior)(4) Stylohyoid:

o O: Styloid process

o IN: CN VII

Front 4

Muscles: Infrahyoid

Back 4

• (1) – (3) innervated via ANSA CERVICALIS

• All insert into hyoid unless stated otherwise

(1) Omohyoid:

o O: intermediate tendon (superior) + superiorborder of scapula (inferior)

(2) Sternohyoid:

o O: posterior surface of manubrium

(3) Sternothyroid:

o O: posterior surface of manubrium

o I: oblique line of thyroid cartilage

(4) Thyrohyoid:

o O: oblique of thyroid cartilage

o IN: anterior ramus of C1

Front 5

Muscles: Prevertebral

Back 5

Front 6

Thoracic Duct

Back 6

Right lymphatic ductdoesn’t travel entirethorax

Front 7

Arterial Blood Supply

Back 7

• Brachiocephalic Trunk: suppliesR. side of bodyo R. Subclavian A.

o R. Common Carotid: Bifurcates toR. external and internal-Carotid Body + Sinus

• L. Common Carotid A.

• L. Subclavian A.

Carotid Body: chemoreceptors (CN XI & X)Carotid Sinus: baroceptors (CN XI)

Front 8

Carotid body and sinus

Back 8

• Both located atbifurcation

• Carotid Sinus Swellingextends to ICA*

Front 9

Arterial Blood Supply

Back 9

External Carotid

• Gives 8 branches to theneck and is OUTSIDEthe skull

• Pneumonic:

o SALFOPMS

Front 10

Arterial Branches: R. Subclavian A.

Back 10

• Passes throughINTERSCALENE triangle

• Mnemonic: ICTV (D)

o Vertebral A., InternalThoracic., ThyrocervicalTrunk, Costal Cervical, DorsalScapular A (Sometimespresent*)

Front 11

Arterial Blood Supply: Branches of CCT and TCT (shown)

Back 11

• Costal Cervical Trunk Branches:

o deep cervical a.

o supremeintercostal a.

• Thyrocercival Trunk: ISAT on the trunk

o Inferior Thyroid A.

o Suprascapular A.

o Ascending Cervical A.

Note: travels with Phrenic N.

o Transverse Cervical A.

Front 12

Venous Drainage:

Back 12

• Maxillary V. + Superficialtemporal = RetromandibularV.

• Posterior Auricular V. +Posterior Retromandibular V.= EJV

• Facial V. + AnteriorRetromandibular V. =Common Facial (drains intoIJV)

• EJV drains to suclavian V.which drains tobrachiocephalic V.

Front 13

Venous Drainage: IJV

Back 13

• Drains into Brachiocephalic V.

• Mnemonic: Medical School LetsFunny People In

o Middle Thyroid V.

o Superior Thyroid V.

o Lingual V.

o Facial V. (joins anterior retromandibular)

o Pharygneal V.

o Infrapetrosal V.

• Note: Inferior thyroid V. drainsdirectly into Brachiocephalic V.

Front 14

Innervation: Cervical Plexus (C1-C4)

Back 14

LGTS

- Phrenic nerve: C3-C5 shared with brachial plexus; both motor and sensory --> diaphragm

Front 15

Innervation: Cervical Plexus (C1-C4)

Back 15

note the phrenic nerve

Front 16

Innervation: Cranial Nerves: Vagus Nerve (X):

Back 16

• Sensory: thoracic and abdominal viscera,muscosa of larynx/pharynx, caro=d body

• Motor: muscles of pharynx/larnyx

• Visceral Motor: regulates HR, BR, digestiveactivity

• Superior Laryngeal Br.:

o Internal = sensory

o External = motor

• Recurrent Laryngeal Br.: MIXED

o L. Side: loops around arch of aorta

o R. Side: loops around subclavian a.

Front 17

Innervation: Cranial Nerves: Accessory Nerve (CN XI)

Back 17

MOTOR

• 2 components – SPINAL and CRANIAL

• Pathway: exits via jugular foramen, descends down carotid sheath, and travelsthrough POSTERIOR triangle

• Supplies: SCM and TRAPEZIUS

Front 18

Innervation: Cranial Nerves: Hypoglossal Nerve (CN XII)

Back 18

MOTOR

• Pathway: exits hypoglossal canal, momentarily in the carotid sheath, wrapsaround external carotid artery and travels to oral cavity

• Supplies: 7/8 glossal muscles EXCEPT PLATOGLOSSUS

Front 19

Triangles of Neck

Back 19

Front 20

Triangles diagram

Back 20

Front 21

Triangles of Neck: Anterior: Bounded by SCM, midline of the neck, mandible

Back 21

(1) Submandibular (Gastric) Triangle:

• Bounded by: mandible, post and ant digastric

• Contains: submandibular gland, facial artery, vein and nerve (and branches)

(2) Carotid Triangle:

• Bounded by: SCM, superior omohyoid, and posterior digastric

• Contains: common carotid a, external and internal a, internal jugular, superiorroot of ansa cervicalis, internal laryngeal nerve and nerve to thyrohyoid C1,hypoglossal n, internal jugular vein, facial vein, and superior thyroid artery

(3) Muscular Triangle:

• Bounded by sternocleidomastoid, superior omohyoid and sternohyoid

(4) Submental Triangle:

• Bounded by the anterior bellies of the digastric, hyoid bone and mandible

Front 22

Triangles of Neck: Posterior: Bounded by SCM, trapezius, and clavicle

Back 22

• Bounded by the sternocleidomastoid, trapezius, and clavicle

• Contains: external jugular, cervical plexus, accessory nerve, brachial plexus,transverse cervical artery and vein, phrenic nerve, accessory phrenic nerve,surprascapular artery and vein, subclavian artery and vein

• Muscles that form the floor: levator scapulae, scalene (posterior, middleand anterior)

(1) Supraclavicular (omoclavicular and subclavian) Triangle:

o Bounded by the inferior belly of the omohyoid, clavicle and sternocleidomastoid

(2) Occipital Triangle:

o Bounded by the inferior belly of the omohyoid, trapezius and sternocleidomastoid

Front 23

Fascia and Spaces

Back 23

(1) Prevertebral Fascia:

• Splits into ANTERIOR (ALAR) and POSTERIOR layer

• DANGER ZONE is located between these regions

(2) Pretracheal Fascia:

• Muscular portion: holds the infrahyoid muscles• Visceral portion: holds the thyroid gland, trachea, esophagus and pharynx

o Continuous with the BUCCOPHARYNGEAL FASCIA

(3) Carotid Sheath:

• Common carotid artery, internal carotid artery, vagus nerve, internal jugular vein

• AT the very base of the skull: contains CN IX, X, XI and XII but they eventuallyleave it