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