Horizontal Section Through Neck

I. OVERVIEW OF NECK - neck is compartmentalized
LAT.
POST.
Plane of section
ANT.
HORIZONTAL SECTION THROUGH NECK
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

BACK
+ SUBOCCIP
MUSCLES
Post side - Deep
Muscles (like
back)- extensor
& Suboccipital
Muscles
1. POSTERIOR COMPARTMENT
- muscles move head and neck
SCALENE
MUSCLES
Lateral side -
Scalene
muscles - flex
neck laterally
PRE-
VERTEBRAL
MUSCLES
Anterior side -
Prevertebral Muscles -
directly anterior to
vertebrae - flex head &
neck

2. ANTERIOR COMPARTMENT - VISCERA
Esophagus
Trachea
In thorax,
trachea is
anterior to
esophagus

ANTERIOR COMPARTMENT - VISCERA
Anterior
Compartment -
Larynx is part of
upper end of
respiratory systemspecialized
for
sound production;
also acts as
‘sphincter’ of
respiratory system-
Thyroid cartilage is
Adam's apple
Larynx
Trachea

SAY
AAHH!
PHARYNX

Nasal
Cavity
Oral
cavity
Nose
Larynx
Trachea
Pharynx
ANTERIOR
COMPARTMENT -
VISCERA
Esophagus
1) Larynx &
Esophagus
open into
pharynx
2) Pharynx - a
tube of
muscles &
fascia that
opens to nasal
and oral
cavities

HYOID BONE- parts: body, greater & lesser horns – All
Infrahyoid & Suprahyoid attach to Body of Hyoid
(except Sternothyroid-> thyroid cartilage)
Palpable
in neck
Hyoid means
"U" shaped
GREATER
HORNS
LESSER
HORNS
BODY

ANTERIOR COMPARTMENT - moveable, changes
shape in swallowing, speech
Hyoid Bone –
attached to
larynx, pharynx &
tongue; free
floating; attached
by ligaments and
moved by
muscles
trachea
Hyoid- means "U"
shaped
HYOID BONE
Pharynx
esophagus

TONGUE
Hyoid
Bone
Larynx
HYOID BONE
- muscles that
move hyoid
bone move
larynx &
tongue, for
Swallowing,
Talking

3. LATERAL COMPARTMENT - CAROTID SHEATH
Lateral Compartmentlateral
and posterior to
pharynx
Contained in Carotid
Sheath
1) Common and
Internal Carotid
arteries; 2) Int. jugular
vein, 3) Vagus nerve

OUTLINE
II. 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 of
Sternocleidomastoid

MUSCLES OF NECK - NOT ATTACHED TO HYOID
2. SCALENUS
ANTERIOR AND
SCALENUS MEDIUS
O - vertebraetrans
processes
upper cervical
I - rib 1
A - flex neck &
elevate rib 1
Inn - ventral
rami of cervical
spinal nerves
THESE MUSCLES ARE IMPORTANT
LANDMARKS IN NECK

B. INFRAHYOID MUSCLES - all depress hyoid
1. OMOHYOID (omo = greek
for shoulder) - Two bellies -
Inf. Belly- Scapula- medial to
suprascapular notch

INFRAHYOID MUSCLES - all depress hyoid
NOSE
2. STERNOHYOID
O- Manubrium &
clavicle
1. OMOHYOID
intermediate
tendon to
clavicle, rib 1;
Sup. belly to
hyoid
deeper
4. THYROHYOID -O -
thyroid cartilage; also
elevates larynx
3. STERNOTHYROID --
O - manubrium I -
thyroid cartilage; also
depresses larynx

SUPRAHYOID MUSCLES - all elevate hyoid

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
Act- Depress mandible;
- MAJOR EFFECT is to OPEN Mouth
NOSE
Ant. Belly-
Mandible
Inn- CN V

SUPRAHYOID MUSCLES - all elevate hyoid
2. STYLOHYOID
O-styloid
process of temp
bone
tendon splits to
surround
digastric tendon
Inn - CN VII

SUPRAHYOID MUSCLES - all elevate hyoid
3. 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
mandible
above mylohyoid
A - Elevates hyoid
and draws forward
Inn - C1 branch
hitch-hiking with
Hypoglossal nerve
(CN XII)

III. NERVES OF NECK
A. CERVICAL PLEXUS
from C2-C4
ventral primary
rami

1) Lesser Occipital
C2 behind ear
4) Supraclavicular -
C3, C4 lower neck &
shoulder
A. CERVICAL PLEXUS NOSE
2) Great Auricular -
(C2, C3) skin over
parotid, inf. to ear
3) Transverse
Cervical -C2, C3
ant. neck
emerge from post
border of
sternocleidomastoid
m.

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

IV. ARTERIES OF HEAD AND NECK
SUBCLAVIAN A.
A. SUBCLAVIAN
ARTERY
At root of neckpasses
to arm -
becomes Axillary a.
( rib 1)
- Scalenus Anterior
muscle divides
Subclavian into 3
parts

SUBCLAVIAN ARTERY - divided into 3 parts by
scalenus ant. muscle
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
Part 1- medial to
scal. ant,
1) Vertebral a.
2) Int. thoracic a.
3) Thyrocervical
trunk: branches -
a) Inf. thyroid
b) Trans. cervical
c) Suprascapular

NOSE
Sternocleidomastoid

Transverse
cervical
artery
Suprascapular
artery
Phrenic n.
Scalenus Ant.
M.

B. EXTERNAL CAROTID ARTERY
5. OCCIPITAL A-
POST SCALP
6. POST.
AURICULAR A-
POST TO EAR
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

Superficial temporalscalp
& temporalis
Post auricular- post. ear &
scalp
Occipital- post.
scalp
EXTERNAL CAROTID ARTERY
Ascending pharyngealpharynx
Maxillary
Facial
Lingual- tongue
Superior thyroid- br. is Sup
laryngeal

EXTERNAL CAROTID ARTERY
Reflect sternocleidomastoid
Common
carotid divides
-> int & ext
carotid at upper
border thyroid
cartilage

Post side
POST.
AURICULAR
OCCIPITAL
Ant side
SUP.
TEMPORAL
MAXILLARY
FACIAL
LINGUAL
SUP.
THYROID

Post.
Auricular
External
Jugular
Sup.
Temp.
PD
V. VEINS OF NECK
RM
AD
Max
Common
facial
Ant
jug
Facial
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

Pattern of
Venous
Drainage
VEINS OF NECK

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
FASCIA OF NECK
1. Investing layer
4. Carotid
sheath
3. Pre-tracheal
layer

N
O
S
E
Carotid
Sheath
Prevertebral
layer
FASCIA OF NECK
Pretracheal
layer
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

RETROPHARYNGEAL ABSCESS
Infection in retropharyngeal
space can spread unimpeded
to mediastinum

FASCIA OF NECK

O
VII. LYMPHATICS OF HEAD AND NECK
RA
Deep
Cerv.
Chain
P
SMan
B
RP
SMen
PT
three groups (two arranged as
rings; drain to chain)
A. Superficial Ring;
Submental, Submandibular,
Buccal, Parotid, Retroauricular
& Occipital nodes
B. Deep Ring: Pretracheal,
Retropharyngeal nodes
C. Deep cervical chainalong
Internal Jugular vein;
receive lymph from all
above nodes
D. Jugular lymph trunk -to
Right lymphatic duct or
Thoracic duct