Clinical Anatomy of the
Neck
1
Objectives:
At the end of this lect. Students should be able to
describe :
1. Triangles of the neck
2.The subcutaneous tissue nerves, veins of the neck,
3.The main anatomical potential space in the neck
which lead to Spread Infections to the mediastinum.
4.Three major fascial compartments of the neck
Where the viscera of the neck are located.
5. Major blood vessels of the neck .
6. Lymphatic drainage system in Neck.
The Neck
• Anteriorly
lies between lower margin of mandible above &
suprasternal notch & upper border of clavicle below.
posteriorly
• Superior Nuchal line to intervertebral disc C7-T1.
*Visceral compartment anteriorly
*Vertebral compartment posteriorly
*Vascular compartments on each side laterally
Landmarks of the neck
• Sternocleidomastoid
• Suprasternal fossa
• Greater supraclaviclar fossa
• Hyoid bone
• Thyroid cartilage
• Cricoid cartilage
Hyoid bone
Hyoid bone…
…..Is a U-shaped bone consisting of
a median body, lesser horns (cornua) laterally, …………. paired , greater horns (cornua) posteriorly……… paired
1. Body
Provides attachments for :
Geniohyoid muscle,
mylohyoid, muscle
GMOS
Omohyoid muscle,
sternohyoid muscle.
2. Greater horn
Provides attachments for :
middle constrictor,
hyoglossus,
digastric (anterior and posterior) bellies,
stylohyoid,
thyrohyoid muscle.
3. Lesser horn
Provides attachment for :
stylohyoid ligament, •
which runs from styloid process to lesser horn
Skin of Neck
lines of cleavage of skin are constant
run …..horizontally …..around neck.
an incision :
along a cleavage line will heal as a narrow scar,
crosses lines will heal as a wide or heaped-up scar.
The natural line of cleavage of the skin are constant and
run almost horizontally around the neck
Platysma:
flat plate is a broad, thin sheet of muscle in subcutaneous tissue of neck
is supplied by cervical branch of CN VII.
Its fibers arise in deep fascia covering superior parts of deltoid & pectoralis major
muscles
sweep superomedially over clavicle to inferior border of mandible.
anterior borders of the two muscles decussate over chin, blend with facial
muscles.
Inferiorly, fibers diverge, leaving a gap anterior to larynx & trachea
Function of Palstysma:
tenses skin,
producing vertical skin ridges
releasing pressure on superficial veins.
حالقة
use in shaving
in a grimace.
depress the mandible and draw corners of mouth
inferiorly
Acting its inferior attachment
convey tension or stress.
Deep Cervical Fascia:
support :
viscera (thyroid gland),
muscles,
vessels, &
deep lymph nodes.
condenses around : ……… to form carotid sheath
form natural cleavage planes
tissues may be separated during surgery,
limit the spread of abscesses (collections of pus)
afford slipperiness
allows structures in neck to move and pass over one another without difficulty,
swallowing and turning the head and neck.
Carotid Sheath
is a tubular fascial investment
extends from cranial base to root of neck.
blends :
anteriorly with investing and pretracheal layers
posteriorly with prevertebral layer
contains :
common and internal carotid arteries,
internal jugular vein,
vagus nerve (CN X),
deep cervical lymph nodes,
carotid sinus .
sympathetic nerve fibers (carotid periarterial plexuses).
carotid sheath and pretracheal fascia communicate freely with:
mediastinum of thorax inferiorly &
cranial cavity superiorly.
represent potential pathways for spread of infection and extravasated blood.
A. The posterior triangle:
subdivided by the inferior belly of the
Omohyoid muscle into an
occipital
supraclavicular triangles.
The roof:
the skin and deep cervical fascia.
The floor:
the prevertebral fascia
The content:
Occipital lymph nodes, accessory
nerve, greater auricular nerve and the
cervical plexus.
B. Anterior triangle
Roof:……formed by:
• platysma
• investing layer of deep cervical fascia.
Is further divided by :
omohyoid superior belly
digastric anterior and posterior bellies
into :
digastric (submandibular),
Submental (suprahyoid),
Carotid triangle
muscular (inferior carotid) triangles.
Nerves in the posterior triangle
1-Cervical plexus 2-Brachial plexus 3- spinal root of
accessory nerve (11th
cranial nerve )
1- four muscular branches Roots , trunks and their branches
1- dorsal scapular nerve –c5(nerve to It is the most important
2- four cutaneous branches rhomboids )
2- nerve to subclavius – c5 &c6
structure in the occipital
3- nerve to serratus anterior –c5,6 &7 triangle
Suprascapular nerve –c5&6
A. (CN XI) Accessory nerve
Is formed by union of :
cranial & spinal roots. •
cranial roots :
• arise from medulla oblongata below roots of vagus.
spinal roots :
arise from lateral aspect of cervical segment of spinal cord
between C1 – C5
unites to form a trunk
ascends between dorsal & ventral roots of spinal nerves in vertebral canal
passes through foramen magnum.
Has both spinal and cranial portions,
traverse jugular foramen, they interchange fibers.
cranial portion
contains motor fibers .. join vagus nerve
innervate soft palate, pharyngeal constrictors, & larynx.
spinal portion
innervates sternocleidomastoid & trapezius muscles.
Lies on levator scapulae in posterior cervical triangle
passes deep to trapezius.
B. Cervical plexus
Is formed by ventral primary rami of C1 to C4.
1. Cutaneous branches
a- Lesser occipital nerve (C2)
Ascends along posterior border of sternocleidomastoid to scalp •
behind auricle. •
b- Great auricular nerve (C2-C3)
Ascends on sternocleidomastoid •
innervate skin behind auricle & on parotid gland. •
C- Transverse cervical nerve (C2-C3)
Turns around posterior border of sternocleidomastoid •
innervates skin of anterior cervical triangle. •
D-Supraclavicular nerve (C3-C4)
Emerges as a common trunk from under sternocleidomastoid
divides into anterior, middle, & lateral branches to skin over clavicle &shoulder.
2. Motor branches
Ansa cervicalis………………Is a nerve loop
formed by union of :
superior root (C1) descendens hypoglossi
inferior root (C2--C3; descendens cervicalis.
Lies superficial to carotid sheath
in anterior cervical triangle.
Innervates infrahyoid (strap) muscles:
omohyoid,
sternohyoid,
sternothyroid muscles,
with exception of thyrohyoid muscle,
innervated by C1 via hypoglossal N.
3. Phrenic nerve (C3-C5)
Arises from chiefly from 4th cervical nerve;
contains :
motor,
sensory,
sympathetic nerve fibers;
Provides:
motor supply to diaphragm
sensation to its central part.
• Descends on anterior surface of anterior scalene muscle
• under cover of sternocleidomastoid muscle.
• Passes between subclavian artery & vein at root of neck
• enters thorax by crossing in front of origin of internal thoracic artery,
• it joins pericardiacophrenic branch of this artery.
• Passes anterior to root of lung between mediastinal
pleura & fibrous pericardium
• supply sensory fibers to these structures.
longus capitis and cervicis or colli, sternocleidomastoid, trapezius,
levator scapulae, scalene muscles.
Accessory phrenic nerve (C5)
arises as a contribution of :
C5 to phrenic nerve or
a branch of nerve to subclavius (C5),
descends lateral to phrenic nerve,
enters thorax by passing posterior to subclavian vein,
joins phrenic nerve below first rib to supply diaphragm.
Main Arteries and
Veins of Neck
Superficial Veins
External Jugular Vein •
The external jugular vein begins just behind the angle of the mandible by the union of the •
posterior auricular vein with the posterior division of the retromandibular vein
Visibility of the External Jugular Vein •
The external jugular vein is less obvious in children and women
because their subcutaneous tissue tends to be thicker than the tissue of men
The External Jugular Vein as a Venous Manometer •
The external jugular vein serves as a useful venous manometer
External Jugular Vein Catheterization •
The external jugular vein can be used for catheterization, but the
presence of valves or tortuosity may make the passage of the catheter difficult.
Carotid Sinus
At its point of division, the common carotid artery
shows a localized dilatation, called carotid sinus
It serves as a reflex pressoreceptor mechanism
A rise in blood pressure causes a slowing of
the heart rate and vasodilatation of the arterioles
Carotid Body
It is a small structure lies posterior to the point of bifurcation
of the common carotid artery
It is innervated by glossopharyngeal nerve
It serves as a chemoreceptor
Sensitive to excess carbon dioxide and reduced
oxygen tension in the blood
Stimulus reflexly produces a rise in blood pressure
and heart rate and increase in respiratory movements
Clinical application
• Carotid Sinus Massage: initial
treatment of hemodynamically
stable paroxysmal
supraventricular tachycardia
• Cervical metastasis --- removal en
block of the internal jugular vein ,
the fascia, lymph nodes and
submandibular salivary gland
• (removal of all the lymph tissues
on the affected side of the neck)
Radical or Modified Radical Neck
Dissection.
LYMPH
• What is lymph?
Tissue fluid (interstitial fluid) that enters
the lymphatic vessels
FORMATION AND TRANSPORT
OF TISSUE FLUID
LYMPHATIC SYSTEM
Essentially a
What is lymph? drainage system
accessory to venous
*Tissue fluid system
(interstitial fluid)
that enters the
lymphatic vessels larger particles that
escape into tissue fluid can
only be removed via
lymphatic system
Lymph pathway :
• Deep cervical lymph nodes -------
--efferent lymph vessels---------
jugular lymph trunk----- :
• Left side----Thoracic duct -------
at the junction of the subclavian
and internal jugular veins
• Right side-------Right lymphatic
duct ------ venous system at the
junction between the subclavian
and internal jugular veins
LYMPH TRUNKS
right and left jugular trunks
right and left subclavian trunks
right and left bronchomediastinal
trunks
right and left lumbar trunks
intestinal trunk
LYMPHATIC DUCTS
24-
Right lymphatic duct
69
Formed by union of right
jugular, subclavian, and
bronchomediastinal trunks
Ends by entering the right
venous angle
LYMPHATIC DUCTS
Thoracic duct
Begins in front of L1 as a
dilated sac, the cisterna chyli ,
formed by left and right
lumbar trunks and intestinal
trunk
Enter thoracic cavity &
ascends
Travels upward, veering to
the left at the level of T5
THORACIC DUCT
71
At the root of the neck, it
turns laterally
arches forwards and
descends to enter the left
venous angle
before termination, it
receives the left jugular,
Subclavian and broncho-
mediastinal trunk
DRAINAGE PATTERN
RIGHT LYMPHATIC DUCT -
Receives lymph from right
half of head, neck, thorax
and right upper limb, right
lung, right side of heart, right
surface of liver
THORACIC DUCT - Drains
lymph from lower limbs,
pelvic cavity, abdominal
cavity, left side of thorax,
and left side of the head,
neck and left upper limb
Deep Cervical Lymph Nodes
VI 👉 Anterior visceral
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