Download MBBS Deep Fascia of the Neck Lecture PPT

Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Deep Fascia of the Neck Lecture PPT


? Pretracheal fascia
? This layer of deep cervical fascia covers the front

and sides of trachea, hence its name--pretracheal

fascia.

? It splits to enclose the thyroid gland forming its

capsule and is attached to the oblique line of

thyroid cartilage and to the arch of cricoid cartilage

anteriorly.

? Ligament of Berry is derived from this fascia and

connects the capsule of the lateral lobe of the

thyroid gland to the cricoid cartilage

? Tracing of the pretracheal fascia
? Horizontal tracing:
? It merges with the investing layer of deep cervical

fascia enclosing the sternocleidomastoid and the

anterior wall of the carotid sheath.

? Vertical tracing:
? It is attached to the hyoid bone and when traced

below, it enters the thorax in front of the trachea

and blends with the apex of the fibrous

pericardium.
? Prevertebral fascia
? It is extremely strong and lies in front of the

prevertebral muscles

? Tracing of the prevertebral fascia
? Horizontal tracing:
? It forms the fascial carpet of the posterior triangle.
? It also forms axillary sheath, which may extend up

to the elbow.

? Subclavian and axillary veins lie outside the sheath
? Vertical tracing:
? Traced aboveextends up to the base of the skull

to which it is attached.

? Traced below continues downwards and blends

with the anterior longitudinal ligament of the upper

thoracic vertebrae (T1 to T3).
Retropharyngeal space

? Anteriorly, the prevertebral layer of deep cervical

fascia is separated from posterior aspect of the

pharynx and its covering, buccopharyngeal fascia,

by a potential space called retropharyngeal space.

? The retropharyngeal space is continuous with the

parapharyngeal spaces at the sides of the pharynx.

? The retropharyngeal space is divided into two

lateral compartments (spaces of Gillette) by a

midline fibrous raphe.

? The space behind the prevertebral fascia and in

front of the vertebral bodies is called prevertebral

space.

SIDE OF THE NECK


Side of the Neck

? Quadrangular in shape.
? It is bounded
? Anteriorly anterior midline

of the neck

? Posteriorly anterior border

of the trapezius

? Superiorly lower border of

the body of the mandible and

a line extending from the

angle of the mandible to the

mastoid process

? Inferiorly clavicle.


Triangles on the side of the neck

? This quadrilateral area

is divided into large

anterior and posterior

triangles by the

sternocleidomastoid

muscle

? Which runs across this

area diagonally from

mastoid process to

the upper end of the

sternum.


Sternocleidomastoid Muscle

Origin

Sternal headarises by a rounded

tendon from the superolateral part

Of the front of the manubrium

sterni, below the suprasternal notch.

Clavicular head flat and

musculoaponeurotic. It arises from

the medial third of the superior

surface of the clavicle.

Insertion

by a thick tendon on the lateral

surface of the mastoid process and by

a thin aponeurosis into the lateral

half

of the superior nuchal line of the

occipital bone
? Arterial Supply
? The sternocleidomastoid is supplied by branches of

following arteries:

Upper part occipital and posterior auricular art.
Middle part superior thyroid artery.
Lower part suprascapular artery.
? Nerve Supply
? Supplied by the spinal accessory nerve.
? It is also supplied by the ventral rami of C2 and C3,

which are mostly sensory and carry proprioceptive

sensations from the muscle.
? Actions
? When muscle acting alone , it tilts the head towards

the shoulder on the same side and rotates the head

so that chin turns to the opposite side. This

movement occurs during an upward sideways glance.

? When muscles of both sides contract together they

draw the head forwards as in lifting the head from

the pillow or bending the head during eating food.

? If the head is fixed by prevertebral muscles, the two

sternocleidomastoid muscles act as accessory

muscles of respiration during forced inspiration.
Torticollis or wry neck

? Head is bent to one side and chin points to the opposite side.
? This occurs due to spasm of sternocleidomastoid and

trapezius muscles supplied by spinal accessory nerve.

? Spasmodic torticollis is characterized by repeated painful

contractions of the trapezius and sternocleidomastoid

muscles on one side. Caused by exposure to cold and

maladjustment of pillow during sleep.

? Reflex torticollis occurs due to irritation of spinal accessory

nerve caused by inflamed or suppurating lymph nodes.

? Congenital torticollis occurs due to birth injury to muscle.

Permanent torticollis may occur due to subsequent ischemic

contracture
POSTERIOR TRIANGLE

? It is the triangular space on the side of neck behind the

sternocleidomastoid muscle. Its apex is directed

upwards and backwards towards the mastoid process

and base downwards towards the clavicle.

? Boundaries
? Anterior: Posterior border of sternocleidomastoid

muscle.

? Posterior: Anterior border of trapezius muscle.
? Inferior (base): Superior aspect of middle third of the

clavicle.

? Superior (apex): Meeting point of sternocleidomastoid

and trapezius muscles at the superior nuchal line of the

occipital bone

? Roof
? Formed by investing layer of the deep cervical fascia
? superficial fascia overlying the roof contains platysma,

external jugular and posterior jugular veins, and

cutaneous nerves and vessels.

? Structures piercing the roof of the posterior triangle

are

1. Four cutaneous branches of cervical plexus

(a) Lesser occipital nerve (C2)

(b) Great auricular nerve (C2, C3)

(c) Transverse cervical nerve (C2, C3)

(d) Supraclavicular nerves (C3, C4).

2. External jugular vein

? Floor
? The floor of posterior triangle is muscular.
? Formed from above downwards by
1. Semispinalis capitis.
2. Splenius capitis.
3. Levator scapulae.
4. Scalenus medius.
5. First digitation of serratus anterior (sometimes).

? Fascial carpet of the posterior triangle
? The muscular floor of posterior triangle is covered

by prevertebral layer of deep cervical fascia, which

forms the fascial carpet of the floor of the

posterior triangle.

? It forms axillary sheath around subclavian artery

and brachial plexus travelling from the root of the

neck to the upper limb.

? The lower part of the posterior triangle is crossed

by inferior belly of omohyoid superficial to the

fascial carpet.

? Subdivisions
? The posterior triangle is subdivided into two

parts by the inferior belly of the omohyoid.

? (a) occipital triangle a upper larger part.
? (b) subclavian (supraclavicular) triangle small

lower part.

? These parts are so named because they contain

occipital and subclavian arteries, respectively.



? Contents
1. In the occipital triangle
(a) Spinal accessory nerve
(b) 3rd and 4th cervical nerves providing branches to
levator scapulae and trapezius muscles
(c) Dorsal scapular nerve (C5)
(d) Four cutaneous branches of cervical plexus (initial
parts)
(e) Superficial transverse cervical artery
(f) Occipital artery

2. In the subclavian(supraclavicular triangle)
(a) 3rd part of the subclavian artery
(b) Subclavian vein
(c) Terminal part of external jugular vein
(d) Trunks of brachial plexus
(e) Superficial (transverse) cervical, suprascapular,

and dorsal scapular arteries

(f) Lymph nodes
? All the important contents of the posterior triangle

lie deep to the fascial carpet of the floor

? except spinal accessory nerve, which lies just

underneath the roof.

? In operations on the posterior triangle all the

structures except spinal accessory nerve are safe,

provided fascial carpet of posterior triangle is left

intact.


Spinal accessory nerve

? This nerve emerges in the

posterior triangle by piercing

the posterior border of the

sternocleidomastoid (a little

above the middle of this

border).

? It is related to lymph nodes of

the upper deep cervical chain .

? The nerve running downwards

parallel to the fibres of levator

scapulae muscle to

? Disappear underneath to the

anterior border of trapezius and

supplies trapezius muscle.

? In the posterior triangle it is

adherent to the deep aspect of

the fascial roof of this triangle.


Four cutaneous branches of cervical plexus

? It emerge at the midpoint (just above)

of the posterior border of the

sternocleidomastoid by piercing the

deep cervical fascia.

(a)lesser occipital nerve
auricle and head behind the auricle.

(b) great auricular nerve
anterior and posterior branches.
skin on angle of the mandible

mastoid

region and auricle (lower part).

(c) transverse cervical nerve
ascending and descending br.
skin of the front of the neck.

(d) supraclavicular nerve
medial, intermediate, lateral

supraclavicular

skin on chest up to the 2nd rib, front of

the chest, deltoid muscle(upper half)
? Transverse cervical artery: branch of thyrocervical

trunk of the first part of subclavian artery.

? Suprascapular artery: branch of thyrocervical trunk

? Dorsal scapular artery: It arises from the third part

of the subclavian artery.

? Occipital artery: branch of external carotid artery

? Subclavian artery


Lymph nodes

? These are deep cervical lymph

nodes found at the following

sites in the posterior triangle:

(a) A chain of nodes along the

posterior border of

sternocleidomastoid.

(b) A chain of nodes along the

spinal accessory nerve.

(c) A few nodes in the apical

region of the triangle called

occipital lymph nodes.

(d) A group of supraclavicular

lymph nodes.

? These nodes lie superficial to

brachial plexus and subclavian

vessels.
Swelling in the posterior triangle

? Most common cause of swelling in the posterior

triangle is due to enlargement of lymph nodes.

? Supraclavicular lymph nodes are commonly

involved and enlarged in tuberculosis, Hodgkin's

disease, and malignant growth of breast, arm, and

chest.

? Left supraclavicular lymph nodes (Virchow's lymph

nodes) are commonly involved in metastasis from

cancer stomach, cancer testis, and cancer of other

abdominal organs.

? The biopsy of these lymph nodes is helpful in early

diagnosis of distant malignancies.

This post was last modified on 30 November 2021