? Pretracheal fascia
? This layer of deep cervical fascia covers the front
and sides of trachea, hence its name--pretracheal
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fascia.
? It splits to enclose the thyroid gland forming its
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capsule and is attached to the oblique line ofthyroid cartilage and to the arch of cricoid cartilage
anteriorly.
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? Ligament of Berry is derived from this fascia and
connects the capsule of the lateral lobe of the
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thyroid gland to the cricoid cartilage? Tracing of the pretracheal fascia
? Horizontal tracing:
? It merges with the investing layer of deep cervical
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fascia enclosing the sternocleidomastoid and the
anterior wall of the carotid sheath.
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? Vertical tracing:? It is attached to the hyoid bone and when traced
below, it enters the thorax in front of the trachea
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and blends with the apex of the fibrouspericardium.
? Prevertebral fascia
? It is extremely strong and lies in front of the
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prevertebral muscles
? Tracing of the prevertebral fascia
? Horizontal tracing:
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? It forms the fascial carpet of the posterior triangle.? It also forms axillary sheath, which may extend up
to the elbow.
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? Subclavian and axillary veins lie outside the sheath? Vertical tracing:
? Traced aboveextends up to the base of the skull
to which it is attached.
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? Traced below continues downwards and blends
with the anterior longitudinal ligament of the upper
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thoracic vertebrae (T1 to T3).Retropharyngeal space
? Anteriorly, the prevertebral layer of deep cervical
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fascia is separated from posterior aspect of thepharynx and its covering, buccopharyngeal fascia,
by a potential space called retropharyngeal space.
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? The retropharyngeal space is continuous with the
parapharyngeal spaces at the sides of the pharynx.
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? The retropharyngeal space is divided into twolateral compartments (spaces of Gillette) by a
midline fibrous raphe.
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? The space behind the prevertebral fascia and in
front of the vertebral bodies is called prevertebral
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space.SIDE OF THE NECK
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Side of the Neck? Quadrangular in shape.
? It is bounded
? Anteriorly anterior midline
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of the neck
? Posteriorly anterior border
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of the trapezius? Superiorly lower border of
the body of the mandible and
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a line extending from the
angle of the mandible to the
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mastoid process? Inferiorly clavicle.
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Triangles on the side of the neck? This quadrilateral area
is divided into large
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anterior and posterior
triangles by the
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sternocleidomastoidmuscle
? Which runs across this
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area diagonally from
mastoid process to
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the upper end of thesternum.
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Sternocleidomastoid MuscleOrigin
Sternal headarises by a rounded
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tendon from the superolateral part
Of the front of the manubrium
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sterni, below the suprasternal notch.Clavicular head flat and
musculoaponeurotic. It arises from
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the medial third of the superior
surface of the clavicle.
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Insertionby a thick tendon on the lateral
surface of the mastoid process and by
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a thin aponeurosis into the lateral
half
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of the superior nuchal line of theoccipital bone
? Arterial Supply
? The sternocleidomastoid is supplied by branches of
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following arteries:
Upper part occipital and posterior auricular art.
Middle part superior thyroid artery.
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Lower part suprascapular artery.? Nerve Supply
? Supplied by the spinal accessory nerve.
? It is also supplied by the ventral rami of C2 and C3,
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which are mostly sensory and carry proprioceptivesensations from the muscle.
? Actions
? When muscle acting alone , it tilts the head towards
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the shoulder on the same side and rotates the head
so that chin turns to the opposite side. This
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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
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the pillow or bending the head during eating food.
? If the head is fixed by prevertebral muscles, the two
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sternocleidomastoid muscles act as accessorymuscles of respiration during forced inspiration.
Torticollis or wry neck
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? 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.
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? Spasmodic torticollis is characterized by repeated painfulcontractions of the trapezius and sternocleidomastoid
muscles on one side. Caused by exposure to cold and
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maladjustment of pillow during sleep.
? Reflex torticollis occurs due to irritation of spinal accessory
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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
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contracture
POSTERIOR TRIANGLE
? It is the triangular space on the side of neck behind the
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sternocleidomastoid muscle. Its apex is directed
upwards and backwards towards the mastoid process
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and base downwards towards the clavicle.? Boundaries
? Anterior: Posterior border of sternocleidomastoid
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muscle.? Posterior: Anterior border of trapezius muscle.
? Inferior (base): Superior aspect of middle third of the
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clavicle.? Superior (apex): Meeting point of sternocleidomastoid
and trapezius muscles at the superior nuchal line of the
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occipital bone
? Roof
? Formed by investing layer of the deep cervical fascia
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? superficial fascia overlying the roof contains platysma,external jugular and posterior jugular veins, and
cutaneous nerves and vessels.
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? Structures piercing the roof of the posterior triangle
are
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1. Four cutaneous branches of cervical plexus(a) Lesser occipital nerve (C2)
(b) Great auricular nerve (C2, C3)
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(c) Transverse cervical nerve (C2, C3)
(d) Supraclavicular nerves (C3, C4).
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2. External jugular vein? Floor
? The floor of posterior triangle is muscular.
? Formed from above downwards by
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1. Semispinalis capitis.2. Splenius capitis.
3. Levator scapulae.
4. Scalenus medius.
5. First digitation of serratus anterior (sometimes).
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? Fascial carpet of the posterior triangle
? The muscular floor of posterior triangle is covered
by prevertebral layer of deep cervical fascia, which
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forms the fascial carpet of the floor of the
posterior triangle.
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? It forms axillary sheath around subclavian arteryand brachial plexus travelling from the root of the
neck to the upper limb.
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? The lower part of the posterior triangle is crossed
by inferior belly of omohyoid superficial to the
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fascial carpet.? Subdivisions
? The posterior triangle is subdivided into two
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parts by the inferior belly of the omohyoid.? (a) occipital triangle a upper larger part.
? (b) subclavian (supraclavicular) triangle small
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lower part.? These parts are so named because they contain
occipital and subclavian arteries, respectively.
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? Contents
1. In the occipital triangle
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(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
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parts)(e) Superficial transverse cervical artery
(f) Occipital artery
2. In the subclavian(supraclavicular triangle)
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(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,
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and dorsal scapular arteries
(f) Lymph nodes
? All the important contents of the posterior triangle
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lie deep to the fascial carpet of the floor
? except spinal accessory nerve, which lies just
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underneath the roof.? In operations on the posterior triangle all the
structures except spinal accessory nerve are safe,
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provided fascial carpet of posterior triangle is left
intact.
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Spinal accessory nerve
? This nerve emerges in the
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posterior triangle by piercingthe posterior border of the
sternocleidomastoid (a little
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above the middle of this
border).
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? It is related to lymph nodes ofthe upper deep cervical chain .
? The nerve running downwards
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parallel to the fibres of levator
scapulae muscle to
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? Disappear underneath to theanterior border of trapezius and
supplies trapezius muscle.
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? In the posterior triangle it is
adherent to the deep aspect of
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the fascial roof of this triangle.Four cutaneous branches of cervical plexus
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? It emerge at the midpoint (just above)of the posterior border of the
sternocleidomastoid by piercing the
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deep cervical fascia.
(a)lesser occipital nerve
auricle and head behind the auricle.
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(b) great auricular nerve
anterior and posterior branches.
skin on angle of the mandible
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mastoidregion and auricle (lower part).
(c) transverse cervical nerve
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ascending and descending br.skin of the front of the neck.
(d) supraclavicular nerve
medial, intermediate, lateral
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supraclavicular
skin on chest up to the 2nd rib, front of
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the chest, deltoid muscle(upper half)? Transverse cervical artery: branch of thyrocervical
trunk of the first part of subclavian artery.
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? Suprascapular artery: branch of thyrocervical trunk? Dorsal scapular artery: It arises from the third part
of the subclavian artery.
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? Occipital artery: branch of external carotid artery
? Subclavian artery
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Lymph nodes
? These are deep cervical lymph
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nodes found at the followingsites in the posterior triangle:
(a) A chain of nodes along the
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posterior border of
sternocleidomastoid.
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(b) A chain of nodes along thespinal accessory nerve.
(c) A few nodes in the apical
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region of the triangle called
occipital lymph nodes.
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(d) A group of supraclavicularlymph nodes.
? These nodes lie superficial to
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brachial plexus and subclavian
vessels.
Swelling in the posterior triangle
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? Most common cause of swelling in the posterior
triangle is due to enlargement of lymph nodes.
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? Supraclavicular lymph nodes are commonlyinvolved and enlarged in tuberculosis, Hodgkin's
disease, and malignant growth of breast, arm, and
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chest.
? Left supraclavicular lymph nodes (Virchow's lymph
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nodes) are commonly involved in metastasis fromcancer stomach, cancer testis, and cancer of other
abdominal organs.
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? The biopsy of these lymph nodes is helpful in early
diagnosis of distant malignancies.
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