Posterior triangle of the neck
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Transcript of Posterior triangle of the neck
Posterior Triangle of the Neck
Learning objectives
• At the end of the lecture, the students will be able to:-
1. Describe posterior triangle of neck.2. List the contents of posterior triangle of neck.3. List common applied aspects.
The Neck• The region of the
body that lies between: The lower border
of mandible & The suprasternal
notch and the upper border of the clavicle
Triangles of the Neck
Posterior Triangle of the Neck
Subdivision of the Posterior Triangle
• Subdivided by the inferior belly of omohyoid muscle, into: Large occipital
triangle above Small
supraclavicular triangle below
Boundaries of occipital triangle
• Inferior belly of omohyoid
• Sternomastoid• trapezius
Boundaries of supraclavicular triangle
• Inferior belly of omohyoid
• Stenomastoid • Middle-third of clavicle
Boundaries• Anterior: Posterior border
of sternocleidomastoid• Posterior: Anterior border
of trapezius• Base: Middle third of
clavicle• Apex: superior nuchal line
of the occipital bone between the attachments of the trapezius and sternomastoid.
Platysma m.
Investing layer ofdeep cervical fascia
ROOF OF POSTERIOR TRIANGLE
CUTANEOUS BRANCHES OF THE CERVICAL PLEXUS
Lesser occipital n. (C2,3)
Great auricular n.(C2,3)
Transverse cervical n. (C2,3)
Supraclavicular nn. (C3,4)
CERVICAL PLEXUS
Muscular Floor of the Posterior Triangle
From above downward: Semispinalis capitis Splenius capitis Levator scapulae Scalenus medius Scalenus anterior may
or may not be present
Contents• Arteries:
Subclavian (3rd part) Superficial cervical &
suprascapular (branches of thyrocervical trunk, a branch of 1st part of subclavian artery
Occipital, a branch of external carotid artery
• Veins:• External jugular vein
Formation Termination
• Veins:• External jugular
vein Tributaries
• Nerves: Branches of
cervical plexus
Spinal part of accessory nerve
Brachial plexus
Sternocleidomastoid• Origin: Upper part of
manubrium & medial third of clavicle
• Insertion: Mastoid process & lateral part of superior nuchal line
• Nerve supply: Spinal part of accessory nerve (motor)
Sternocleidomastoid• Action:
• Both muscles acting together extend head at atlanto-occipital joint, and flex cervical part of vertebral column
• Contraction of one muscle moves the face to the opposite side
Trapezius
• Origin- medial third of superior nuchal line, external occipital protuberence, ligamentum nuchae, spine of seventh cervical vertebra and spines of all thoracic vertebrae.
Trapezius
• Insertion- upper fibers insert into the posterior aspects of lateral third of clavicle.
• Middle fibers insert into medial aspects of acromian and crest of the spine of scapula.
• Lower fibers insert into the crest of scapula.
Trapezius
• Action-Upper fibers elevate the scapula along with levator scapulae.
• Middle fibers cause retraction of scapula along with rhomboids.
• Lower fibers depresses and medially rotates the scapula.
Trapezius
• Nerve supply: Spinal part of accessory nerve (motor)
Omohyoid Muscle• Two bellies: Superior & Inferior
joined by intermediate tendon• Attachement: Superior belly to
inferior border of hyoid bone, Inferior belly to superior border of scapula & suprascapular ligament
• The Intermediate tendon lies deep to sternocleidomastoid
• Nerve supply: Ansa cervicalis (C1,2,3)
Superior belly
Intermediate tendon
Inferior belly
Action: Depresses the hyoid bone
Clinical Notes• Torticollis (wry neck):
Congenital: due to excessive stretching of sternocleidomastoid muscle during labor.
• Injury to spinal part of accessory nerve
• Injury to brachial plexus• Injury to nerve to platysma