Posterior Triangles of the Neck Flashcards
Borders of the posterior triangle
Sternocleidomastoid muscle, trapezius muscle, clavicle
Subtriangles of the posterior triangle
OCCIPITAL TRIANGLE (above omohyoid), SUPRACLAVICULAR[omoclavicular] below omohyoid
What innervates the Sternocleidomastoid?
CN XI. It also innervates the trapezius muscle
What is the occipital triangle part? What are the occipital triangle’s contents?
Occipital triangle= section of posterior triangle above the omohyoid
Contains Erb’s point (cutaneous branches of cervical plexus +accessory nerve XI).
Its floor is the posterior scalene, middle scalene, levator scapulae and some of the splenius capaitis
Erb’s point
Area halfway along posterior border of the sternocleidomastoid which is point to find the following nerves:
Cutaneous branch of cervical plexus (lesser occipital nerve, great auricular nerve, supraclavicular nerve, transverse cervical nerves)
Cranial nerve XI
Cutaneous branches of the cervical plexus
- Transverse cervical nerve
- Great auricular nerve
- Lesser occipital nerve
- Supraclavicular nerve
What is the supraclavicular triangle? What are the supraclavicular triangle’s contents?
Supraclavicular (aka omoclavicular) triangle= section of posterior triangle below omohyoid
Contents: Lower portion of brachial plexus, subclavian artery and vein, branches of subclavian (VIT C and D), termination of external jugular vein
Floor- anterior scalene, 1st rib, upper portion of serratus anterior
Motor portion of the cervical plexus
Lies deep to sensory portion. Much can be found in carotid triangle.
(a) phrenic nerve- sits on anterior scalene
(b) ansa cervicalis [ C1 ventral rami= superior root] C2 and C3 ventral rami= inferior root
(c) ventral rami
VIT C & sometimes D
Subclavian artery brnch designations:
Segent #1: V=vertebral artery, I= Internal thoracic artery, T=thyrocervical trunk
Segment #2: (behind anterior scalene) C= costocervical trunk
Segment #3: D= dorsal scapular
Where does the subclavian vein run?
Behind the clavicle and in front of the anterior scalene
Where do the subclavian artery and brachial plexus run?
Between the anterior scalene and the middle scalene.
Function of omohyoid muscle.
Depresses the hyoid and draws the larynx and hyoid bone down for phonation and swallowing.
Superior and Inferior bellies of the omohyoid are innervated by:
Ansa
Function of the splenius capitis and splenius cervicis
Bilaterally: to extend the cervical spine and head
Unilaterally: to flex and rotate the head to the same side.
“Sleeve” binding all structures in the neck? Where does it attach?
Investing layer of dense connective tissue. Attached to ligamentum nuchae and C7 vertebrate.
