Posterior triangle Flashcards
Boundaries
Anterior border of trapezius
Posterior border of sternocleidomastoid
Middle 1/3 of clavicle
Apex = superior nuchal line
Attachments of sternocleidomastoid
medial 1/3 clavicle and manubrium sterni
Mastoid process and superior nuchal line
Innervation of sternocleidomastoid
Spinal accessory nerve
What movement occurs when 1 sternocleidomastoid contracts?
Lateral movement - mastoid process to shoulder
What movement occurs when both sternocleidomastoid contract?
Bilateral flexion of the head and neck
Attachments of trapezius
Superior nuchal line and external occipital protuberance.
Vertebral column from C1 to T12
Lateral 1/3 of clavicle
Innervation of trapezius
Spinal accessory nerve
Function of trapezius
Rotate scapula and raise the arm
What muscles form the floor of the posterior triangle?
Splenius capitus, levator scapule, scalenus medius and posterior, scalenus anterior
What n. and a. are found deep in the posterior triangle?
Spinal accessory nerve runs through elevator scapule.
Phrenic nerve runs through scalenus anterior.
Brachial plexus and subclavian a. run in-between scalenus medius and anterior.
What cutaneous nerves can be seen on the superficial view of the posterior triangle?
Nerves of cervical plexus. Lesser occipital (C1-C2) Great auricular (C2-C3) Transverse cervical (C2-C3) Supraclavicular (C3-C4)
What muscle can be seen on the superficial view of the posterior triangle?
Omohyoid
What vein can be seen on the superficial view of the posterior triangle?
External jugular vein
What structures can be seen on the superficial view of the posterior triangle?
Cervical plexus - lesser occipital, great auricular, transverse cervical, supraclavicular
External jugular vein
Omohyoid
Where does the spinal accessory nerve enter the skull?
Fo. magnum
