Posterior Cervical Triangle

posterior triangle of neck is bound by

• SCM m.

• trapezius m.

• middle 1/3 of clavicle

what divides posterior triangle into two subsidiary triangles

inferior belly of the omohyoid m.

origin and insertion of omohyoid muscle

o: superior border of scapula

i: hyoid bone

what innervates omohyoid muscle

ansa cervicalis (C1- C3)

subclavian v. is anterior to

anterior scalene m.

subclavian a. and brachial plexus are posterior to

anterior scalene m.

subclavian a. is divided into three parts by

anterior scalene m.

1st part of subclavian a.

from origin of artery to medial border of anterior scalene m.

2nd part of subclavian a.

posterior to anterior scalene m.

3rd part of subclavian a.

from lateral border of anterior scalene m. to lateral border of 1st rib

transverse cervical artery travels anterior to

anterior scalene m.

transverse cervical artery splits into

superficial and deep branches

transverse cervical artery supplies

back musculature

suprascapular a. travels anterior to

anterior scalene m.

suprascapular a. travels inferiorly

near clavicle

suprascapular a. supplies

shoulder musculature

suprascapular a. is always below

transverse cervical a.

dorsal scapular a. is branch off

3rd part of subclavian a.

dorsal scapular a. travels

between components of brachial plexus

dorsal scapular a. supplies

back musculature

brachial plexus emerges

from between anterior and middle scalene m.

brachial plexus is network of

ventral primary rami of C5 - T1 that innervates upper extremities

C5 and C6 fuse into

superior trunk

C7 becomes

middle trunk

C8 and T1 fuse into

inferior trunk

dorsal scapular nerve comes off

C5 root

dorsal scapular n. pierces

middle scalene m.

dorsal scapular n. innervates

levator scapulae and rhomboid mm

nerve to subclavius comes off

superior trunk

nerve to subclavius innervates

subclavius m.

suprascapular n. comes off

superior trunk

suprascapular n. innervates

supraspinatus and infraspinatus

long thoracic n. comes off

C5, C6, C7 roots (straight down to thorax)

long thoracic n. pierces

middle scalene n.

long thoracic n. innervates

serratus anterior m.

CN XI (spinal accessory nerve) innervates

SCM m. and trapezius m.

CN XI (spinal accessory nerve) exits cranial cavity through

jugular foramen

CN XI (spinal accessory nerve) enters cranial cavity through

foramen magnum

subsidiary triangles within the posterior cervical triangle

supraclavicular and occipital

facial layer that covers floor of the posterior cervical triangle

prevertebral fascia

vessels found in the posterior triangle of the neck

• Dorsal scapular artery

• Suprascapular artery

• Subclavian vein

• Transverse cervical artery

• 3rd part of subclavian artery

intermediate tendon of the omohyoid muscle attaches to

clavicle