Neck & Back: Brachial Plexus Flashcards
components of brachial plexus
spinal cord → dorsal and ventral nerve root
nerve roots exit via horns of spinal cord
dorsal & ventral roots combine = spinal nerves
brachial plexus is comprised of ventral rami of spinal nerves C5-T1
main nerve supply to upper limb, chest, back
split into sections: roots → trunks → divisions → cords → terminal branches
location
emerges from lower neck
goes under clavicle 7 chest muscles (protection)
emerges from axilla
lies anteromedially in upper arm
roots
C5
C6
C7
C8
T1
trunks
superior
middle
inferior
divisions
3 anterior
3 posterior
cords
lateral
posterior
medial
terminal branches
axillary nerve
radial nerve
musculocutaneous nerve
median nerve
ulna nerve
relation to axillary artery
cords - names according to their position relative to the axillary artery
axillary artery goes over C8/T1 & runs superior (and parallel) to it
goes over posterior cord
under “M”
relation to pectoralis minor
cords & axillary artery run deep to pectoralis minor
pectoralis minor divides axillary artery into 3 parts
terminal branches of brachial plexus form at the lateral border of pectoralis minor
musculocutaneous innervation
cutaneous: forearm
muscles: anterior arm
median innervation
cutaneous: hand
muscles: most of the anterior forearm
ulnar innervation
cutaneous: some hand
muscles: most of the intrinsic muscles of the hand
axillary innervation
cutaneous: shoulder & some posterior arm
muscles: some shoulder girdle muscles
radial innervation
cutaneous: some skin of the forearm
muscles: all posterior arm & some posterior forearm muscles
sensory cutaneous innervation
dermatome innervation: area of skin supplied by 1 spinal nerve
cutaneous innervation: skin supplied by peripheral nerves
