upper limb nerves

Question 1

where do nerves of brachial plexus come from

Answer 1

From roots C5-T1 (in cervical, nerve roots name is vertebrae below, in thoracic its names from vertebrae above. There is a C8 root between C7 and T1)
The nerve roots come out between 2 of the scalene muscles (anterior and medial)- called the inter-scalene space

Question 2

draw the brachial plexus tree

Answer 2

look in FA notebook

Question 3

relevance of axillary artery

Answer 3

passes through axilla then anterior to the divisions
Cords relative position to artery gives their name as it passes through middle of them

Question 4

posterior cord peripheral nerves (2)

location, innervation, sensory distribution

Answer 4

Axillary nerve-
location= Wraps under axilla/ armpit, then round head of
humerus
Innervation= teres minor, deltoid
Sensory distribution= superior lateral cutaneous nerve of
arm branches off supplying skin over the deltoid

Radial nerve-
location= Into posterior compartment of arm through a
triangle created by humerus, teres major and long head
of triceps brachii. Wraps posteriorly around the humerus
alongside the spiral grove of the humerus, before it
comes back anteriorly superior to elbow joint which it
then crosses and travels along radius (lateral), then wrist
and innervates thumb and first 3 fingers on back of hand.
Innervation= triceps x3, brachioradialis, extensor carpi
radialis longus and brevis, supinator, extensor carpi
ulnaris, extensor digitorum, extensor digiti minimi,
abductor pollicis longus, extensor pollicis longus and
brevis, extensor indicis.
Sensory distribution= inferior lateral cutaneous nerve of
arm, posterior cutaneous nerve of arm, and posterior
cutaneous nerve of forearm sensing skin on posterior
aspect of arm (triceps, posterior forearm, lateral half of
backhand, first 3 and a half fingers)

Question 5

lateral and medial cord peripheral nerves (3)

location, innervation, sensory distribution

Answer 5

Musculocutaneous nerve-
Location= down anterior compartment of arm supplying
elbow flexors. Superficial to brachialis, deep to biceps,
then down forearm
Innervation= coracobrachialis, biceps, brachialis
Sensory distribution= lateral cutaneous nerve of forearm
for skin of lateral side of forearm

Median nerve-
Location= Down medial aspect of arm, the goes more
central as it reaches wrist, passes through carpal tunnel,
branching into all fingers
Innervation= pronator teres, flexor carpi radialis, palmaris
longus, flexor digitorum superficialis, adductor pollicis
brevis, flexor pollicis brevis, opponens pollicis, first and
second lumbrical. In form arm branches into anterior
interosseus nerve innervating flexor digitorum profundus,
flexor pollicis longus and pronator quadratus
Sensory distribution= palmar aspect of first 3 and half
fingers and entire finger tips

Ulnar nerve-
Location= Most medial of nerves, crosses shoulder
posterior to medial epicondyle of elbow (funny bone)
running down medial forearm entering hand at pinky side
of hand.
Innervation= flexor carpi ulnaris, flexor digitorum
profundus, adductor pollicis, flexor pollicis brevis, first
dorsal and first palmar interossei, fourth and third
lumbrical.
Sensory distribution= other half of hand that isn’t
innervated by median and radial nerve