Brachial Plexus Distribution

Question 1

What are all the distributions of A?

Answer 1

1. teres minor
2. deltoid
3. shoulder joints
4. skin over inferior half of deltoid (supplied by upper lateral cutaneous nerve of arm)

Question 2

What are all the distributions of B?

Answer 2

1. coracobrachialis
2. biceps brachii
3. brachialis
4. continues as lateral antebrachial cutaneous nerve (or lateral cutaneous nerve of forearm) and supplies the lateral border of the forearm

Question 3

What are all the distributions of C?

Answer 3

1. triceps brachii
2. anconeus
3. brachioradialis
4. extensor muscles of forearm (examples: extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum)
5. supplies skin on posterior aspect of arm and forearm (via posterior cutaneous nerves of arm and forearm)
6. articular branches to elbow, wrist and hand

Question 4

What are all the distributions of D?

Answer 4

1. flexor muscles in forearm (except carpi ulnaris, ulnar half of flexor digitorum profundus)
   examples: pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, flexor digitorum profundus)
2. the five hand muscles
   examples: palmer cutaneous branch to lateral half of palm and digital branches to palmar surface of lateral 3 1/2 fingers

Question 5

What are all the distributions of E?

Answer 5

1. flexor carpi ulnaris
2. flexor/abductor/adductor digiti minimi
3. medial half of flexor digitorum profundus
4. most small muscles in hand
5. skin of hand medial to a line bisecting 4th digit (the ring finger)

Question 6

1

Answer 6

rhomboids

occasionally the levator scapulae

Question 7

2

Answer 7

1. supraspinatus
2. infraspinatus
3. glenohumeral (shoulder) point

Question 8

3

Answer 8

1. subclavius

2. sternoclavicular joint

Question 9

4

Answer 9

serratus anterior

Question 10

5

Answer 10

primarily the pectoralis major

also sends a loop to medial pectoral nerve that innervates the pectoralis minor

Question 11

6

Answer 11

pectoralis minor

and part of the pectoralis major

Question 12

7

Answer 12

skin on medial side of arm

Question 13

8

Answer 13

skin over medial side of forearm

Question 14

9

Answer 14

superior portion of subscapularis

Question 15

10

Answer 15

latissimus dorsi

Question 16

11

Answer 16

1. inferior portion of subscapularis

2. teres major