Axilla, Brachial Plexus and Upper Limb (FA and AA)

Question 1

What are the 4 rotator cuff muscles?

Answer 1

1) Supraspinatus (Abd)
2) Infraspinatus (ER)
3) Teres Minor (ER)
4) Subscapularis (IR)

Question 2

What do the rotator cuff muscles do?

Answer 2

Stabilise the shoulder joints

Question 3

What is deltoids innervation and function?

Answer 3

1) Axillary nerve

2) Abduction of the arm

Question 4

What is the axilla?

Answer 4

Area underneath shoulder joint at junction between UL and Thorax (armpit)

Question 5

What structures form borders of axilla?

Answer 5

A: 1st Rib, Clavicle and Scapula
MW: SAnterior, Ribs and Intercostal
LW: Upper Humerus, biceps brachii and coracobrachialis
AW: Pec Major and Minor
PW: Latissimus dorsi, teres major and subscapularis
B: Skin and deep fascia

Question 6

What are 5 components found in the axilla?

Answer 6

1) Fat
2) Lymph Nodes
3) Axillary Artery
4) Brachial Plexus
5) Axillary Vein

Question 7

What spinal nerve roots form the brachial plexus?

Answer 7

C5-T1

Question 8

What are the divisions of BP?

Answer 8

Roots –> Trunk –> Divisions –> Cords –> Branches

Question 9

What are the 5 main branches of the BP?

Answer 9

1) Ulnar 2) Median 3) Musculotaneous (UMM)

Radial and Axillary

Question 10

What are the nerve roots for each branch?

Answer 10

Musc: C5,6,7
Axill: C5,6
Median: C6,7,8, T1
Radial: C5,6,7,8 T1
Ulnar: C8, T1

Question 11

What are the three trunks of BP?

Answer 11

1) Superior Trunk (C5,6)
2) Middle Trunk (C7)
3) Inferior Trunk (C8,T1)

Question 12

What are the 3 cords of the BP?

Answer 12

1) Lateral Cord
2) Posterior Cord
3) Medial Cord

Question 13

What divisions form each cord

Answer 13

L: Anterior divisions of S and M trunks
P: Post divisions of S,M and I Trunks
M: Anterior division of I trunk

Question 14

What does the Musculotaneous nerve innervate?

Answer 14

M: Anterior flexors: Brachialis, BB, CB (BBC)
S: Lateral Forearm

Question 15

What does the axillary nerve innervate?

Answer 15

M: Abductors of arm at shoulder: Teres Minor, Long head of triceps and deltoid
S: Skin over the lower deltoid

Question 16

What does the median nerve innervate?

Answer 16

M: Flexors in anterior forearm, thenar muscles and lateral two lumbricals (LLOAF)
S: Lateral palm of hand and lateral 3.5 fingers

Question 17

What does the radial nerve innervate?

Answer 17

S: Skin on posterior side of forearm and hand
M: Triceps brachii, elbow extension, innervation of extensor muscles in forearm posterior compartment

Question 18

What does the ulnar nerve innervate?

Answer 18

M: Muscles of hand, flexor carpi ulnaris, medial half of flexor digitorum profunuds
S: Medial 1.5 fingers and medial palm

Question 19

What is found in the cubital fossa? (L–>M)

Answer 19

Biceps Tendon
Brachial Artery
Median Nerve (TAN)

Question 20

What does brachialis do?

Answer 20

Flexion of the elbow joint

Question 21

What is the action of biceps brachii?

Answer 21

Flexion of elbow joint and forearm supination

Question 22

What cord transection of BP paralyses BBC?

Answer 22

Lateral Cord

Question 23

What are 4 1 2 1 muscles of anterior forearm? (S–> Deep)

Answer 23

1) Pronator Teres, Flexor carpi radialis, flexor carpi ulnaris and Palmaris Longus (All from medial epicondyle)
2) Flexor digitorum superficialis
3) Flexor pollicis longus, flexor digitorum profundus
4) Pronator quadrat

Question 24

What is the action of flexor digitorum profundus?

Answer 24

Flexes interphalangeal and metacarpophalangeal joints