Part 5: Anterior Compartment of Arm

Question 1

Name the muscles located in anterior arm?

Answer 1

Corocabrachialis, Biceps Brachii, Brachialis

Question 2

Coracobrachialis origin, insertion, action and innervation

Answer 2

O: Coracoid process of scapula
I: Middle 3rd medial border of humerus
A: Weak flexor and adductor
N: Musculocutaneous (C5,6,7 from lat cord)(pierces muscles)

Question 3

Biceps Brachii origin, insertion, action and innervation

Answer 3

O: Long head - supraglenoid tubercle, short head - coracoid process
I: Post border bicipital tuberosity of radius nd bicipital aponeurosis to ulna via deep fascia
A: Supinator, flexor of elbow and weak flexor of shoulder
N: Mscn (C5,6) lat cord

Question 4

Brachialis origin, insertion, action and innervation

Answer 4

O: Anterior lower 2/3 humerus and medial IM septum. Upper fibres clasp deltoid insertion.
I: Coronoid process and tuberosity of ulna
A: Major flexor of elbow. Also some involvement preventing capsular nipping
N: Mscn (C5,6) lat cord and small supply from radial nerve

Question 5

Branches of brachial artery

Answer 5

Profunda brachii - leaves through triangular space to triceps
Superior and Inferior ulna collaterals
Nutrient artery to humerus
Ends by dividing into radial and ulna in cubital fossa

Question 6

Brachial art course

Answer 6

Continuation of axillary (starts lower border teres maj)
Median nerve initially lateral then crosses in front to lie medial
Ulnar nerve is posterior then leaves via medial IM septum.
Runs superficial - immediately deep to deep fascia

Question 7

Veins of arm

Answer 7

Venae comitantes accompany brachial a
Basilic vein courses upwards and perforates deep fascia of middle arm
Cephalic is lateral to biceps - enters at axillary vein

Question 8

Median Nerve in arm

Answer 8

Crosses brachial art from lateral to medial

No branches in arm - gives sympathetic filaments and twig to elbow joint

Question 9

Musculocutaneous nerve

Answer 9

Supplies flexor compartment of arm
Pierces coracobrachialis and lies between biceps and brachialis supplying both. Remaining fibres form the lateral cutaneous nerve of forearm

Question 10

Ulnar nerve

Answer 10

Lies post to vessels then pierces medial IM septum to run more posterior. No branches in arm

Question 11

Medial cutaneous nerve of arm supply

Answer 11

Skin on front and medial side of upper arm

Question 12

Intercostalbrachial nerve

Answer 12

lat cutaneous branch of 2nd IC - supplies axilla and skin on medial side of upper arm

Question 13

Lymph nodes of arm

Answer 13

2 groups not part of axilla:

• infraclaviclar group (cephalic vein, deltopectoral grove)
• supratrochlear group (subcut tissue medial epicondyle)