Arm

Question 1

Coracobrachialis

Answer 1

Attachments: coracoid process of scapula, 1/3 way down shaft of humerus

Actions: flexor of arm at glenohumeral joint; adducts arm, medial rotation

Innervation: Musculocutaneous N.

Blood supply: branches of brachial artery, anterior circumflex humeral artery

Question 2

Biceps Brachii

Answer 2

Attachments:
Long head (lateral)- supraglenoid tubercle of scapula
Short head (medial)- coracoid process of scapula
Both insert at radial tuberosity

Actions: flexor and supinator of forearm at elbow joint , accessory flexor of the arm

Innervation: Musculocutaneous N.

Blood supply: Muscular branches of brachial artery

Question 3

Brachialis

Answer 3

Attachments: Anterior shaft of humerus, ulnar tuberosity nd coronoid process of ulna

Actions: powerful flexor of forearm at elbow joint

Innervation: Musculocutaneous N., small contribution from radial nerve to lateral part

Blood supply: Muscular branches of brachial artery, recurrent radial artery

Question 4

Triceps Brachii

Answer 4

Attachments:
Long head- infraglenoid tubercle of scapula
Medial head- posterior surface of humerus, inferior to radial groove
Lateral head- posterior surface of humerus, superior to radial groove
Olecranon process of ulna

Actions: extension of forearm at elbow joint, long head can also extend and abduct the arm at the shoulder joint

Innervation: radial nerve (C5, C6, C7)

Blood supply: posterior circumflex humeral artery, Branches of deep brachial artery