Arm Flashcards
Anterior compartment of arm
Biceps Brachii
Brachialis
Coracobracialis
BBC
Biceps brachii O and I
O: long head - supraglenoid tubercle
short head - coracoid process scapula
I: Biceps tendon –> radial tuberosity and deep fascia of forearm (via bicipital aponeurosis)
Biceps brachii A and I
A: Strong supinator forearm
Flexes arm at elbow and shoulder
I: Musculocutaneous nerve
Bicep tendon reflex test
Tap inner elbow
Arm should flex at elbow
(C6 myotome responsible for elbow flexion and supination)
Rupture of biceps tendon
Long head rupture near scapula origin (50 yr+)
Hear ‘snap’ while lifting
Flexion produces large lump in lower arm ‘Popeye sign’
Weakness of flexion not noticed as brachialis and supinator is intact
(in weightlifters, ruptures near insertion)
Coracobrachilais O and I
Deep to short head of brachii
O: coracoid process
I: Medial humeral shaft
Coracobrachialis A and I
A: Flexes arm at shoulder, tight adductor (paper under arm)
I: Musculocutaneous nerve
brachialis O and i
Deep to biceps brachii
floor of cubital fossa
O: Anterior distal 2/3 humerus
I: Coronoid process of ulna/ulnar tuberosity
Brachialis A and I
A: Flexes forearm at elbow
I: Musculocutaneous nerve
Posterior arm artery supply
Profunda Brachii
Anterior arm artery and nerve supply
Brachial artery
ALL innervated by Musculocutaneous nerve
Posterior arm muscles
Triceps Brachii (Long head, lateral head and medial head)
Origins triceps brachii
Long: Infraglenoid tubercle of scapula
Lateral head: Shaft of humerus (superior to radial groove)
Medial head: Shaft of humerus (inferior to radial groove)
Insertion triceps brachii
Converge to tendon onto Olecranon of the ulna
Action and Innervation Triceps brachii
Action: Extends forearm at elbow, extends arm at shoulder
Innervation: Radial nerve
