muscles that cross the elbow joint

Question 1

Triceps Brachii

Answer 1

O: long head; infraglenoid tubercle of scapula. lateral head; posterior shaft of humerus. medial head; posterior humeral shaft distal to radial groove.
I: common tendon into olecranon process of ulna
N: radial nerve. roots c6 - c8
K: forearm extensor, may assist in adduction

Question 2

Anconeus

Answer 2

O: lateral epicondyle of humerus
I: lateral aspect of olecranon process of the ulna
N: radial nerve
K: controls ulnar abduction during forearm pronation, help with elbow extension

Question 3

Biceps Brachii

Answer 3

O: short head: coracoid process. long head: supraglenoid tubercle and lip of glenoid cavity, tendon of long head runs within capsule and into intertubercular sulcus of humerus
I: common tendon into radial tuberosity
N: musculocutaneous nerve. roots: c5, c6
K: flexes elbow joint and supinates forearm

Question 4

Brachialis

Answer 4

O: front of distal humerus, embraces insertion of deltoid muscle
I: coronoid process of ulna and capsule of elbow joint
N: musculocutaneous nerve
K: forearm flexion, lifts ulna as biceps lift radius

Question 5

Brachioradialis

Answer 5

O: lateral supracondylar ridge at distal end of humerus
I: base of styloid process of radius
N: radial nerve
K: forearm flexion, stabilizes elbow during rapid extension and flexion.