Midterm- Arm Muscles

Question 1

Biceps brachii

Answer 1

Origin: Short head: coracoid process of scapula
Long head: supraglenoid tubercle of scapula
Insertion: bicipital (radial) tuberosity of radius via bicipital aponeurosis
Action: Flexion of forearm, supination of forearm from pronated position, assists with flexion, abduction, and stabilization of humerus
Innervation:Musculocutaneous C5, C6

Question 2

Corcacobrachialis

Answer 2

Origin: Tip of coracoid process of scapula
Insertion: Middle 1/3 of medial surface of humerus
Action: flexion of arm, adduction of arm, stabilization of glenohumeral joint
Innervation: Musculocutaneous C5, C6, C7

Question 3

Brachialis

Answer 3

Origin: Distal half of anterior surface of humerus
Insertion: coranoid process and ulnar tuberosity of ulna
Action: Flexion of forearm
Innervation: Musculocutaneous C5, C6

Question 4

Triceps brachii

Answer 4

Origin: Long head: infraglenoid tubercle
Medial head: posterior surface inferior to radial groove
Lateral head: posterior surface of humerus, superior to radial groove
Insertion: Olecranon process of ulna
Action: extension of forearm, long head also aids in extension of arm and resists dislocation of humerus during adduction of arm
Innervation: Radial C6, C7, C8

Question 5

Anconeus

Answer 5

Origin: Lateral epicondyle of humerus
Insertion: lateral surface of olecranon
Action: Assists triceps in extension of forearm, stabilization of elbow
Innervation: Radial C6, C7, C8