Muscles of Arm Flashcards
Where does the biceps brachii insert?
Radial tuberosity and fascia of forearm via bicipital aponeurosis
What is the origin of the biceps brachii?
Short head originates on the tip of the coracoid process of scapula
Long head originates on the supraglenoid tubercle of scapula
What is the innervation of the biceps brachii?
Musculocutaneous nerve (C5, C6)
What action does the biceps brachii perform?
Supinates forearm and, when it is supinated, flexes elbow joint and shoulder joint, short head resists dislocation of the shoulder
What is the origin of the brachialis?
Distal half of anterior surface of humerus
Where does the brachialis insert?
Coronoid process and ulnar tuberosity
What is the innervation of the brachialis?
Musculocutaneous nerve (C5, C6)
What action does the brachialis perform?
Flexes elbow joint in all positions
What is the origin of the coracobrachialis?
Tip of coracoid process of scapula
Where does the coracobrachialis insert?
Middle third of medial surface of humerus
What is the innervation of the coracobrachialis?
Musculocutaneous nerve (C5, C6, C7)
What action does the coracobrachialis perform?
Helps flex and adduct shoulder joint, resists dislocation of the shoulder
What is the origin of the triceps brachii?
Long head originates on the infraglenoid tubercle of humerus
Lateral head originates on the posterior surface of humerus, superior to radial groove
Medial head originates on posterior surface of humerus, inferior to radial groove
Where does the triceps brachii insert?
Proximal end of olecranon of ulna and fascia of forearm
What is the innervation of the triceps brachii?
Radial nerve (C6, C7, C8)
What action does the triceps brachii perform?
Chief extensor of elbow joint, long head extends shoulder jointand resists dislocation of humerus (important during abduction)
What is the origin of the anconeus?
Lateral epicondyle of humerus
Where does the anconeus insert?
Lateral surface of olecranon and superior part of posterior surface of ulna
What is the innervation of the anconeus?
Radial nerve (C7, C8, T1)
What action does the anconeus perform?
Assists triceps in extending elbow joint, stabilizes elbow joint, abducts ulna during pronation
