Muscles Of Arm Flashcards
Biceps brachii Insertion
Tuberosity of radius and fascia of forearm via bicipital aponeurosis
Biceps brachii origin
Short head: tip of coracoid process of scapula
Long head: supraglenoid tubercle of scapula
Biceps brachii Innervation
Musculocutaneous Nerve (C5, C6)
Biceps brachii Action
Supinates forearm and, when it is supinated, flexes forearm
Flexes arm
Short head resists dislocation of shoulder
Brachialis Origin
Distal half of anterior surface of humerus
Brachialis Insertion
Coronoid process and tuberosity of ulna
Brachialis Innervation
Musculocutaneous nerve (C5, C6)
Brachialis Action
Flexes forearm in all positions
Coracobrachialis Origin
Tip of coracoid process of scapula
Coracobrachialis Insertion
Middle third of medial surface humerus
Coracobrachialis Innervation
Musculocutaneous Nerve (C5, C6, C7)
Coracobrachialis Action
Helps flex and adduct arm
Resists dislocation of shoulder
Triceps brachii Origin
Long head: infraglenoid tubercle of scapula
Lateral head: posterior surface of humerus, superior to radial groove
Medial head: posterior surface of humerus, inferior to radial groove
Triceps brachii Insertion
Proximal end of olecranon of ulna and fascia of forearm
Triceps brachii Innervation
Radial Nerve (C6, C7, C8)
Triceps brachii Action
Chief extensor of forearm
Long head extends arm and resists dislocation of humerus (especially important during abduction)
Anconeus Origin
Lateral epicondyle of humerus
Anconeus Insertion
Lateral surface of olecranon and superior part of posterior surface of ulna
Anconeus Innervation
Radial nerve (C7, C8, T1)
Anconeus Action
Assists triceps in extending forearm
Stabilizes elbow joint
Abducts ulna during pronation
Cubital Fossa Boundaries
Superiorly: imaginary line connecting medial and lateral epicondyles
Medially: pronator teres
Laterally: brachioradialis
Floor: brachialis and supinator muscles
Roof: continuity of brachial and antebrachial (deep) fascia, reinforced by the bicipital aponeurosis, subcutaneous tissue, and skin
Cubital Fossa Contents
1) Terminal part of brachial artery and the commencement of its terminal branches, the radial and ulnar arteries; brachial artery lies between biceps tendon and median nerve
2) (deep) accompanying veins of the arteries
3) biceps brachii tendon
4) median nerve
5) radial nerve, dividing into superficial and deep branches
