muscles of the arm and posterior forearm Flashcards
biceps brachii origin
short head: coracoid process of the scapula
long head: supraglenoid tubercle of the scapula
biceps brachii insertion
both the short and long head: tuberosity of the radius
biceps brachii innervation
musculocutaneous nerve (C5,C6)
biceps brachii action
supinates the forearm, flexes the elbow, flexes the shoulder joint
the short head helps to resist dislocation of shoulder
brachialis origin
distal hald of the anterior surface of the humerus
brachialis insertion
coronoid process and tuberosity of the ulna
brachialis innervaton
Musculocutaneous nerve
brachialis action
flexes elbow joint in all positions
coracobrachialis origin
coracoid process of the scapula
coracobrachialis insertion
middle third of medial surface of humerus
coracobrachialis innervation
musculocutaneous nerve
coracobrachialis action
helps flex and adduct should joint, resisits disloction of the shoulder
triceps origin of the long head
infreglenoid tubercule of the scapula
triceps origin of the lateral head
posterior surface of the humerus, superior to radial groove
triceps origin of the medial head
posterior surface of humerus inferior to the radial groove
triceps insertion (all three)
olecranon of the ulna and fasica of the forearm
triceps innervation (all three)
radial nerve
triceps action (all three)
- main extensor of the elbow joint
- long head extends shoulder joint and resists dislocation
anconeus origin
lateral epicondyle of humerus
anconeus insertion
lateral surface of the olcranon and superior part of posterior surface of the ulna
anconeus innervation
radial nerve
anconeus action
assiss triceps in extending the elbow
stablizes the elbow joint
adducts ulna during pronation
Branchioradialis origin
lateral supracondylar ridge of the humerus
Brachioradialis insertion
lateral suraface of distal end of radius proximal to the styloid process
brachioradialis innervation
radial nerve
brachioradials action
weak flexion of the elbow, maximal when forearm is in midpronated position