Exam 2 - Upper Limb Muscles Flashcards
Biceps brachii - origin/ proximal
short head: tip of coracoid process of scap
long head: supraglenoid tubercle of scap
Biceps brachii - insertion/ distal
tuberosity of radius and fascia of forearm via bicipital aponeurosis
Biceps brachii - innervation
musculocutaneous n. (C5-C7)
Biceps brachii - action
- supinates forearm and, when supinated, flexes forearm
- short head resists dislocation of shoulder
Coracobrachialis - origin/ proximal
tip of coracoid process of scap
Coracobrachialis - insertion/ distal
middle third of medial surface of humerus
Coracobrachialis - innervation
musculocutaneous n. (C5-C7)
Coracobrachialis - action
- helps flex and adduct arm
- resists dislocation of shoulder
Brachialis - origin/ proximal
distal half of anterior surface of humerus
Brachialis - insertion/ distal
coronoid process and tuberosity ulna
Brachialis - innervation
musculocutaneous n. (C5, C6) and radialis n. (C5, C7)
Brachialis - action
flexes forearm in all positions
Triceps brachii - origin/ proximal
long head: infraglenoid tubercle of scap
lateral head: posterior surface of humerus, superior to radial groove
medial head: posterios surface of humerus, inferior to radial groove
Triceps brachii - insertion/ distal
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 resists dislocation of humerus
- especially important during adduction
Anconeus - origin/ proximal
lateral epicondyle of humerus
Anconeus - insertion/ distal
lateral surface of olecranon and superior part of posterior surface of ulna
Anconeus - innervation
radial n. (C7, C8, T1)
Anconeus - action
- assists triceps in extending forearm
- stabilizes elbow joint
- may abduct ulna during pronation
