Muscles Of The Arm (MA) Flashcards
Anterior Compartment: (All Innervated by Musculocutaneous Nerve, and all flexors)
*Coracobrachialis
Origin: Coracoid process of the scapula
Insertion: middle 1/3 of the medial surface of humerus
Innervation: musculocutaneous nerve (C5,C6,C7)
Main action: flexion and adduction of the shoulder joint.
Anterior Compartment: (All Innervated by Musculocutaneous Nerve, and all flexors)
*Biceps brachii
Origin: long head: supraglenoid tubercle of the scapula; short head; coracoid process of the scapula
Insertion: radial tuberosity and fascia of the forearm via the bicipital aponeurosis
Innervation: musculocutaneous nerve (C5,C6)
Main action: flexes the elbow joint when forearm is supinated; supinates forearm forearm; flexed the shoulder joint
Anterior Compartment: (All Innervated by Musculocutaneous Nerve, and all flexors)
- Brachialis
Origin: distal 1/2 of anterior surface of the humerus
Insertion: Coronoid process and tuberosity of the ulna
Innervation: musculocutaneous nerve (C5-C7)
Main actions: flexes the elbow joint (regardless of the forearm position)
Posterior Compartment: (all innervated by the Radial Nerve, and are all extensor muscles)
- Triceps brachii
Origin: Long head: infraglenoid tubercle of scapula, lateral head: posterior - superior surface (laterally) of the humerus; Medial head: posterior - superior surface (medially) of the humerus
Insertion: posterior surface of the olecranon and fascia of the forearm
Innervation: radial nerve (C6,C7,C8)
Main actions: extends the elbow joint; long head also extends the shoulder joint.
Posterior Compartment: (all innervated by the Radial Nerve, and are all extensor muscles)
*Anconeus
Origin: posterior surface of lateral epicondyle of humerus
Insertion: lateral aspect of the olecranon process and superior part of the posterior ulna
Innervation: radial nerve (C7,C8,T1)
Main actions: assists triceps in producing elbow extension; plays a small role in forearm pronation.
