Muscles Of The Arm Flashcards
Insertion of biceps brachii
Tuberosity of radius and fascia of forearm via bicipital aponeurosis
Origin of biceps brachii
Short head: tip of coracoid process of scapula
Long head: supraglenoid tubercle of scapula
Innervation of biceps brachii
Musculocutaneous nerve (c5 and c6)
Actions of biceps brachii
Supinates forearm and, when it is supinated, flexes elbow joint; flexes shoulder joint, short head resists dislocation of the shoulder
Origin of brachialis
Distal half of anterior surface of humerus
Insertion of brachialis
Coronoid process and tuberosity of ulna
Innervation of brachialis
Musculocutaneous nerve (c5 and c6)
Action of brachialis
Flexes elbow joint in all positions
Also steadies elbow extension by slowly relaxing
Origin of coracobrachialis
Tip of coracoid process of scapula
Insertion of coracobrachialis
Middle third of medial surface of humerus
Innervation of coracobrachialis
Musculocutaneous nerve (c5, c6, c7)
Action of coracobrachialis
Helps flex and adduct shoulder joint
Resists dislocation of shoulder
Origin of triceps brachii
Long head: infraglenoid tubercle of scapula
Lateral head: posterior surface of humerus, superior to radial groove
Medial head: posterior surface of humerus, inferior ro radial groove
Insertion of triceps brachii
Proximal end of olecranon of ulna and fascia of forearm
Innervation of triceps brachii
Radial nerve (c6, c7, c8)
Actions of triceps brachii
Chief extensor of elbow joint; long head extends shoulder joint and resists dislocation of humerus (especially important during abduction)
Origin of anconeus
Lateral epicondyle of humerus
Insertion of anconeus
Lateral surface of olecranon and superior part of posterior surface of ulna
Innervation of anconeus
Radial nerve (c7, c8, t1)
Actions of anconeus
Assists triceps in extending elbow joint, stabilizes elbow joint, abducts ulna during pronation
What are the two types of movement that occur at the elbow joint?
Flexion-extension and pronation-supination
The muscles of the arm are divided into two groups, what are they called and where are they located?
There are three flexors in the anterior compartment and one extensor in the posterior compartment with another muscle that assists in extension and pronation
Which muscles of the arm are considered flexors?
Biceps brachii, brachialis, and coracobrachialis
What arm muscles are considered extensors?
Triceps brachii and the anconeus (which helps out the triceps in extension)