Muscles that act on the arm (humerus) OIAs

Question 1

Pectoralis Major

Answer 1

Origin: clavicle, sternum and costal cartilages of upper ribs
Insertion: greater tubercle of humerus
Action: flexes, adducts, and medially rotates arm

Question 2

Latissimus Dorsi Action

Answer 2

Origin:
Insertion:
Action: Extends, adducts, and medially rotates arm

Question 3

Deltoid

Answer 3

Origin: Clavicle, acromion process and spine of scapula
Insertion: deltoid tuberosity of humerus
Action: abducts, flexes and extends, medially and laterally rotates arm

Question 4

Supraspinatus

Answer 4

Origin: Supraspinous fossa of scapula
Insertion: greater tubercle of humerus
Action: abducts arm and stabilizes glenohumeral joint

Question 5

Infraspinatus

Answer 5

Origin: infraspinous fossa of scapula
Insertion: greater tubercle of humerus
Action: laterally rotates arms and stabilizes glenohumeral joint

Question 6

Subscapularis

Answer 6

Origin: Subscapular fossa of scapula
Insertion: lesser tubercle of humerus
Action: medially rotates arm and stabilizes glenohumeral joint

Question 7

teres Minor

Answer 7

Origin: Axillary border of scapula
Insertion: intertubercular groove
Action: laterally rotates arm and adducts arm and stabilizes glenohumeral joint

Question 8

teres Major

Answer 8

Origin: Inferior angle of scapula
Insertion: lesser tubercle of humerus
Action: adducts, extends and medially rotates arm

Question 9

coracobrachialis

Answer 9

Origin: coracoid process of scapula
Insertion: medial surface of humerus
Action: flexes and adducts arm