Muscles of the Shoulder Girdle Continued

Question 1

Deltoid

Answer 1

Anterior, posterior, middle
Origin: Clavicle and Scapula
Insertion: Deltoid tuberosity of humerus
Action: Abduction at shoulder (Whole muscle)
Innervation:  Axillary nerve

Question 2

Pectoralis Major

Answer 2

Origin: Ribs 2-6, body of sternum
Insertion: Greater tubercle of humerus
Action: Flexion, adduction, and medial rotation at shoulder
Innervation: Pectoral nerves

Question 3

Supraspinatus

Answer 3

Origin: Supraspinatus fossa of scapula
Insertion: Greater tubercle of humerus
Action: Abduction at the shoulder
Innervation: suprascapular nerves

Question 4

Infraspinatus

Answer 4

Origin: Infraspinatus fossa of scapula
Insertion: Greater tubercle of humerus
Action: lateral rotation at shoulder
Innervation: Suprascapular nerve

Question 5

Teres Minor

Answer 5

Origin: Lateral border of scapula
Insertion: Greater tubercle of humerus
Action: Lateral rotation at shoulder
Innervation: Axillary nerve

Question 6

Teres Major

Answer 6

Not a part of the rotator cuff
Origin: Inferior angle of scapula
Insertion: Intertubercular groove of humerus
Action: extension, adduction, and medial rotation at shoulder
Innervation: lower subscapular nerve

Question 7

Subscapularis

Answer 7

Origin: Subscapular fossa of scapula
Insertion: Lesser Tubercle of humerus
Action: Medial rotation at the shoulder
Innervation: Subscapular nerves

Question 8

Latissimus Dorsi

Answer 8

Origin: Spinous process of inferior thoracic and lumbar vertebrae, ribs 8-12
Insertion: Intertubercular groove of humerus
Action: Extension, adduction, and medial rotation at shoulder
Innervation: Thoracodorsal nerve

Question 9

Coracobrachialis

Answer 9

Origin: Coracoid process of scapula
Insertion: Medial shaft of humerus
Action: adduction and flexion at shoulder
Innervation: Musculocutaneous nerve