Muscles Crossing The Shoulder Joint

Question 0

Insertion of pectoralis major

Answer 0

Fibers converge to insert by a short tendon into greater tubercle of humerus

Question 1

Origin of pectoralis major

Answer 1

Sternal end of clavicle, sternum, cartilage of ribs 1-6, and aponeurosis of external oblique

Question 2

Action of pectoralis major

Answer 2

Prime mover of arm Flexion; rotates arm medially; Adducts arm

Question 3

Innervation of pectoralis major

Answer 3

Lateral and medial pectoral nerves

Question 4

Origin of deltoid

Answer 4

Embraces insertion of the trapezius; Lateral third of clavicle; acromion and spine of scapula

Question 5

Insertion of deltoid

Answer 5

Deltoid tuberosity of humerus

Question 6

Action of deltoid

Answer 6

Prime mover of arm abduction when all its fibers contract simultaneously

Question 7

Innervation of deltoid

Answer 7

Axillary nerve

Question 8

Origin of latissimus dorsi

Answer 8

Indirect attachment via thoracolumbar fascia into spines of lower six thoracic vertebrae, lumbar vertebrae, lower 3-4 ribs, and iliac crest

Question 9

Insertion of latissimus doris

Answer 9

Spirals around teres major to insert in floor of inter tubercular sulcus of humerus

Question 10

Action of latissimus dorsi

Answer 10

Prime mover of arm extension; adduction and medial rotation at shoulder

Question 11

Innervation of latissimus dorsi

Answer 11

Thoracodorsal nerve

Question 12

Origin of teres major

Answer 12

Posterior surface of scapula at inferior angle

Question 13

Insertion of teres major

Answer 13

Crest of lesser tubercle on anterior humerus; insertion tendon fused with that of latissimus dorsi

Question 14

Action of teres major

Answer 14

Extends, medially rotates, and Adducts humerus

Question 15

Innervation of teres major

Answer 15

Lower Subscalpular nerve

Question 16

Origin of subscalpularis

Answer 16

Subscalpular fossa of scapula

Question 17

Insertion of subscalpularis

Answer 17

Lesser tubercle of humerus

Question 18

Action of subscalpularis

Answer 18

Chief medial rotator of humerus

Question 19

Innervation of subscalpularis

Answer 19

Subscalpular nerves

Question 20

Origin of supraspinatus

Answer 20

Supraspinous fossa of scapula

Question 21

Insertion of supraspinatus

Answer 21

Superior part of greater tubercle of humerus

Question 22

Action of supraspinatus

Answer 22

Initiates abduction

Question 23

Innervation of supraspinatus

Answer 23

Suprascapular nerve

Question 24

Origin of infraspinatus

Answer 24

Infraspinous fossa of scapula

Question 25

Insertion of infraspinatus

Answer 25

Greater tubercle of humerus posterior to insertion of supraspinatus

Question 26

Action of infraspinatus

Answer 26

Rotates humerus laterally

Question 27

Innervation of infraspinatus

Answer 27

Suprascapular nerve

Question 28

Origin of teres minor

Answer 28

Lateral border of dorsal scapular surface

Question 29

Insertion of teres minor

Answer 29

Greater tubercle of humerus inferior to infraspinatus insertion

Question 30

Action of teres minor

Answer 30

Rotates humerus laterally

Question 31

Innervation of teres minor

Answer 31

Axillary nerve

Question 32

Origin of coracobrachialis

Answer 32

Coracoid process of scapula

Question 33

Insertion of coracobrachialis

Answer 33

Medial surface of humerus shaft

Question 34

Action of coracobrachialis

Answer 34

Flexion and adduction of humerus

Question 35

Innervation of coracobrachialis

Answer 35

Musculocutaneous nerve