Intrinsic Muscles

Question 1

Deltoideus: Insertion

Answer 1

Insertion: deltoid tuberosity of the humerus

Question 2

Deltoideus: Action

Answer 2

Action: flex shoulder

Question 3

Name the two parts of the deltoideus.

Answer 3

1) scapular

2) spinal

Question 4

Infraspinatus: Origin

Answer 4

Origin: infraspinous fossa of the scapula

Question 5

Infraspinatus: Insertion

Answer 5

Insertion: lateral side of the greater tubercle of the humerus (small, circumscribed area)

Question 6

Infraspinatus: Action

Answer 6

Action:

1) laterally stabilizes the shoulder
2) abduct and laterally rotate shoulder
3) assists other muscles in the extension or flexion of shoulder

Question 7

There’s minor: Origin

Answer 7

Origin:

1) infraglenoid tubercle of the scapula
2) distal caudal border of scapula

Question 8

Teres minor: Insertion

Answer 8

Insertion: Teres minor tuberosity of humerus

Question 9

Teres minor: Action

Answer 9

Action:

1) laterally stabilizes for shoulder
2) laterally rotate shoulder
3) flex shoulder

Question 10

Supraspinatus: Origin

Answer 10

Origin: supraspinous fossa of the scapula

Question 11

Supraspinatus: Insertion

Answer 11

Insertion: greater tubercle of the humerus

Question 12

Supraspinatus: Action

Answer 12

Action:

1) laterally stabilizes the shoulder
2) extend shoulder

Question 13

Subscapularis: Origin

Answer 13

Origin: subscapular fossa of the scapula

Question 14

Subscapularis: Insertion

Answer 14

Insertion: lesser tubercle of the humerus

Question 15

Subscapularis: Action

Answer 15

Action:

1) Medially stabilizes the shoulder
2) adduct shoulder
3) extend shoulder

Question 16

Teres major: Origin

Answer 16

Origin:

1) caudal angle and caudal border of the scapula
2) subscapularis muscle

Question 17

Teres major: Insertion

Answer 17

Insertion: Teres major tuberosity of the humerus

Question 18

Teres major: Action

Answer 18

Action: flex shoulder, rotate arm medially

Question 19

Coracobrachialis: Origin

Answer 19

Origin: coracoid process of the scapula

Question 20

Coracobrachialis: Insertion

Answer 20

Insertion: crest of the lesser tubercle of the humerus, near Teres major tuberosity

Question 21

Coracobrachialis: Action

Answer 21

Action: mainly stabilizes the shoulder, but can assist other muscles in adduction and/or extension of shoulder

Question 22

Tensor fasciae antebrachii: Origin

Answer 22

Origin: fascia covering the lateral surface of the latissimus dorsi muscle

Question 23

Tensor fasciae antebrachii: Insertion

Answer 23

Insertion: olecranon of the ulna

Question 24

Tensor fasciae antebrachii: Action

Answer 24

Action: extend elbow

Question 25

Name the 4 heads of the triceps brachii.

Answer 25

1) long head
2) lateral head
3) medial head
4) accessory head

Question 26

Triceps brachii: Origin

Answer 26

Origin:

1) caudal border of the scapula (LONG HEAD)
2) tricipital line

Question 27

Triceps brachii: Insertion

Answer 27

Insertion: olecranon of ulna

Question 28

Triceps brachii: Action

Answer 28

Action:

1) flex shoulder (LONG HEAD)
2) extend elbow

Question 29

Anconeus: Origin

Answer 29

Origin:

1) lateral supracondylar crest of humerus
2) lateral and medial epicondyles of humerus

Question 30

Anconeus: Insertion

Answer 30

Insertion: proximal and lateral aspect of the ulna

Question 31

Anconeus: Action

Answer 31

Action: extend elbow

Question 32

Biceps brachii: Origin

Answer 32

Origin: supraglenoid tubercle of the scapula

Question 33

Biceps brachii: Insertion

Answer 33

Insertion: radial and ulnar tuberosities

Question 34

Biceps brachii: Action

Answer 34

Action: extend shoulder and flex elbow

Question 35

Brachialis: Origin

Answer 35

Origin: proximal and lateral aspect of the humerus

Question 36

Brachialis: Insertion

Answer 36

Insertion: radial and ulnar tuberosities

Question 37

Brachialis: Action

Answer 37

Action: flex elbow

Question 38

Deltoideus: Origin

Answer 38

Origin: spine and acromial process of scapula