Arm Muscles

Question 1

Pectoralis major (attachment)

Answer 1

Clavicular head: clavicle AND bicipital groove of humerus

Sternocostal head: sternum and costal cartilages AND bicipital groove of humerus

Question 2

Pectoralis major (innervation)

Answer 2

Lateral pectoral nerve (C5-C7):
-clavicular head (C5-C6)
-sternocostal head (C7)
Medial pectoral nerve (C8-T1):
-sternocostal head (C8-T1)

Question 3

Pectoralis major (action)

Answer 3

Clavicular head: flexes arm
Sternocostal head: extends arm from a flexed position
Both: aDducts and medially rotates arm

Question 4

Pectoralis minor (attachment)

Answer 4

Upper ribs AND coracoid process of scapula

Question 5

Pectoralis minor (innervation)

Answer 5

Medial pectoral nerve (C8-T1)

Question 6

Pectoralis minor (action)

Answer 6

Stabilizes scapula against thoracic wall, elevates upper ribs

Question 7

Subclavius (attachment)

Answer 7

1st rib AND clavicle

Question 8

Subclavius (innervation)

Answer 8

Nerve to subclavius (C5-C6)

Question 9

Subclavius (action)

Answer 9

Depresses clavicle

Question 10

Deltoid-Anterior (attachment)

Answer 10

Clavicle AND deltoid tuberosity of humerus

Question 11

Deltoid-Anterior (innervation)

Answer 11

Axillary nerve (C5-C6)

Question 12

Deltoid-Anterior (action)

Answer 12

Flexes and Medially Rotates arm

*Whole muscle: resist inferior displacement of humeral head

Question 13

Deltoid-Middle (attachment)

Answer 13

Acromion of scapula AND deltoid tuberosity of humerus

Question 14

Deltoid-Middle (innervation)

Answer 14

Axillary nerve (C5-C6)

Question 15

Deltoid-Middle (action)

Answer 15

ABducts arm

*Whole muscle: resist inferior displacement of humeral head

Question 16

Deltoid-Posterior (attachment)

Answer 16

Spine of scapula AND deltoid tuberosity of humerus

Question 17

Deltoid-Posterior (innervation)

Answer 17

Axillary nerve (C5-C6)

Question 18

Deltoid-Posterior (action)

Answer 18

Extends and Laterally rotates arm

*Whole muscle: resists inferior displacement of humerus

Question 19

Supraspinatus (attachment)

Answer 19

Supraspinous fossa of scapula AND greater tubercle of humerus

Question 20

Supraspinatus (innervation)

Answer 20

Suprascapular nerve (C4-C6)

Question 21

Supraspinatus (action)

Answer 21

ABducts arm (initiates abduction-first 15 degrees)
*As part of rotator cuff: holds humeral head in glenoid cavity

Question 22

Infraspinatus (attachment)

Answer 22

Infraspinous fossa of scapula AND greater tubercle of humerus

Question 23

Infraspinatus (innervation)

Answer 23

Suprascapular nerve (C5-C6)

Question 24

Infraspinatus (action)

Answer 24

Laterally rotates arm

*As part of rotator cuff: holds humeral head in glenoid cavity

Question 25

Teres major (attachment)

Answer 25

Inferior angle of scapula AND bicipital groove of humerus

Question 26

Teres major (innervation)

Answer 26

Lower subscapular nerve (C5-C6)

Question 27

Teres major (action)

Answer 27

ADducts and medially rotates arm

Question 28

Teres minor (attachment)

Answer 28

Lateral border of scapula AND greater tubercle of humerus

Question 29

Teres minor (innervation)

Answer 29

Axillary nerve (C5-C6)

Question 30

Teres minor (action)

Answer 30

Laterally rotates arm

*As part of rotator cuff: holds humeral head in glenoid cavity

Question 31

Triceps brachii (attachment)

Answer 31

Long head: infraglenoid tubercle of scapula AND olecranon process of ulna
Lateral head: posterior surface of humerus AND olecranon process of ulna
Medial head: posterior surface of humerus AND olecranon process of ulna

Question 32

Triceps brachii (innervation)

Answer 32

Radial nerve (C6-C8)

Question 33

Triceps brachii (action)

Answer 33

Extends forearm

**Long head: extends and ADducts arm AND resists inferior displacement of the head of the humerus