Unit 2 - Chest + Upper Arm

Question 1

Origin (prox. attachment) – surpaspinatus m.

Answer 1

supraspinous fossa of scapula

Question 2

Insertion (dist. attachment) – supraspinatus m.

Answer 2

superior facet of greater tubercle of humerus

Question 3

Innervation – supraspinatus m.

Answer 3

suprascapular n. (C4, C5, C6)

Question 4

Action – supraspinatus m.

Answer 4

• initiates & helps deltoid abduct shoulder joint
• acts w/ other rotator cuff muscles

Question 5

Origin (prox. attachment) – infraspinatus m.

Answer 5

infraspinous fossa of scapula

Question 6

Insertion (dist. attachment) – infraspinatus m.

Answer 6

middle facet of greater tubercle of humerus

Question 7

Innervation – infraspinatus m.

Answer 7

suprascapular nerve (C5, C6)

Question 8

Action – infraspinatus m.

Answer 8

• laterally rotates arm
• acts w/ other rotator cuff muscles

Question 9

Origin (prox. attachment) – teres major m.

Answer 9

posterior surface of inferior angle of scapula

Question 10

Insertion (dist. attachment) – teres major m.

Answer 10

medial lip of intertubercular sulcus of humerus

Question 11

Innervation – teres major m.

Answer 11

lower subscapular n. (C5, C6)

Question 12

Action – teres major m.

Answer 12

adducts & medially rotates arm

Question 13

Origin (prox. attachment) – teres minor m.

Answer 13

middle part of lateral border of scapula

Question 14

Insertion (dist. attachment) – teres minor m.

Answer 14

inferior facet of greater tubercle of humerus

Question 15

Innervation – teres minor m.

Answer 15

axillary n. (C5, C6)

Question 16

Action – teres minor m.

Answer 16

laterally rotates arm
- rotator cuff muscle

Question 17

Origin (prox. attachment) – pectoralis major m.

Answer 17

• clavicular head = anterior surface, medial half of clavicle
• sternocostal head =
• anterior surface of sternum
• superior 6 costal cartilage
• aponeurosis of external oblique

Question 18

Insertion (dist. attachment) – pectoralis major m.

Answer 18

lateral lip of intertubercular sulcus of humerus

Question 19

Innervation – pectoralis major m.

Answer 19

lateral & medial pectoral nerves

clavicular head = C5 and C6
sternocostal head = C7, C8, T1

Question 20

Action – pectoralis major m.

Answer 20

• adducts & medially rotates humerus
• draws scapula anteriorly and inferiorly
• Alone = [clavicular] flexes humerus; [sternocostal] extends humerus

Question 21

Origin (prox. attachment) – pectoralis minor m.

Answer 21

3rd - 5th ribs near costal cartilages

Question 22

Insertion (dist. attachment) – pectoralis minor m.

Answer 22

medial border & superior surface of coracoid process of scapula

Question 23

Innervation – pectoralis minor m.

Answer 23

medial pectoral n. (C8, T1)

Question 24

Action – pectoralis minor m.

Answer 24

• draws scapula inferiorly and anteriorly against thoracic wall = stabilizes scapula

Question 25

Origin (prox. attachment) -- serratus anterior m.

Answer 25

lateral external surfaces of 1st - 8th ribs

Question 26

Insertion (dist. attachment) -- serratus anterior m.

Answer 26

anterior surface medial border of scapular

Question 27

Innervation -- serratus anterior m.

Answer 27

long thoracic n. (C5, C6, C7)

Question 28

Action -- serratus anterior m.

Answer 28

* protracts scapula * holds it against thoracic wall * rotates scapula

Question 29

Origin (prox. attachment) -- deltoid m.

Answer 29

lateral third of clavicle; acromion and spine of scapula

Question 30

Insertion (dist. attachment) -- deltoid m.

Answer 30

deltoid tuberosity of humerus

Question 31

Innervation -- deltoid m.

Answer 31

axillary n. (C5, C6)

Question 32

Action -- deltoid m.

Answer 32

* clavicular = flexes & medially rotates arm * acromial = abducts arm * spinal = extends and laterally rotates arm

Question 33

Origin (prox. attachment) -- subscapularis m.

Answer 33

subscapular fossa

Question 34

Insertion (dist. attachment) -- subscapularis m.

Answer 34

lesser tubercle of humerus

Question 35

Innervation -- subscapularis m.

Answer 35

upper and lower subscapular n. (C5, C6, C7)

Question 36

Action -- subscapularis m.

Answer 36

* medially rotates arm * rotator cuff muscle * helps hold head of humerus in glenoid cavity

Question 37

Innervation -- coracobrachialis m.

Answer 37

musculocutaneous n. (C5, C6, C7)

Question 38

Action -- coracobrachialis m.

Answer 38

helps flex & adduct arm * resists shoulder dislocation

Question 39

Origin (prox. attachment) -- biceps brachii m.

Answer 39

* short head = tip of coracoid process of scapula * long head = supraglenoid tubercle of scapula

Question 40

Insertion (dist. attachment) -- biceps brachii m.

Answer 40

radial tuberosity and fascia of forearm via bicipital aponeurosis

Question 41

Innervation -- biceps brachii m.

Answer 41

musculocutaneous n. (C5, C6, C7)

Question 42

Action -- biceps brachii m.

Answer 42

* supinates forearm * flexes forearm in supine * short head = resists shoulder dislocation

Question 43

Origin (prox. attachments) -- brachialis m.

Answer 43

distal 1/2 of anterior surface of humerus

Question 44

Insertion (dist. attachment) -- brachialis m.

Answer 44

coronoid process & tuberosity of ulna

Question 45

Innervation -- brachialis m.

Answer 45

musculocutaneous n. ; radial n. (C5 and C7)

Question 46

Action -- brachialis m.

Answer 46

flexes forearm in all positions

Question 47

Origin (prox. attachment) -- brachioradialis m.

Answer 47

proximal 2/3 of lateral supracondylar ridge of humerus

Question 48

Insertion (dist. attachment) -- brachioradialis m.

Answer 48

lateral surface of distal end of radius; proximal to styloid process

Question 49

Innervation -- brachioradialis m.

Answer 49

radial n. (C5, C6, C7)

Question 50

Action -- brachioradialis m.

Answer 50

* relatively weak elbow joint flexion * maximal when forearm is midpronated position

Question 51

Origin (prox. attachment) -- triceps brachii m.

Answer 51

Long head = infraglenoid tubercle of scapula Lateral head = posterior surface of humerus, superior to radial groove

Question 52

Insertion (dist. attachment) -- triceps brachii m.

Answer 52

* Proximal end of olecranon of ulna * forearm fascia

Question 53

Innervation -- triceps brachii m.

Answer 53

radial n. (C6, C7, C8)

Question 54

Action -- triceps brachii m.

Answer 54

* chief extensor of elbow joint * long head = extends shoulder joint, resists humerus dislocation

Question 55

Innervation -- anconeus m.

Answer 55

Radial n. (C7, C8, T1)

Question 56

Action -- anconeus m.

Answer 56

* helps triceps in extending elbow joint * stabilizes elbow joint * abduct ulna during pronation