O & I Shoulder, Posterior arm, & Pectoral Region

Question 1

Origin: Pectoralis Major

Answer 1

Clavicular Head: anterior surface of medial half of clavicle

Sternocostal Head: anterior surface of sternum, superior six costal cartilages, and aponeurosis of external oblique muscle

Question 2

Insertion: Pectoralis Major

Answer 2

Lateral lip of inter tubercular sulcus of humerus

Question 3

Innervation: Pectoralis Major

Answer 3

Lateral and medial pectoral nerves; Clavicular head (C5,C6), and Sternocostal head (C7, C8, T1)

Question 4

Action: Pectoralis Major

Answer 4

Adducts and medially rotates humerus; draws the scapula anteriorly and inferiorly.

Acting alone, the clavicular head flexes the humerus and the sternocostal head extends the humerus from a flexed position

Question 5

Origin: Pectoralis Minor

Answer 5

3rd - 5th ribs near their costal cartilages

Question 6

Insertion: Pectoralis Minor

Answer 6

Medial boarder and superior surface of coracoid process of scapula

Question 7

Innervation: Pectoralis Minor

Answer 7

Medial Pectoral Nerve (C8, T1)

Question 8

Action: Pectoralis Minor

Answer 8

Stabilizes the scapula by drawing it inferiorly and anteriorly against thoracic wall

Question 9

Origin: Subclavius

Answer 9

Junction of 1st rib and its costal cartilage

Question 10

Insertion: Subclavius

Answer 10

Inferior surface of middle third of clavicle

Question 11

Innervation: Subclavius

Answer 11

Nerve to subclavius (C5,C6)

Question 12

Action: Subclavius

Answer 12

Anchors and depresses clavicle

Question 13

Origin: Serratus Anterior

Answer 13

External surfaces of lateral parts of 1st - 8th ribs

Question 14

Insertion: Serratus Anterior

Answer 14

Anterior surface of medial border of scapula

Question 15

Innervation: Serratus Anterior

Answer 15

Long Thoracic Nerve (C5, C6, C7)

Question 16

Action: Serratus Anterior

Answer 16

Protracts the scapula and holds it against thoracic wall; rotates scapula

Question 17

Origin: Deltoid

Answer 17

Lateral 1/3 of clavicle; acrominon and spine of scapula

Question 18

Insertion: Deltoid

Answer 18

Deltoid tuberosity of humerus

Question 19

Innervation: Deltoid

Answer 19

Axillary nerve (C5, C6)

Question 20

Action: Deltoid

Answer 20

Clavicular (anterior) part: flexes & medially (internally) rotates arm

Acromial (medial) part: abducts arm

Spinal (posterior) part: extends & laterally (externally) rotates arm

Question 21

Origin: Teres Major

Answer 21

Posterior surface of inferior angle of the scapula

Question 22

Insertion: Teres Major

Answer 22

Medial lip of inter tubercular sulcus of humerus

Question 23

Innervation: Teres Major

Answer 23

Lower Subscapular nerve (C5, C6)

Question 24

Action: Teres Major

Answer 24

Adducts & medially (internally) rotates arm

Question 25

Origin: Subscapularis

Answer 25

Subscapular fossa (most of the anterior surface of the scapula)

Question 26

Insertion: Subscapularis

Answer 26

Lesser tubercle of humerus

Question 27

Innervation: Subscapularis

Answer 27

Upper and lower subscapular nerves (C5, C6, C7)

Question 28

Action: Subscapularis

Answer 28

Medially rotates arm As part of rotator cuff, helps hold head of humerus in glenoid cavity

Question 29

Origin: Supraspinatus

Answer 29

Supraspinous fossa of scapula

Question 30

Insertion: Supraspinatus

Answer 30

Superior facet of greater tubercle of humerus

Question 31

Innervation: Supraspinatus

Answer 31

Suprascapular nerve (C4, C5, C6)

Question 32

Action: Supraspinatus

Answer 32

Initiates and assist deltoid /c abduction of arm Acts /c rotator cuff muscles to help hold head of humerus in glenoid cavity

Question 33

Origin: Infraspinatus

Answer 33

Infraspinous fossa of scapula

Question 34

Insertion: Infraspinatus

Answer 34

Middle facet of greater tubercle of humerus

Question 35

Innervation: Infraspinatus

Answer 35

Suprascapular Nerve (C5, C6)

Question 36

Action: Infraspinatus

Answer 36

Laterally rotates arm Acts /c other rotator cuff muscles to help hold head of humerus in glenoid cavity

Question 37

Origin: Teres Minor

Answer 37

Middle part of lateral border of scapula

Question 38

Insertion: Teres Minor

Answer 38

Inferior facet of greater tubercle of humerus

Question 39

Innervation: Teres Minor

Answer 39

Axillary nerve (C5, C6)

Question 40

Action: Teres Minor

Answer 40

Laterally rotates arm Acts /c other rotator cuff muscles to help hold head of humerus in glenoid cavity

Question 41

Origin: Triceps Brachii

Answer 41

Long Head: infraglenoid tubercle of scapula Lateral Head: posterior surface of humerus, superior to radial groove Medial Head: posterior surface of humerus, inferior to radial groove

Question 42

Insertion: Triceps Brachii

Answer 42

Proximal end of olecranon of ulna and fascia of forearm

Question 43

Innervation: Triceps Brachii

Answer 43

radial nerve (C6, C7, C8)

Question 44

Action: Triceps Brachii

Answer 44

Chief extensor of forearm; long head resists dislocation of humerus; especially important during adduction

Question 45

Origin: Platysma

Answer 45

Subcutaneous tissue of infraclavicular and supraclavicular regions

Question 46

Insertion: Platysma

Answer 46

Base of mandible; skin of cheek and lower lip; angle of mouth (modiolus); orbicularis oris

Question 47

Innervation: Platysma

Answer 47

Cervical branch of the facial n. (CN VII)

Question 48

Action: Platysma

Answer 48

Depresses mandible (against resistance); tenses skin of inferior face and neck (conveying tension and stress)