Chest Musculature

Question 1

Pectoralis Major Prox and Distal attachment

Answer 1

Proximal: Medial clavical, Sternum, Costal cartilages 1-6, Rectus sheath

Distal: greater tuberosity of the humerus

Question 2

Pectoralis minor prox and dist attachment

Answer 2

Prox: Ribs 3-5

Distal: Coracoid process (scapula)

Question 3

Subclavius prox and distal attachment

Answer 3

Proximal: 1st rib

Distal: inferior clavicle

Question 4

Pec Major Action

Answer 4

Adduction; medial rotation; flexion; respiratory assistance when shoulder is fixed

Question 5

Pec Minor Action

Answer 5

Draws scap downward; rotates glenoid inferiorly; assists in respirateion

Question 6

Subclavius action

Answer 6

Steadies sternoclavian joint

Question 7

Pec Major innervation

Answer 7

Medial and lateral pectoral nn (C8, T1 med) (C5-7 lat)

Question 8

Pec minor innervation

Answer 8

Medial pectoral nerve (C8, T1)

Question 9

Subclavius innervation

Answer 9

Nerve to subclavius (C5,C6)

Question 10

Pec major supply

Answer 10

Thoracoacromial a. (Pectoral branch), lateral thoracic a.

Question 11

Pec minor supply

Answer 11

Thoracoacromial a. (Pectoral branch), and lateral thoracic a.

Question 12

Subclavian supply

Answer 12

Thoracoacromial a. (Clavicular br.)

Question 13

External intercostal prox/dist attachment

Answer 13

Prox: courses inferioanteriorly from rib’s tubercle to costochondral joint

Dist: ditto

Question 14

Internal intercostal prox/dist attach

Answer 14

Prox and distal: courses supers-anteriorly from costal angle to sternum

Question 15

Innermost intercostal prox and dist

Answer 15

From lower margin of rib to inner surface of ribs 2-3 below (fibers blend with innermost costal)

Question 16

Transverse thoracis prox and dist

Answer 16

Inner surface of the sternum

Question 17

Ext. intercostal action

Answer 17

Elevation of ribs (inspiration)

Question 18

Int. Intercostal action

Answer 18

Interosseous component: depresses ribs during expiration

Interchondral component: elevates costal cartilages during inspiration

Question 19

Innermost intercostal action

Answer 19

Depresses ribs during expiration

Question 20

Subcostal action

Answer 20

Depresses ribs during expiration

Question 21

Transversus thoracis

Answer 21

Weakly depresses ribs during expiration

Question 22

Ext. intercostal innervation

Answer 22

Intercostal nerves 1-11 (ant rami thoracic spinal nn.)

Question 23

Int. Intercostal innervation

Answer 23

Intercostal nerves 1-11 (ant rami of thoracic nn)

Question 24

Innermost intercostal innervation

Answer 24

12 thoracic nn.

Question 25

Transversus thoracis innervation

Answer 25

2-6 thoracic spinal nn.

Question 26

Ext. intercostal supply

Answer 26

Intercostal aa.

Question 27

Int. Intercostal supply

Answer 27

Intercostal aa.

Question 28

Innermost intercostal supply

Answer 28

Intercostal aa.

Question 29

Subcostal supply

Answer 29

Subcostal a.

Question 30

Transversus thoracis supply

Answer 30

Intercostal aa.