Thorax

Question 1

Pectoralis Major Orgin

Answer 1

Clavicular Head:anterior surface of medial half of clavicle

Sternocostal Head: anterior surface of sternum, costal cartilages of ribs 1-6 and aponeurosis of external oblique mm.

Question 2

Pec Major Insertion

Answer 2

Lateral lip of the intertubercular suluc on humerus

Question 3

Pec major Innervation

Answer 3

Lateral and Medial Pectoral N. (CH: C5,C6/ SH: C7-T1)

Question 4

Pec Major Action

Answer 4

Adducts and medially rotates humerus , draws scapula anteriorly and inferiorly. Acting alone the CH flexes the humerus and the SH extends it from the flexed position

Question 5

Pec Minor Orgin

Answer 5

ribs 3-5 near their costal cartilages

Question 6

Pec Minor Insertion

Answer 6

medial and superior surface of the coracoid process of the scpaula

Question 7

Pec Minor Innevation

Answer 7

Medial Pectoral N (C8, T1)

Question 8

Pec Minor Action

Answer 8

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

Question 9

External Intercostal Origin

Answer 9

Inferior Borders of the ribs, run INFEROANTERIORLY between successive ribs between the tubercles and costochondral junctions

Question 10

External Intercostal insertion

Answer 10

superior borders of the ribs between the tubercles and costochondral junctions

Question 11

External Intercostal Innervation

Answer 11

Intercostal Nerve

Question 12

External Intercostal Action

Answer 12

most active during INSPIRATION maintaining the tone of the muscles in the intercostal space and ELEVATING the ribs during forced inspiration.

Question 13

Internal Intercostal Origin

Answer 13

Inferior Borders of the ribs, run deep and INFEROPOSTERIORLY from rib angle to sternum

Question 14

Internal Intercostal Insertion

Answer 14

superior borders of ribs from rib angle to sternum

Question 15

Internal Intercostal innervation

Answer 15

Intercostal nerve

Question 16

Internal Intercostal Action

Answer 16

most active during EXPIRATION, maintaining the tone of the intercostal space. During forced expiration, Interosseous part depress ribs, Interchondral part elevates ribs

Question 17

Innermost Intercostal Origin

Answer 17

inferior border of ribs

Question 18

Innermost Intercostal Insertion

Answer 18

superior border of ribs

Question 19

Innermost Intercostal Innervation

Answer 19

Intercostal N.

Question 20

Innermost Intercotal Action

Answer 20

most active during EXPIRATION, maintaining the tone of the intercostal space. During forced expiration, Interosseous part depress ribs, Interchondral part elevates ribs

Question 21

Subcostal Origin

Answer 21

Internal surface of lower ribs near their angles

Question 22

Subcostal Insertion

Answer 22

Superior borders of 2nd or 3rd rib below (spans 2-3 ribs)

Question 23

Subcostal Innervation

Answer 23

Intercostal N.

Question 24

Subcostal Action

Answer 24

prob same as Internal Intercostal; help to maintain tone in expiration and depress ribs in forced exipration

Question 25

Transversus Thoracis Origin

Answer 25

Posterior Surface of lower Sternum ( body and Xiphoid process)

Question 26

Tranversus Thoracis Insertion

Answer 26

internal surface of costal cartilages of ribs 2-6

Question 27

Transversus Thoracis Innervation

Answer 27

Intercostal N

Question 28

Transversus Thoracis Action

Answer 28

weakly depresses ribs and proprioception