Thorax 1 - Anterior Thoracic Wall and Lungs

Question 1

What is the origin and insertion of pec major?

Answer 1

O - clavicle, ribs, sternum

I - humerus

Question 2

What is the action and innervation of pec major?

Answer 2

A - flexes arm, adducts and medially rotates at the shoulder

I - medial and lateral pectoral nerves

Question 3

What is the origin and insertion of pec minor?

Answer 3

O - Ribs III to V

I - coracoid of scapula

Question 4

What is the action and innervation of pec minor?

Answer 4

A - protract and depress the scapula

I - medial pectoral nerve

Question 5

What is the origin and insertion of serratus anterior?

Answer 5

O - lateral surface of upper ribs

I - medial border of scapula

Question 6

What is the action and innervation of serratus anterior?

Answer 6

A - protracts and holds the scapula against the thoracic wall; raise arm past 90 degrees
I - long thoracic nerve

Question 7

What is the origin and insertion of serratus posterior superior?

Answer 7

O - vertebrae C VII to T III

I - Ribs II to V

Question 8

What is the action and innervation of serratus posterior superior?

Answer 8

A - elevates ribs during inhalation

I - spinal nerves

Question 9

What is the origin and insertion of serratus posterior inferior?

Answer 9

O - Vertebrae T XI to L III

I - Ribs IX to XII

Question 10

What is the action and innervation of serratus posterior inferior?

Answer 10

A - depress ribs during exhalation

I - spinal nerves

Question 11

What is the origin and insertion of external intercostals?

Answer 11

O - inferior border of superior rib

I - superior border of inferior rib

Question 12

What is the action and innervation of external intercostals?

Answer 12

A - elevates ribs to increase the dimensions of the thorax

I - intercostal nerves

Question 13

What is the origin and insertion of internal intercostals?

Answer 13

O - superior border of inferior rib

I - inferior border of superior rib

Question 14

What is the action and innervation of internal intercostals?

Answer 14

A - moves adjacent ribs together to decrease the dimensions of the thorax
I - intercostal nerves

Question 15

What is the origin and insertion of the innermost intercostals?

Answer 15

O - superior border of inferior rib

I - inferior border of superior rib

Question 16

What is the action and innervation of the innermost intercostals?

Answer 16

A - works with the internal intercostals

I - intercostal nerves

Question 17

What is the origin and insertion of the diaphragm?

Answer 17

O - xiphoid of sternum, costal cartilages, lumbar vertebrae and their discs
I - central tendon

Question 18

What is the action and innervation of the diaphragm?

Answer 18

A - contraction causes it to flatten and increase the dimensions of the thorax; relaxation moves it superiorly to decrease the dimensions of the thorax
I - phrenic nerve

Question 19

What is the origin and insertion of transversus thoracis?

Answer 19

O - ribs II to VI

I - costal cartilages and sternum

Question 20

What is the action and innervation of transversus thoracis?

Answer 20

A - depress costal cartilage

I - intercostal nerves