Respiratory Mechanics

Question 1

what is the muscle of quiet breathing?

Answer 1

diaphragm

Question 2

during inspiration, the diaphragm ____

Answer 2

contracts

Question 3

during expiration, the diaphragm ____

Answer 3

relaxes

Question 4

what are the muscles of forced inspiration (extra respiratory drive)?

Answer 4

• external intercostals
• SCM
• scalenes
• serratus anterior

Question 5

what are the muscles of forced expiration (extra respiratory drive)?

Answer 5

• internal intercostals
• abdominals

Question 6

what muscle is most effective at producing maximal effort?

Answer 6

Rectus abdominis

Question 7

what do the external intercostals do?

Answer 7

elevate the ribs for inspiration

Question 8

what do the internal intercostals do?

Answer 8

depress the ribs during expiration

Question 9

what effect does sympathetic stimulation have on the lungs?

Answer 9

dilates bronchi

Question 10

what NT is released at sympathetic nerve endings at the lungs?

Answer 10

NE/E

Question 11

what receptor do NT of sympathetic nerve endings at the lungs act on?

Answer 11

beta adrenergic

Question 12

what effect does parasympathetic stimulation have on the lungs?

Answer 12

constricts bronchi

Question 13

what NT is released at parasympathetic nerve endings at the lungs?

Answer 13

ACh

Question 14

what receptor do NT of parasympathetic nerve endings at the lungs act on?

Answer 14

muscarinic (lung parenchyma)

Question 15

what is the alveolar pressure at the beginning of inspiration?

Answer 15

0

Question 16

what is the alveolar pressure during inspiration?

Answer 16

-1

Question 17

what is the alveolar pressure at the end of inspiration?

Answer 17

0

Question 18

what is the alveolar pressure during expiration?

Answer 18

+1

Question 19

what is the alveolar pressure at the end of expiration?

Answer 19

0

Question 20

what is the plural pressure at the beginning of inspiration?

Answer 20

-5

Question 21

what is the plural pressure at the end of inspiration?

Answer 21

-8

Question 22

what is the plural pressure at the end of expiration?

Answer 22

-5

Question 23

what is the transpulmonary pressure at the beginning of inspiration?

Answer 23

+5

Question 24

what is the transpulmonary pressure at the end of inspiration?

Answer 24

+8

Question 25

what is the transpulmonary pressure at the end of expiration?

Answer 25

+5

Question 26

what is compliance?

Answer 26

ability of the lung to expand

Question 27

what increases compliance?

Answer 27

decreased surface tension

Question 28

what is responsible for 2/3 of the ability to reduce surface tension?

Answer 28

pulmonary surfactant

Question 29

what cells make surfactant?

Answer 29

type II alveolar cells

Question 30

what is the biochemical name of surfactant?

Answer 30

dipalmitoyl phosphatidyl choline

Question 31

surfactant also contains ____ and ____

Answer 31

apoproteins
Ca++ ions

Question 32

in a preterm infant without pulmonary surfactant, what changes occur to alveolar surface tension and pulmonary compliance compared to a normal infant?

Answer 32

• alveolar surface tension increases
• compliance decreases

Question 33

what changes occur to lung compliance and surfactant levels in a premature infant with respiratory distress syndrome?

Answer 33

• decreased compliance
• decreased surfactant