Physical Aspects of Breathing

Question 1

what is the respiratory quotient?

Answer 1

co2 produced over oxygen consumed

Question 2

what is the respiratory quotient on carb diet?

Answer 2

1.0

Question 3

what is the respiartory quotient for fat diet?

Answer 3

0.7

Question 4

what is the respiratory quotient for mixed carb and fat diet?

Answer 4

0.8

Question 5

what is the partial pressure of oxygen and percent oxygen in dry air?

Answer 5

160 or 21%

Question 6

what is the partial pressure of oxygen in moist tracheal gas? explain this

Answer 6

150…lower because of presence of water in air takes away place for oxygen so taking 21% of smaller number

Question 7

what is the partial pressure of oxygen in alveoli? explain

Answer 7

104 mmHg about…this is because you are getting higher amounts of CO2 so less space for O2 to reside…drives it down…H20 still present too

Question 8

what is the partial pressure of carbon dioxide in the alveoli?

Answer 8

40 mmHg

Question 9

what does it mean for the conducting zone to be an anatomic dead space?

Answer 9

it means it cannot contribute to gas exchange

Question 10

does cross sectional area increase or decrease as you move down the respiratory tract?

Answer 10

Def increases

Question 11

explain how air comes into the lungs using boyles law?

Answer 11

pressureXvolume=constant….so as you increase volume pressure drops and air flows in

Question 12

is there a negative or positive pressure in the intrapleural space?

Answer 12

negative pressure…

Question 13

why is there negative pressure in the pleural space?

Answer 13

because the fluid lubricating the space creates a vacuum with the two layers trying to pull apart…visceral pulling in as lung wants to collapse and chest parietal layer wants to expand

Question 14

is a highly compliant lung floppy or stiff?

Answer 14

floppy

Question 15

is a high elastance lung floppy or stiff?

Answer 15

stiff

Question 16

what process drives expiration?

Answer 16

passive elastic recoil of the lungs

Question 17

if you need to know the residual volume of someones lungs, what test can you do?

Answer 17

body plethysmograph

Question 18

what are the three categories of lung disease?

Answer 18

developmental
restrictive
obstructive

Question 19

is CF an obstructive or restrictive lung disease?

Answer 19

obstructive

Question 20

is emphysema an obstructive or restrictive disease?

Answer 20

obstructive

Question 21

what is the intrapleural pressure at the end of expiration?

Answer 21

-5 cmH20

Question 22

what is the intrapleural pressure during inspiration?

Answer 22

-8 cmH20

Question 23

why does the intrapleural pressure drop more during inspiration?

Answer 23

because the respiratory muscles are pulling the chest wall out and lung still has recoil force…so creates bigger vacuum

Question 24

how do you calculate the transmural or transpulmonary pressure?

Answer 24

alveolar pressure minus the intrepleural pressure

Question 25

mathematically define the compliance of a lung

Answer 25

change in volume over change in pressure

Question 26

how does elastance of a lung relate to compliance of a lung?

Answer 26

elastance is the mathematical inverse of the compliance of the lung

Question 27

define the inspiratory reserve volume

Answer 27

volume of air you can add in addition to a normal breath

Question 28

define tidal volume

Answer 28

volume of normal breath

Question 29

define expiratory reserve volume

Answer 29

volume of air that can be forced out with a hard force

Question 30

define residual volume

Answer 30

volume of air left in lungs after the expiratory reserve volume has been pushed out

Question 31

name the three lung volumes that add up to vital capacity

Answer 31

expiratory reserve
tidal
inspiratory reserve

Question 32

name the four lung volumes that add up to total lung capacity

Answer 32

tidal
expiratory reserve
inspiratory reserve
residual

Question 33

name the two lung volumes that add up to inspiratory capacity

Answer 33

tidal

inspiratory reserve

Question 34

name the two lung volumes that add up to functional residual capacity

Answer 34

expiratory reserve

residual volume

Question 35

describe restrictive lung disease in terms of elastance or compliance

Answer 35

restrictive lung disease is seen in lungs that have very high elastance, or very low compliance

Question 36

describe obstructive lung disease in terms of elastance or compliance

Answer 36

obstructive lung disease is seen in lungs with very low elastance or very high compliance

Question 37

what is normal ABG for oxygen?

Answer 37

80-100 mmHg

Question 38

what is normal ABG for CO2?

Answer 38

35-45 mmHg