Physio Review

Question 1

How can we calculate the O2 in the alveoli?

Answer 1

PAO2= PiO2-(PaCO2/R)

Question 2

What is PiO2

Answer 2

the amount of inspired O2

Question 3

How do we calculate PiO2

Answer 3

[Patm-47]*O2 capacity Ex (167mmHg-47)*.21

Question 4

Oncre we have the PAO2, what do we do.

Answer 4

Take the A-aO2 gradient, to tell us if there is a diffusion problm. Subtract the alveolar O2 we solved from the arterial O2. If the answer is <12, there is not a diffusion problem.

Question 5

Respiratory alkalosis in acute and chronic

Answer 5

acute expected[HCO3]=24-2((40-PaCO2)/10)) Chronic use 5 instead of 2

Question 6

What stimulates our peripheral chemoreceptors

Answer 6

decrease in O2 Increase in CO2 Increase in H Hypoxia and hypercapnia

Question 7

What do peripheral CR do?

Answer 7

Increase frequency if breathing (f) Increase tidal volume

Question 8

What structures will be affected by an activation of perhpheral CR

Answer 8

frequency- Pre-botzinger Tidal volume- DRG

Question 9

If we increase f and tidal volume, what we are doing?

Answer 9

Increasing minute ventillation Thus, WE ARE HYPERVENTILLATING. =increase in PaO2 and decrease in PaCO2;

Question 10

What is the flat line of the Hb-02 curve?

Answer 10

Safety margin. Given a large change in partial pressure of O2, we have a small change in our O2 saturation

Question 11

What will happen when moving from a seated position to supine in a normal person?

Answer 11

Decrease in TLC

Decrease in ERV

Increase in IRV

RV does not change

Question 12

What will happen when moving from a seated position to supine in a obsese person?

Answer 12

Decrease in TLC

Decrease in IRV

No change in ERV

Question 13

What changes in response to body positioning?

Answer 13

TLC

Question 14

What changes will you see in obstructive diseases?

Answer 14

Increase in TLC and RV

Decrease in FEV1

Decrease in FEV1/FVC

Question 15

Restrictive DZ

• FVC
• FEV1
• FEV1/FVC ratio
• TLC

Answer 15

• FVC- decreased
• FEV1- decreased
• FEV1/FVC ratio- normal or high (80% or more)
• TLC- decreased

Question 16

In an obstructive lung disease, how would compliance and elasticity be affected?

Answer 16

increase compliance

decrease elasticity

Question 17

COPD is obstructive. Why would there be less O2 diffusion?

Answer 17

decrease in SA

Question 18

Fibrosis is restrictive. Why would there be less O2 diffusion?

Answer 18

Increase in thickness of traveling diameter

Question 19

In restrictive diseases, what happens to compliance and elasticity

Answer 19

Decrease in compliance

Increase in elasticity

Question 20

what happens during a pneumothorax

Answer 20

• Blood will shunt to the lung that is not collapsed (via NO)
• Blood will stop going to collapsed lung (vasoconstriction via thromboxane 2 and endothelin 1)

Question 21

Oxygen in the alveoli

Answer 21

PAO2= PiO2- PaCO2/R

Question 22

PiO2

Answer 22

(Patm- 47) * oxygen capacity (ex.21)

Question 23

RQ for infusion with glucose

Answer 23

1

Question 24

RQ for infusion with fats

Answer 24

0.7

Question 25

RQ during fasting

Answer 25

0.7

Question 26

RQ furing a hard run

Answer 26

increases

Question 27

Always assume RQ is

Answer 27

.8

Question 28

What happens to the resistance to blood flow when we get closes to FRC?

Answer 28

Resistance is lowest.

As you move to TLC or RV, resistance INCREASES

Question 29

Zone 1

Alveolar ventilation- higher or lower

V/Q- higher or lower

PaO2- high or lower

PaCO2- higher or lower

Answer 29

Alveolar ventilation- higher or lower

V/Q- higher or lower

PaO2- high or lower

PaCO2- higher or lower

Question 30

which receptors help us maintain a sleeping/resting state

Answer 30

CENTRAL CHEMORECEPTORS

-pH of the CSF-

Question 31

What happens during a pulmonary thromboembolism?

Answer 31

results in areas of the lung that are ventilated, but not perfused, causing VQ ratio to go to infinity and increase alveolar dead space.

PaO2 of the affected alveoli will be the same as the inspired air via ventilation cuz no gas exchange occurs.

Question 32

What happens to areas fof the lung that are perfused, but not ventilated?

Answer 32

Constitute areas of shunting (venous admixture)

Characterized as a V/Q ratio equal to 0 and having a PAO2 value that equillibriutes with mixed venous blood