resp 3

Question 1

what is pulmonary edema?

Answer 1

the alveoli become filled with fluid so gas exchange cannot occur since fluid displaces the air

Question 2

what is interstitial fibrosis?

Answer 2

the alevoli become inflammed and scar tissue forms in the interstisial layers of the alveolar walls. the thicker wall makes diffusion more difficult

Question 3

dissolved oxygen represents what percent of all the oxygen?

Answer 3

less than 1%. nearly all oxygen is carried by hemoglobin

Question 4

when hemoglobin combines with oxygen it turns ___ and becomes ____

when hemoglobin releases oxygen it turns ___ and becomes ____

Answer 4

red, oxuhemoglobin

purple, deoxyhemoglobin

Question 5

what is the % saturation?

Answer 5

is the % of all the hemoglobin that are bound to an oxygen

Question 6

each hemoglobin can carry __ oxygen molecules

Answer 6

4

Question 7

the relationship between saturation and partial pressure is ____. what are two advantages of this?

Answer 7

NOT LINEAR, it is an S curve

you want to load at the level of the lungs and unload at the level of the tissues

1. at the flat portion, above 60, there isn’t much change in the hemoglobin saturation and this is important for loading at the level of the lungs
2. at the steep portion the hemoglobin saturation changes a lot fo this favors unloading in the tissues

Question 8

a right shift in the S curve _____ the affinity for oxygen. this occurs with__

this occurs at the level of the ____

Answer 8

decreases

increased temperature and decreases in pH

tissues

Question 9

a left shift in the S curve _____ affinity for oxygen. occurs with:

this occurs at the level of the

Answer 9

increases

decrease in temperature and increases in pH

lungs

Question 10

oxygen uptake refers to:

oxygen content refers to:

oxygen delivery refers to:

Answer 10

how much is there in the alveolus?

how much oxygen is in the arterial blood

blood flow is needed to move blood to deliver oxygen to tissues

Question 11

the alveolar gas equation is: PAO2=FiO2 x (pB - PH2O) - (PaCO2/0.8)

what are each of the variables?

PAO2 should be around what at sea level?

what is the shortcut for calculating it?

Answer 11

FiO2= fraction of inspired oxygen

PB= barometric pressure, usually 760

PH2O=water vapour pressure, usually 47 at normal body temp

0.8 is the respiratory quotient

PaCO2 is partial pressure of CO2, usually 40

100mmHg

multiply the % inspired O2 by 5

Question 12

hypoxemia refers to:

Hypoxia refers to:

Answer 12

the oxygen saturation of arterial blood is low

when oxygen levels are low at the tissues themselves

Question 13

5 causes of hypoxemia?

Answer 13

1. low inspired oxygen
2. hypoventilation
3. diffusion impairment
4. ventilation/perfusion mismatch
5. right to left shunt

Question 14

the A-a gradient is used to

what is the equation

Answer 14

asses the differences between the oxygen in the alveoli and the arteries. ideally there should be no difference

A-a gradient = PAO2 - PaO2