RESP GX

Question 1

partial pressure of nitrogen in the atmosphere is?

Answer 1

600 mmHg

Question 2

partial pressure of oxygen in the atmosphere is?

Answer 2

160 mmHg

Question 3

what are the four important partial pressures to consider?

Answer 3

PO2, PCO2, PH2O, and PN2

Question 4

PH2O and PN2 are what in the atmosphere?

Answer 4

zero

Question 5

what is the inhaled partial pressure of oxygen and nitrogen?

Answer 5

O2 is 150 mmHg

N2 is 563 mmHg

Question 6

typical functional residual capacity?

Answer 6

2.3 L

Question 7

how many ml of the 500 ml we inhale make it to the alveoli?

Answer 7

350 mL

Question 8

each breath replace how much of the gas in the lungs?

Answer 8

15%, see below

350/2300

Question 9

normal alveolar respiration at rest is how much? how much in mL of O2 and CO2 leave the blood?

Answer 9

4.2 L/min

250 mL of O2 enter blood and 200 mL of CO2 leave the blood

Question 10

during exercise, alveolar ventilation rises to how much? (hint in L/min)

Answer 10

17 L/min

partial pressures of the gases stay the same no what the activity

Question 11

T/F, CO2 has much higher solubility coefficient than oxygen?

Answer 11

T, more soluble than most gases

imp because this determines how much gas can be found in the plasma

Question 12

what are the factors that affect diffusion besides partial pressure?

Answer 12

cross sectional
solubility coefficient
distance
molecular weight

Question 13

what are the partial pressures of oxygen, CO2, nitrogen?

Answer 13

1. 0
2. 3
3. 53

Question 14

how many alveoli in the two lungs?

Answer 14

300 million

Question 15

total area of diffusion across the rest units is how much in adults?

Answer 15

50-100 m^2

Question 16

total amount of blood in the lungs?

Answer 16

60-140 mLs

Question 17

this can be a limiting factor if increased in diseased states?

Answer 17

diffusional distance

Question 18

in emphysema what is the limiting factor?

Answer 18

total surface area becomes decreased

Question 19

what is diffusing capacity?

Answer 19

ability of gas to diffuse from alveoli to blood

Question 20

what is important to note about diffusing capacity?

Answer 20

its the volume of gas that diffuses through the membrane each minute due to 1 mmHg pressure difference

Question 21

what is the pressure gradient for oxygen at rest? mean alveolar oxygen pressure? mean capillary oxygen pressure? this meant how much oxygen can diffuse into the blood?

Answer 21

11 mmHg

104 mmHg

93 mmHg

231 ml/min from pressure gradient (11 mmHg) x diffusing capacity (21 mL/min/mmHg)

Question 22

so during exercise, diffusing capacity for oxygen rises to 65 mL/min/mmHg which equates to 715 mL/min O2 delivered to blood during exercise, what is this increase due to?

Answer 22

opening of previously closed pulmonary capillaries to handle increased CO

better matching of ventilation to perfusion at all alveoli

note that CO2 diffusing capacity increases too