respiratory 3

Question 1

O2 and CO2 gas exchange occurs solely by

Answer 1

diffusion

Question 2

henry’s law

Answer 2

when a mixture of gases is in contact wth a liquid, each gas will dissolve in the liquid in proportion to its partial pressure
at equlibrium - partial pressures in alveoli and capillaries will be equal

Question 3

diffusion rate depends on

Answer 3

• surface area
• concentration (P) gradient
• thickness of the membrane
• diffusion constant (solubility, molecular weight)

Question 4

exercise decreases

Answer 4

time available for diffusion

Question 5

limitations to pulmonary gas exchange

Answer 5

1. low inspired oxygen
2. hypoventilation
3. diffusion limitations
4. ventilation-perfusion mismatching

Question 6

ventilation perfusion coupling

Answer 6

lungs and blood flow to the lungs trying to match each other
V/Q ration

Question 7

VENTILATION

Answer 7

THE AIR REACHING THE ALVEOLI

Question 8

perfusion

Answer 8

the blood reaching the alveoli

Question 9

impaired ventilation

Answer 9

shunt

Question 10

impaired perfusion

Answer 10

dead space

Question 11

when theres not enough ventilation

Answer 11

the bronchioles dilate and the pulmonary arterioles constrict

Question 12

when theres not enough perfusion

Answer 12

the pulmonary arterioles dilate and the bronchioles constrict

Question 13

shunts

Answer 13

venous blood going through the lungs without being oxygenated
0 ventilation perfusion ratio

Question 14

dead space

Answer 14

ventilated alveoli don’t receive blood

infinite ventilation perfusion ratio

Question 15

regional differences in perfusion pressure

Answer 15

perfusion pressure is greater lower down in the lungs

bottom is over perfused and the top is under perfused

Question 16

if you have a cancer at the bottom of your lungs

Answer 16

you’ll be under perfused overall because the bottom is over perfused

Question 17

high V/Q

Answer 17

usually pulmonary embolism

Question 18

low V/Q

Answer 18

chronic bronchitis, asthma, pulmonary oedema

Question 19

blood pO2

Answer 19

100mmHg at lungs and 40mmHg after circulating

Question 20

carbamino

Answer 20

CO2 combines with terminal amino groups of proteins (haemoglobin)
CO2 and O2 bind seperate parts of haemoglobin

Question 21

bicarbonate

Answer 21

most CO2 in blood is carried as bicarbonate

Question 22

3 ways CO2 is transported

Answer 22

• dissolved in blood
• carbamino
• bicarbonate

Question 23

most CO2 is transported as

Answer 23

bicarbonate

Question 24

carbonic anhydrase

Answer 24

converts carbon dioxide to bicarbonate

Question 25

what type of carbon dioxide gets exchanged the most

Answer 25

carbamino

Question 26

Bohr effect

Answer 26

CO2 loading causes O2 offloading

Question 27

Haldane effect

Answer 27

O2 loading causes CO2 off loading