lecture 18 - o2 and co2 exchange

Question 1

what is the respiratory minute volume

Answer 1

tidal volume (L/breath) x respiratory rate (breaths per minute) = respiratory minute volume (L/minute)

Question 2

what is the dead space in the lungs

Answer 2

the air that we inhale that never reaches the alveoli, so therefore can not gas exchange

Question 3

what is the alveolar ventilation

Answer 3

tidal volume (L/breath) - dead space (L/breath) x respiratory rate (breaths/minute) = alveolar ventilation (L/minute)

Question 4

what is partial pressure

Answer 4

the individual pressure that each gas exerts in a gas mixture

Question 5

what does D stand for in ficks law of diffusion and what does it depend on

Answer 5

diffusion constant and depends on gas solubility + its molecular weight

Question 6

what does A stand for in ficks law of diffusion

Answer 6

surface area

Question 7

what does T stand for in ficks law of diffusion

Answer 7

thickness
- the distance between the alveolar air and the blood is very small = allows for efficient gas exchange

Question 8

what does p1-p2 stand for in ficks law of diffusion

Answer 8

the pressure difference
- pressure drives diffusion

Question 9

what does the alveolar partial pressure of O2 depend on

Answer 9

1. partial pressure of oxygen in inspired air
2. alveolar ventilation
3. oxygen composition - blood oxygen

Question 10

what happens to oxygen consumption and oxygen levels in venous blood at low activity levels

Answer 10

reduced oxygen consumption and higher levels of oxygen in venous blood

Question 11

what happens to oxygen consumption and oxygen levels in venous blood at high activity levels

Answer 11

increased oxygen consumption and lower levels of oxygen in venous blood

Question 12

what does alveolar partial pressure of CO2 depend on

Answer 12

1. partial pressure of CO2 in inspired air
2. alveolar ventilation
3. carbon dioxide production