Gas Transport & Regulation of Ventilation

Question 1

Solubility of Gases

Answer 1

partial pressures are able to equalize but concentrations cannot

• Carbon dioxide is more soluble in plasma than Oxygen

Question 2

Cooperative Binding of Hemoglobin

Answer 2

hemoglobins 4 binding sites for oxygen increase in affinity when one Oxygen binds

Question 3

Oxygen content of plasma

Answer 3

3mL/L of blood
- occurs when there is only diffusion

Question 4

Oxygen content of RBC’s

Answer 4

197mL/L of blood
- occurs when there is hemoglobin binding

Question 5

Oxygen Partial Pressure of resting cell

Answer 5

40mm hg

Question 6

Oxygen Partial Pressure in Alveoli

Answer 6

100mm hg

Question 7

P50

Answer 7

The partial pressure needed for hemoglobin to be 50% saturated
- increased P50 means that hemoglobin affinity has decreased
- decreased P50 means that hemoglobin affinity has decreased

Question 8

pH affect on Hemoglobin binding

Answer 8

• increased pH (basic) decreases the P50, which increases hermoglobin affinity
• decreased pH (acidic) increases the P50, which decreases hemoglobin affinity

Question 9

Partial Pressure of CO2 affect on Hemoglobin binding

Answer 9

• increased Pco2 increases P50, which decreases hemoglobin affinity
• decreased Pco2, decreases P50, which increases hemoglobin affinity

Question 10

O2 transport in blood

Answer 10

2% dissolves in plasma
98% travels with hemoglobin

Question 11

Carbon Dioxide transport in blood

Answer 11

7% transported in plasma
23% transported binded to hemoglobin but not on the prophyrin ring
70% transported as bicarbonate dissolved in plasma (HCO3)

Question 12

Central chemoreceptors function (medulla)

Answer 12

increase activity with elevated partial pressure of carbon dioxide
- causes increased rate and depth of respiration

Question 13

Peripheral chemoreceptors function (carotid sinuses/aortic arch)

Answer 13

• increase activity with elevated partial pressure of carbon dioxide and H+
• increased activity with decreased partial pressure of Oxygen
• results in an increased rate and depth of respiration