Respiratory Physiology IV

Question 1

Forms of gas in circulation

Answer 1

Dissolved gas
Bound gas
Chemically modified gas

Question 2

O2 is carried in blood in which two forms?

Answer 2

Dissolved form and bound form

Question 3

Oxyhemoglobin

Answer 3

O2 bound

Question 4

Deoxyhemoglobin

Answer 4

O2 not bound

Question 5

Methemoglobin

Answer 5

Fe3+ heme, will not bind/transport O2

Question 6

Hemoglobin S

Answer 6

• Variant of Hb that causes sickle cell disease

- Amino acid substitution (glutamate to valine)

Question 7

Definition of oxygen binding capacity

Answer 7

Maximum amount of O2 bound to Hb

Question 8

Definition of oxygen content

Answer 8

02-binding capacity x % saturation

Question 9

Definition of oxygen delivery

Answer 9

Cardiac output x O2 content of blood

Question 10

O2 saturation curve

Answer 10

• % saturation of Hb is a function of the PO2 in the blood

- Cooperativity in binding of O2

Question 11

Right shift of O2 saturation curve results in what?

Answer 11

More unloading of O2 to tissues

Question 12

Left shift of O2 saturation curve results in what?

Answer 12

Hb has higher affinity for O2, so less unloading to tissues

Question 13

What causes O2 saturation curve shift to right?

Answer 13

Decreased pH and increased CO2
Increased body temperature
Increased 2,3-DPG

Question 14

What causes O2 saturation curve shift to left?

Answer 14

Increased pH and decreased CO2
Decreased body temperature
Decreased 2,3-DPG
Carbon monoxide poisoning
Hb F

Question 15

Forms of CO2 in circulation

Answer 15

Dissolved gas
Bound gas (to Hb)
Chemically modified gas (carried as HCO3-)

Question 16

Long term regulation of blood pH

Answer 16

Kidneys can alter secretion rate of hydrogen ions and re-absorption rate of bicarbonate to control blood pH

Question 17

Short term regulation of blood pH

Answer 17

Variations in alveolar ventilation can be used to correct pH

Question 18

Metabolic acidosis

Answer 18

Decrease in HCO3- leads to decrease in pH (diarrhea)

Question 19

Metabolic alkalosis

Answer 19

Increase in HCO3- leads to increase in pH (vomiting)

Question 20

Respiratory acidosis

Answer 20

Hypoventilation resulting in CO2 retention and decreased pH

Question 21

Respiratory alkalosis

Answer 21

Hyperventilation resulting in CO2 loss and increased pH