Topic 13: Respiratory System - Clinical Applications

Question 1

What occurs in hyperventilation? (4)

Answer 1

1) decreased arterial PCO2
2) causes cerebral vasoconstriction (intrinsic metabolic response)
3) decreases PO2 to the brain
4) causes dizziness

Question 2

What occurs in hypoventilation? (2)

Answer 2

• increase arterial PCO2
• increase H+, leading to acidosis

Question 3

What is CO caused by?

Answer 3

• incomplete burning of gas (cars, furnaces, etc)

Question 4

How does CO poisoning occur? (4)

Answer 4

1) CO binds 210x more strongly to iron than O2, forming carboxyHb (HbCO)
2) results in decreased TOTAL O2
3) no change in PO2 or PCO2 (dissolved gases)
4) therefore ventilation rate does not change