First Aid-Physiology

Question 1

What happens when Alveolar partial pressure of oxygen falls?

Answer 1

Hypoxic vasoconstriction which diverts blood to other well ventilated areas for better gas exchange

Question 2

How can COPD lead to cor pulmonale?

Answer 2

COPD causes hypoxic vasoconstriction which leads to pulmonary hypertension and eventual cor pulmonale as the the right ventricle dilates because it is pumping against greater pressures

Question 3

Alveolar gas equation

Answer 3

PAlveolar= PIO2 (150mmHg) - Parterial CO2/ R

Question 4

A-a gradient

Answer 4

The amount of oxygen that can be transferred from alveolar spaces to arterial spaces….the lower the difference the better the transfer (better diffusion)
normal is 10-15 mmHg

Question 5

Widened A-a gradient causes of hypoxemia?

Answer 5

means that oxygen is getting into the lungs but is not being transferred to the blood

1. V/Q mismatch
2. Right to Left Shunting
3. diffusion limitation (fibrosis)

Question 6

What is Hypoxemia? Hypoxia?

Answer 6

1. Hypoxemia–is decreased partial pressure of oxygen in the blood
2. Hypoxia– is decreased delivery of oxygen to the tissues

Question 7

Normal A-a gradient of hypoxemia?

Answer 7

means that the oxygen is not getting in. But transfer from alveoli to blood is still efficient

1. high altitudes
2. HypOventilation