EXAM 3 QUESTIONS

Question 1

Apart from facilitating the supply of oxygen for aerobic metabolism and the removal of the waste product carbon dioxide, what else does the respiratory system do?

Answer 1

Answer: additionally helps move air into the nose for olfaction and through the structures used for vocalization. Can exhale some volatile drugs and metabolites; can be utilized to administer certain drugs.

Question 2

What process drives gas exchange in the lungs?

Answer 2

diffusion; from high to low pressure (= concentration gradient).

Question 3

What is partial pressure? If our atmosphere is ~20% oxygen, what is the partial pressure of oxygen?

Answer 3

the individual contributions to the overall gas pressure by the different gases in a mixture; if O2 is ~20% of our atmosphere then the partial pressure of O2 (= concentration) is 20% of atmospheric pressure (760mmHg).

Question 4

What process transports gases in the circulation between the lungs and tissues?

Answer 4

bulk transport due to blood being circulated.

Question 5

Ignoring the fact that inhaled air always mixes with some “old” air in the alveoli, why is the partial pressure of oxygen in the alveoli reduced as compared to the atmosphere surrounding us?

Answer 5

SWVP; at 37oC it is 47mmHg.

Question 6

What is the major cleaning mechanism evident throughout all but the smallest airways/bronchioles?

Answer 6

cilia moving watery mucus (“fly paper”) out of the lungs.

Question 7

Movement in and out of the lungs is by?

Answer 7

bulk flow due to pressure difference

Question 8

What keeps all but the smallest airways open?

Answer 8

cartilage rings or plates.

Question 9

What “law” describes the movement of air in and out of the lungs?

Answer 9

Boyle’s Law; P1V1 = P2V2 at constant T.

Question 10

Blood flow through the lungs must equal cardiac output; True or false?

Answer 10

True.

Question 11

Why do you get “zones” of blood flow in the lungs?

Answer 11

due to gravity (so no effect lying down).

Question 12

Normally what “zones” do you see?

Answer 12

Zone 2 (intermittent flow only around systolic peak pressure in pulmonary circulation) and Zone 3 (constant as Blood flow/pressure always adequate).

Question 13

What effect is INCREASE CO/exercise have on the “zones?”

Answer 13

all becomes Zone 3.

Question 14

What causes constriction of the pulmonary arterioles/capillaries?

Answer 14

OXYGEN! Opposite to normal but means you don’t perfuse alveoli which are not ventilated (matching: more later!).

Question 15

Pulmonary capillary pressure is typically greater than that of systemic/peripheral capillaries; True or false?

Answer 15

False.

Question 16

To compensate for chronically elevated pulmonary capillary pressures the lymphatic system can increase its rate of drainage by?

Answer 16

x10.

Question 17

The air inhaled during normal/gentle/tidal breathing exchanges with what lung “volume?”

Answer 17

Functional Residual Capacity (FRC).

Question 18

The air inhaled during maximal breathing exchanges with what lung “volume?”

Answer 18

Residual Volume (RV).

Question 19

 O2 and CO2 diffuse through cell membranes faster than water; True or false?

Answer 19

True.