Unit 5 - A & P Module - Exchange and delivery of O2 and CO2

Question 1

Approximately 79% of the total atmospheric pressure is taken up by nitrogen. At the top of Mount Everest, Patm = 250 mmHg. The partial pressure of nitrogen there is __________.

Answer 1

197.5 mmHg

Question 2

If bronchioles are constricted, __________.

Answer 2

Pᴏ₂ in the pulmonary capillaries will decrease and Vᴀ/Q will decrease

Question 3

All of the following statements related to “the bends” are true.

Answer 3

Increased water pressure due to increased depth causes more gases such as nitrogen to be dissolved in the blood; ascending too quickly causes nitrogen gas to come out of solution in body fluids, creating bubbles; and nitrogen gas bubbles can clog blood vessels and lodge in joints and the nervous system.

Question 4

On average, the number of oxygen molecules bound to heme groups in hemoglobin in venous blood is __________.

Answer 4

three

Question 5

One effect of carbon monoxide is to __________.

Answer 5

decrease the affinity of hemoglobin for oxygen

Question 6

The respiratory quotient is defined as __________.

Answer 6

the ratio of the amount of carbon dioxide produced by the body to the amount of oxygen consumed

Question 7

In the chloride shift, chloride ions are exchanged for __________ across the erythrocyte membrane.

Answer 7

HCO3-

Question 8

Conditions that would shift the hemoglobin-oxygen dissociation curve to the right include decreases in __________.

Answer 8

pH

Question 9

All of the following statements are true.

Answer 9

Oxygen binding to hemoglobin shows positive affinity, and the fewer oxygen molecules bound to hemoglobin, the lower the affinity of hemoglobin for oxygen.

Question 10

Each of the following can result in a decreased PO2 in arterial blood.

Answer 10

Pulmonary edema,
Emphysema,
Fibrotic lung disease

Question 11

The respiratory receptors of the brain receive input from __________

Answer 11

peripheral chemoreceptors,
irritant receptors,
pulmonary stretch receptors,
central chemoreceptors

Question 12

Central chemoreceptors are stimulated by __________.

Answer 12

H+ ions produced in cerebrospinal fluid from CO2 that crosses the blood-brain barrier

Question 13

The following has a greater concentration (partial pressure) in exhaled air than in inhaled air.

Answer 13

CO2 and H2O vapor

Question 14

PO2 decreases and PCO2 increases in the pulmonary alveoli due to __________.

Answer 14

inhaled air mixing with air in the dead air space, the increased partial pressure of water vapor, rapid diffusion of gases across the respiratory membranes

Question 15

Hemoglobin has a decreased affinity for oxygen at the tissues due to the __________.

Answer 15

Bohr shift and carbaminohemo effect

Question 16

Ventilation-perfusion ratios that are not equal to 1 can be the result of __________.

Answer 16

gravity, airway obstruction, damage to pulmonary capillaries, and emphysema

Question 17

For oxygen gas in air and dissolved in water, at equilibrium, __________.

Answer 17

the partial pressure of oxygen in air is equal to the partial pressure of oxygen in water

Question 18

The following statements are about exercise and respiration

Answer 18

Feedforward mechanisms help to increase ventilation in preparation for exercise, minute ventilation is controlled by both humoral and neurogenic mechanisms, negative feedback mechanisms help prevent hyperventilation.

Question 19

If carbonic anhydrase activity decreased, the following would increase in the plasma.

Answer 19

pH, PCO2, and chloride ions