Respiratory Physiology I

Question 1

5 major processes involved in respiration

Answer 1

1. Ventilation
2. Gas exchange
3. Transport of O2 and CO2 in the circulatory system
4. Diffusion of gases between capillaries and the cells of organ systems
5. Control of respiration by receptors, chemoreceptors, and the CNS

Question 2

Ventilation

Answer 2

Movement of air into and out of the lungs

Question 3

Gas exchange

Answer 3

Diffusion of gases at the alveolar-capillary membrane in the pulmonary circulation

Question 4

Respiratory cycle

Answer 4

Inhalation followed by exhalation

Question 5

Inhalation

Answer 5

muscular contraction expands the thorax and pulls air into the lungs

Question 6

Exhalation

Answer 6

Elastic forces that are stored in the stretched lungs and thoracic rib cage allow the thorax to decrease in size, and air can leave the lungs

Question 7

Examples of conducting airways

Answer 7

Nasal cavity
Hard palate
Soft palate
Esophagus
Trachea
Larynx
Epiglottis
Tonsil
Tongue

Question 8

7 characteristics of conducting airways

Answer 8

1. Pathway for ventilation
2. Larger airways: mouth to bronchioles
3. No gas exchange
4. Anatomic dead-space
5. Distribution of air
6. Warm/humidify air
7. Remove inhaled particles

Question 9

Examples of respiratory airways

Answer 9

Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli

Question 10

5 characteristics of respiratory airways

Answer 10

1. Pathway for gas exchange
2. Smaller airways: respiratory bronchioles to alveoli
3. Significant gas exchange
4. Alveolar dead-space
5. O2/CO2 gas exchange

Question 11

Sympathetic effect on airways

Answer 11

Norepinephrine released, causes dilation

Question 12

Parasympathetic effect on airways

Answer 12

muscarinic cholinergic receptors activated, causes constriction

Question 13

Inflammatory mediator effect on airways

Answer 13

Histamines cause narrowing of smooth muscle, i.e. constriction

Question 14

Inhaled irritant effect on airways

Answer 14

Irritants stimulate tracheo-bronchial irritant receptors, cause constriction

Question 15

Anatomic dead space

Answer 15

The volume in the conducting airways that does not participate in gas exchange

Question 16

Alveolar dead space

Answer 16

Alveoli that are ventilated by poorly perfused

Question 17

Physiologic dead space

Answer 17

Anatomic dead space + Alveolar dead space

i.e. the total volume of the lungs that does not participate in gas exchange

Question 18

Shunt

Answer 18

Perfusion without ventilation

Question 19

Minute ventilation

Answer 19

The total volume of air breathed per minute

Question 20

Tidal volume

Answer 20

The volume of air in each breath

Question 21

Respiratory rate

Answer 21

The number of breaths per minute

Question 22

Minute ventilation equation

Answer 22

minute ventilation = tidal volume - respiratory rate

Question 23

3 things that increase minute ventilation

Answer 23

1. Exercise
2. Metabolic rate
3. Sympathetic activation

Question 24

What is best for detecting alveolar ventilation?

Answer 24

Arterial PCO2 because there are too many factors that can affect alveolar PO2

Question 25

Inspiratory reserve volume

Answer 25

the additional volume of air that can be breathed in over and above tidal volume

Question 26

Expiratory volume

Answer 26

The additional volume of air that can be breathed out below tidal volume

Question 27

Residual volume

Answer 27

The volume of air remaining in the lungs after a forced maximal aspiration

Question 28

Inspiratory capacity

Answer 28

The tidal volume plus the inspiratory reserve volume

Question 29

Functional residual capacity

Answer 29

Expiratory reserve volume + Residual volume

i.e. volume of air remaining in lungs after expiration of normal breath

Question 30

Vital capacity

Answer 30

Inspiratory capacity + expiratory reserve volume

Question 31

Total lung capacity

Answer 31

Sum of all lung volumes