BIO 360 - Exam 4 - Chapter 17 Review Questions

Question 1

List four functions of the respiratory system.

Answer 1

gas exchange, vocalization, pH regulation, and protection

Question 2

Give two definitions for the word respiration.

Answer 2

Cellular respiration—oxygen and nutrients are used for energy production.
External respiration—gas exchange between atmosphere and cells.

Question 3

Which sets of muscles are used for normal quiet inspiration? For normal, quiet expiration? For active expiration? What kind(s) of muscles are the different respiratory muscles (skeletal, cardiac, or smooth)?

Answer 3

Quiet inspiration—external intercostals, scalenes, and diaphragm.

Quiet expiration—no significant muscle contraction.

Active expiration—internal intercostals and abdominal muscles. These are all skeletal muscles.

Question 4

Give two functions of pleural fluid.

Answer 4

Pleural fluid reduces friction and holds the lungs tight against the chest wall.

Question 5

Name the anatomical structures that an oxygen molecule passes on its way from the atmosphere to the blood.

Answer 5

Nose and mouth, pharynx, larynx, trachea, main bronchus, secondary bronchi, bronchioles, epithelium of the alveoli, interstitial fluid, and capillary endothelium

Question 6

Diagram the structure of an alveolus, and state the function of each part. How are capillaries associated with an alveolus?

Answer 6

Fig.17.2g and h. Type I—gas exchange; type II—surfactant. Macrophages ingest foreign material.
Capillary endothelium is almost fused to the alveolar epithelium, and the space between alveoli is almost filled with capillaries.

Question 7

Trace the path of the pulmonary circulation. About how much blood is found here at any given moment? What is a typical arterial blood pressure for the pulmonary circuit, and how does this pressure compare with that of the systemic circulation?

Answer 7

Right ventricle to pulmonary trunk, to left and right pulmonary arteries, smaller arteries, arterioles, capillaries, venules, small veins, pulmonary veins, left atrium.

Contains about 0.5 L of blood.
Arterial pressure is 25/8, compared with 120/80 for systemic.

Question 8

What happens to inspired air as it is conditioned during its passage through the airways?

Answer 8

Warmed, humidified, and cleaned (filtered)

Question 9

During inspiration, most of the thoracic volume change is the result of movement of the .

Answer 9

diaphragm

Question 10

Describe the changes in alveolar and intrapleural pressure during one respiratory cycle.

Answer 10

See Fig. 17.9.

Question 11

Of the three factors that contribute to the resistance of air flow through a tube, which plays the largest role in changing resistance in the human respiratory system?

Answer 11

radius of the airways

Question 12

Match the following items with their correct effect on the bronchioles:

(a) histamine
(b) epinephrine
(c) acetylcholine
(d) increased PCO2

(1) bronchoconstriction
(2) bronchodilation
(3) no effect

Answer 12

(a) 1, (b) 2, (c) 1, (d) 2

Question 13

What is the function of surfactants in general? In the respiratory system?

Answer 13

Surfactant decreases surface tension of water and makes it easier for lungs to inflate and stay inflated.

Question 14

If a person increases her tidal volume, what would happen to her alveolar PO2?

Answer 14

Increased tidal volume increases alveolar PO2.

Question 15

Compare and contrast the terms in each of the following sets:
(a) compliance and elastance
(b) inspiration, expiration, and ventilation
(c) intrapleural pressure and alveolar pressure
(d) total pulmonary ventilation and alveolar ventilation
(e) type I and type II alveolar cells
(f) pulmonary circulation and systemic circulation

Answer 15

(a) Compliance—ability to deform in response to force; elastance—ability to resume original shape after deforming force has been removed.
(b) Ventilation—air exchange between atmosphere and lungs. Inspiration—air movement into lungs. Expiration—air movement out of lungs.
(c) Intrapleural pressure—always subatmospheric (except during forced expiration, when it may become positive); alveolar pressures vary from subatmospheric to above atmospheric.
(d) Total pulmonary ventilation—volume of air entering or leaving airways in a given period of time. Alveolar ventilation—volume of air entering or leaving alveoli in a given period of time.
(e) Type I—thin cells for gas exchange; Type II—synthesize and secrete surfactant.
(f) Pulmonary—from right heart to lung and back to left atrium. Systemic—left heart to most tissues and back to right atrium.

Question 16

List the major paracrines and neurotransmitters that cause bronchoconstriction and bronchodilation. What receptors do theyact through? (muscarinic, nicotinic, a, B1, B2)

Answer 16

Bronchoconstrictors: histamine, leukotrienes, acetylcholine (muscarinic)

Bronchodilators: carbon dioxide, epinephrine (β2)

Question 17

Compile the following terms into a map of ventilation. Use up arrows, down arrows, greater than symbols
and less than symbols
as modifiers. You may add other terms.

abdominal muscles
air flow
contract
diaphragm
expiratory muscles
external intercostals
forced breathing
in, out, from, to

inspiratory muscles
internal intercostals
PA
Patm
Pintrapleural
quiet breathing
relax
scalenes

Answer 17

See Figs. 17.8 and 17.9.

Question 18

Decide whether each of the following parameters will increase, decrease, or not change in the situations given.

(a) airway resistance with bronchodilation
(b) intrapleural pressure during inspiration
(c) air flow with bronchoconstriction
(d) bronchiolar diameter with increased
(e) tidal volume with decreased compliance
(f) alveolar pressure during expiration

Answer 18

(a) decrease, (b) decrease, (c) decrease, (d) increase, (e) decrease, (f) increase

Question 19

Define the following terms: pneumothorax, spirometer, auscultation, hypoventilation, bronchoconstriction, minute volume, partial pressure of a gas.

Answer 19

Pneumothorax—air in the pleural cavity. Spirometer—device used to measure ventilation. Auscultation—listening for body sounds. Hypoventilation—decreased pulmonary ventilation. Bronchoconstriction—decrease in bronchiole radius. Minute volume—total pulmonary ventilation. Partial pressure of gas—portion of total pressure in a mixture of gases that is contributed by a specific gas.

Question 20

Match the descriptions to the appropriate phase(s) of ventilation:

(a) usually depend(s) on elastic recoil.
(b) is/are easier when lung compliance decreases.
(c) is/are driven mainly by positive intrapleural pressure generated by muscular contraction.
(d) is usually an active process requiring smooth muscle contraction.

(1) inspiration
(2) expiration
(3) both inspiration and expiration
(4) neither

Answer 20

(a) 2, (b) 2, (c) 4, (d) 4

Question 21

Will pulmonary surfactant increase, decrease, or not change the following?

(a) work required for breathing
(b) lung compliance
(c) surface tension in the alveoli

Answer 21

(a) decrease, (b) increase, (c) decrease