Chapter 23

Question 1

The mechanism behind breathing involves

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-using the intercostal muscles to push air into the lungs.
-changing the volume of the thoracic cavity to change the pressure.
-filling the diaphragm with air.
-changing the pressure in the thoracic cavity to change the volume.

Answer 1

changing the volume of the thoracic cavity to change the pressure.

Question 2

All of the following are required to breathe in EXCEPT

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contraction of the diaphragm.

contraction of the lungs.

increasing the volume of the thoracic cavity.

contraction of the intercostal muscles.

Answer 2

contraction of the lungs.

Question 3

When the volume of the thoracic cavity increases, the lungs expand, and air enters. What stops this process?

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The ribs descend.

The intercostal muscles contract.

The pressure of the air inside the lungs and outside the body reach equilibrium.

The diaphragm relaxes.

Answer 3

The pressure of the air inside the lungs and outside the body reach equilibrium.

Question 4

The process of breathing.

Answer 4

respiration

Question 5

The process of smelling.

Answer 5

olfaction

Question 6

The organ system that controls breathing; composed of the lungs and the air passageways.

Answer 6

respiratory system

Question 7

The hollow cavities in bone or other tissue.

Answer 7

sinuses

Question 8

A muscular passage in the throat between the mouth and the esophagus.

Answer 8

pharynx

Question 9

The organ that houses the vocal cords.

Answer 9

larynx

Question 10

The air tube that leads from the larynx to the bronchi.

Answer 10

trachea

Question 11

The branch-like structure of tubes that carries air from the trachea to the lungs.

Answer 11

bronchial tree

Question 12

The air sacks of the lungs

Answer 12

alveoli

Question 13

The process of breathing in.

Answer 13

inspiration

Question 14

The partition that separates thoracic and abdominal cavities.

Answer 14

diaphragm

Question 15

The space between the ribs.

Answer 15

intercostals

Question 16

The nasal cavity
has openings for the paranasal sinuses.
has a vestibule, which contains the olfactory epithelium.
is connected to the pharynx by the nares.
has passageways called conchae.
is lined with squamous epithelium, except for the vestibule.

Answer 16

has openings for the paranasal sinuses.

Question 17

The larynx
connects the oropharynx to the trachea.
has three single and six paired cartilages.
contains the vocal folds.
contains the vestibular folds.
All of these are correct.

Answer 17

All of these are correct

Question 18

Terminal bronchioles branch to form
the alveolar duct.
alveoli.
bronchioles.
respiratory bronchioles.

Answer 18

respiratory bronchioles.

Question 19

During an asthma attack, a person has difficulty breathing because of constriction of the
trachea.
bronchi.
terminal bronchioles.
alveoli.
respiratory membrane.

Answer 19

terminal bronchioles.

Question 20

During quiet expiration, the
abdominal muscles relax.
diaphragm moves inferiorly.
external intercostal muscles contract.
thorax and lungs passively recoil.
All of these are correct.

Answer 20

thorax and lungs passively recoil.

Question 21

The parietal pleura

covers the surface of the lung.
covers the inner surface of the thoracic cavity.
is the connective tissue partition that divides the thoracic cavity into right and left pleural cavities.
covers the inner surface of the alveoli.
is the membrane across which gas exchange occurs.

Answer 21

covers the inner surface of the thoracic cavity.

Question 22

Contraction of the bronchiolar smooth muscle has which of these effects?
A smaller pressure gradient is required to get the same rate of airflow, compared with normal bronchioles.
It increases airflow through the bronchioles.
It increases resistance to airflow.
It increases alveolar ventilation.

Answer 22

It increases resistance to airflow.

Question 23

During expiration, the intra-alveolar pressure is
lower than the pleural pressure.
greater than the atmospheric pressure.
lower than the atmospheric pressure.
unchanged.

Answer 23

greater than the atmospheric pressure.

Question 24

Normally, which of the following keeps the lungs from collapsing?
surfactant
pleural pressure
elastic recoil
Both a and b are correct.

Answer 24

Both a and b are correct.

Question 25

Immediately after the creation of an opening through the thorax into the pleural cavity air flows through the hole and into the pleural cavity. air flows through the hole and out of the pleural cavity. air flows neither out nor in. the lung protrudes through the hole.

Answer 25

air flows through the hole and into the pleural cavity.

Question 26

Compliance of the lungs and thorax is the volume by which the lungs and thorax change for each unit change of intra-alveolar pressure. increases in emphysema. decreases because of lack of surfactant. All of these are correct.

Answer 26

All of these are correct.

Question 27

Given these lung volumes: (1) tidal volume = 500 mL (2) residual volume = 1000 mL (3) inspiratory reserve volume = 2500 mL (4) expiratory reserve volume = 1000 mL (5) dead space = 1000 mL The vital capacity is 3000 mL. 3500 mL. 4000 mL. 5000 mL. 6000 mL.

Answer 27

4000 mL.

Question 28

Alveolar ventilation is the tidal volume times the respiratory rate. minute volume plus the dead space. amount of air available for gas exchange in the lungs. vital capacity divided by the respiratory rate. inspiratory reserve volume times minute volume.

Answer 28

amount of air available for gas exchange in the lungs.

Question 29

The rate of diffusion of a gas across the respiratory membrane increases as the respiratory membrane becomes thicker. surface area of the respiratory membrane decreases. partial pressure gradient of the gas across the respiratory membrane increases. diffusion coefficient of the gas decreases. All of these are correct.

Answer 29

partial pressure gradient of the gas across the respiratory membrane increases.

Question 30

Oxygen is mostly transported in the blood dissolved in plasma. bound to blood proteins. within HCO3−. bound to the heme portion of hemoglobin.

Answer 30

bound to the heme portion of hemoglobin.

Question 31

Carbon dioxide is mostly transported in the blood dissolved in plasma. bound to blood proteins. within HCO3−. bound to the heme portion of hemoglobin. bound to the globin portion of hemoglobin.

Answer 31

within HCO3−.

Question 32

The chloride shift promotes the transport of CO2 in the blood. occurs when Cl− replaces HCO3− within red blood cells. maintains electrical neutrality in red blood cells and the plasma. All of these are correct. Answer

Answer 32

occurs when Cl− replaces HCO3− within red blood cells.

Question 33

The oxygen-hemoglobin dissociation curve is adaptive because it shifts to the right in the pulmonary capillaries and to the left in the tissue capillaries. shifts to the left in the pulmonary capillaries and to the right in the tissue capillaries. does not shift.

Answer 33

shifts to the left in the pulmonary capillaries and to the right in the tissue capillaries.

Question 34

Which of these parts of the brainstem is correctly matched with its main function? ventral respiratory groups—stimulate the diaphragm dorsal respiratory groups—limit inflation of the lungs pontine respiratory group—is involved in the switch between inspiration and expiration All of these are correct.

Answer 34

pontine respiratory group—is involved in the switch between inspiration and expiration

Question 35

The chemosensitive area stimulates the respiratory center when blood CO2 levels increase. stimulates the respiratory center when blood pH increases. is located in the pons. stimulates the respiratory center when blood O2 levels increase. All of these are correct.

Answer 35

is located in the pons.

Question 36

Blood O2 levels are more important than CO2 levels in the regulation of pulmonary ventilation. need to change only slightly to cause a change in pulmonary ventilation. are detected by sensory receptors in the carotid and aortic bodies. All of these are correct.

Answer 36

are detected by sensory receptors in the carotid and aortic bodies.