Deck 54: Control of Breathing

Question 1

The calcium hydroxide experiment demonstrates that

A) there is a much lower concentration of O₂ in expired air than in atmospheric air.
B) there is a much higher concentration of CO₂ in expired air than in atmospheric air.
C) there is a much higher concentration of O₂ in expired air than in atmospheric air.
D) there is a much lower concentration of CO₂ in expired air than in atmospheric air.
E) the concentrations of CO₂ in expired air and atmospheric air are approximately equal.

Answer 1

B

Question 2

Which of the following is not detected by the peripheral chemoreceptors?

A) An increase in the level of carbon dioxide in the blood
B) A decrease in the level of oxygen in the blood
C) An increase in the level of hydrogen ions in the blood
D) An increase in the level of sodium ions in the blood
E) The peripheral chemoreceptors detect all of these changes.

Answer 2

D

Question 3

Muscles of inspiration include all of the following except the

A) external obliques.
B) pectoralis minor.
C) scalenes.
D) external intercostals.
E) All of these are muscles of inspiration.

Answer 3

A

Question 4

The ventral respiratory group sends impulses through an integrating center in the spinal cord, and then to the intercostal nerves, which stimulate contraction of the diaphragm.

Question 5

Which of the following substances binds to hydrogen ions, to alleviate respiratory acidosis?

A) Bicarbonate ions
B) Carbonic acid
C) Sodium bicarbonate
D) Water
E) Carbon dioxide

Question 6

Which major region of the central nervous system contains the respiratory centers?

A) spinal cord
B) Cerebrum
C) Diencephalon
D) Cerebellum
E) Brainstem

Question 7

Which of the following is not true of respiratory alkalosis?

A) It exists when the blood pH is >7.45.
B) It can result from an increase in the CO₂ level in the blood.
C) It can result in death, if the blood pH reaches 8.0 or above.
D) It causes vasoconstriction of the cerebral blood vessels, which decreases oxygen delivery to the brain.
E) All of these are true of respiratory alkalosis.

Question 8

Which of the following would not result in acidosis?

A) Rebreathing air from a paper bag
B) Hypoventilation
C) Breath holding
D) Hyperventilation
E) All of these could result in acidosis.

Question 9

Which of the following is not true of the respiratory irritant receptors?

A) Stimulation of these receptors can lead to coughing or sneezing.
B) Stimulation of the respiratory irritant receptors results in dilations in the bronchial tree.
C) Sensory impulses from the irritant receptors are transported by the vagus nerve.
D) Sensory impulses from the irritant receptors are transported to the dorsal respiratory group.
E) All of these are true of the respiratory irritant receptors.

Question 10

The central chemoreceptors for respiration are located in the ________; they monitor the blood concentration(s) of ________.

A) pons; oxygen
B) medulla oblongata; carbon dioxide and hydrogen ions
C) aortic and carotid arteries; oxygen
D) pons; carbon dioxide and hydrogen ions
E) medulla oblongata; oxygen

Question 11

The main generator of impulses for respiratory rate during eupnea is the

A) dorsal respiratory group (DRG),
B) pneumotaxic center.
C) ventral respiratory group (VRG).
D) pontine respiratory group (PRG).
E) hypothalamus.

Question 12

What is the result of the inflation reflex?

A) An increase in the duration of inspirations
B) An increase in the duration of expirations
C) A decrease in the duration of inspirations
D) A decrease in the duration of expirations
E) An increase in the duration of inspirations and a decrease in the duration of expirations

Question 13

During normal, quiet breathing, the expiratory muscles are only minimally involved in the process of respiration.

Question 14

What type(s) of muscle tissue make(s) up the muscles of inspiration and expiration?

A) Both consist of skeletal muscle.
B) Inspiratory muscles consist of skeletal muscle, and expiratory muscles consist of smooth muscle.
C) Inspiratory muscles consist of smooth muscle, and expiratory muscles consist of skeletal muscle.
D) Both consist of smooth muscle.
E) Inspiratory muscles consist of skeletal muscle, and expiratory muscles consist of cardiac muscle.

Question 15

During inspiration, the expiratory neurons of the ventral respiratory group (VRG) are being inhibited.

Question 16

Which of the following structures does not send input to the dorsal respiratory group?

A) Central chemoreceptors
B) Stretch receptors
C) Peripheral chemoreceptors
D) Irritant receptors
E) All of these structures send input to the dorsal respiratory group.

Question 17

The most significant factor in determining changes in the rate and depth of breathing is the blood concentration of oxygen.

Question 18

During normal, quiet breathing, inspirations last longer than expirations.