Question

Which of the following statements regarding control of respiration is true?

Select one:

a. The diaphragm is innervated by the vagus nerve.

b. Inspiratory neurons from the ventral group stimulate the diaphragm to contract

c. During exercise, respiration is under conscious (voluntary) control.

d. Chemoreceptors in the lungs measure the amount of stretch and relay this info to the pontine respiratory group.

A normal expiration during quiet breathing:

Select one:

a. is an active process involving muscle contraction.

b. occurs when the diaphragm and external intercostal muscles relax.

c. is not affected by the elastic properties of the lungs.

d. requires more muscle contractions than inspiration.

e. occurs due to the contraction of the diaphragm and elevation of the ribs.

Question 33

After hyperventilating for several minutes:

Select one:

a. blood pH would drop and inhibit inspiration.

b. blood pH will rise and stimulate expiration.

c. O₂ in the lungs has not had time to diffuse into the blood.

d. the level of O₂ has increased and inhibits the inspiratory center.

e. the level of CO₂ decreases below the level necessary to stimulate the inspiratory center.

Answer 1

1. ANSWER: The diaphragm is innervated by vagus nerve, during exercise respiration is under consious control.

Reason: The diaphragm is innervated by vagus nerve which would cause to contract and relax the muscle. During exercise due to increased oxygen demand respiration becomes voluntary.

2. ANSWER: occurs when intercostal muscle and diaphragm relaxes.

Reason: diaphragm and intercostal muscle return to their original position during exhalation.

3. ANSWER: blood ph will rise and stimulate expiration.

Reason: during hyperventilation blood ph of the lerson increases due to the removal of co2 from blood resulting in increased expiration to the person.