Question 1

Normal, resting exhalation/expiration of air from the lungs requires contraction of the exhalatory/expiratory intercostal muscles.

Accepted Answer

Normal, resting exhalation/expiration of air from the lungs is a passive process that doesn't require any muscle contraction. The relaxation of the diaphragm and the elastic recoil of the lung tissue are enough to push air out of the lungs. However, during forced exhalation/expiration, the internal intercostal muscles and the abdominal muscles contract to further reduce the volume of the thoracic cavity and increase the pressure, resulting in more air being forced out.

Question 2

Which of the following conditions would result in a systemic arterial P_O2 lower than is typical of a healthy person at sea level?

Accepted Answer

Traveling to high altitude decreases atmospheric pressure, resulting in lower inspired oxygen levels and subsequently lower arterial partial pressures of oxygen (PO2). This leads to systemic arterial P_O2 lower than is typical of a healthy person at sea level.

Question 3

Which correctly describes the cause of the increase in alveolar ventilation that occurs when a person ascends to high altitude?

Accepted Answer

As a person ascends to high altitude, the partial pressure of oxygen in inspired air decreases due to the reduction in total atmospheric pressure. This decrease in P_O2 of inspired air leads to a decrease in alveolar and arterial P_O2, which stimulates the peripheral chemoreceptors to increase alveolar ventilation. Additionally, the decrease in P_O2 can also lead to hypoxemia, which further stimulates ventilation through the peripheral chemoreceptors. Therefore, choice C is the correct answer describing the cause of increased alveolar ventilation at high altitude.

Question 4

Which of these does NOT increase during heavy exercise?

Accepted Answer

Arterial P_CO2 decreases during heavy exercise due to increased ventilation, which removes more carbon dioxide from the body.

Question 5

If the parietal pleura is cut during surgery, the lung on the side of the cut will expand and the chest wall will be compressed.

Accepted Answer

If the parietal pleura is cut, air will enter the pleural space, causing the lung to collapse (not expand) and the chest wall to expand (not compress).

Question 6

The diameter of the airways in normal lungs is generally great enough that little resistance is offered to airflow.

Accepted Answer

The diameter of the airways in normal lungs is generally great enough to allow for easy airflow with minimal resistance. However, in certain conditions such as asthma or chronic obstructive pulmonary disease (COPD), the airway diameter may become narrowed, resulting in increased resistance to airflow.

Question 7

During inhalation/inspiration, the total alveolar volume decreases.

Accepted Answer

During inhalation/inspiration, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity and lungs, which in turn causes a decrease in alveolar pressure and an increase in alveolar volume.

Question 8

In a normal person at rest, the part of the respiratory cycle in which no air is flowing through the airways and the respiratory muscles are relaxed is at the end of inhalation/inspiration, prior to exhalation/expiration.

Accepted Answer

The answer of In a normal person at rest, the...

Question 9

If the nerves from the carotid and aortic bodies are cut, which of these would occur?

Accepted Answer

The answer of If the nerves from the carotid and...

Question 10

The process of ventilation includes both the transport of gases by bulk flow and the diffusion of gases into and out of the blood.

Accepted Answer

The answer of The process of ventilation includes both the...

Question 11

Emphysema is a disease characterized by low lung compliance, obstructed airways, and ventilation-perfusion inequality.

Accepted Answer

Emphysema is characterized by high lung compliance due to the destruction of alveolar walls, which leads to obstructed airways and ventilation-perfusion inequality, but not low lung compliance.

Question 12

According to Boyle's law, the pressure exerted by a constant number of gas molecules in a container is inversely proportional to the volume of the container. Therefore, increasing the volume of the container will cause a decrease in its pressure.

Accepted Answer

According to Boyle's law, as the volume of the container increases, the pressure exerted by a constant number of gas molecules in the container decreases. Therefore, increasing the volume of the container will cause a decrease in its pressure, making the statement true.

Question 13

Following strenuous exercise, blood levels of lactic acid are ________ compared to pre-exercise levels. This change in acid concentration causes a reflex ________ in ventilation by activating ________.

Accepted Answer

Following strenuous exercise, blood levels of lactic acid increase, which causes a reflex increase in ventilation. This change is primarily detected by peripheral chemoreceptors that are sensitive to changes in blood pH.

Question 14

During inhalation/inspiration, the diaphragm contracts and the alveolar pressure is less than atmospheric pressure; during exhalation/expiration, the diaphragm relaxes and the alveolar pressure is greater than atmospheric pressure.

Accepted Answer

This is correct. During inspiration, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity and causing the alveolar pressure to decrease, which allows air to flow into the lungs. During expiration, the diaphragm relaxes and moves upward, decreasing the volume of the thoracic cavity and causing the alveolar pressure to increase, which forces air out of the lungs.

Question 15

Which is characteristic of a person chronically suffering from hypoxic hypoxia?

Accepted Answer

Chronic hypoxic hypoxia leads to increased production of red blood cells to compensate for low oxygen levels, resulting in a higher-than-normal hematocrit.

Question 16

Which of the following statements regarding hypoxia is correct?

Accepted Answer

Exposure to high altitude results in hypoxic hypoxia due to reduced atmospheric oxygen pressure, leading to lower oxygen availability for the body.

Question 17

Which of these would tend to increase ventilation?

Accepted Answer

Breathing air with increased P_CO2 triggers chemoreceptors in the brain to increase ventilation in order to remove excess CO2.

Question 18

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

Accepted Answer

Increased concentrations of lactic acid stimulate ventilation primarily by acting on peripheral chemoreceptors, which are sensitive to changes in blood pH and can increase ventilation in response to acidosis.

Question 19

The diaphragm is a large sheet of smooth muscle that separates the thoracic cavity from the abdomen.

Accepted Answer

The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity, but it is primarily composed of skeletal muscle, not smooth muscle.

Question 20

Infants born prematurely frequently develop respiratory distress syndrome of the newborn because they have too few alveoli to exchange O₂ and CO₂ efficiently.

Accepted Answer

Respiratory distress syndrome in premature infants is primarily due to insufficient surfactant production, not the number of alveoli. Surfactant reduces surface tension in the lungs, preventing alveolar collapse.

Quiz 13: Respiratory Physiology

Normal, resting exhalation/expiration of air from the lungs requires contraction of the exhalatory/expiratory intercostal muscles.

Which of the following conditions would result in a systemic arterial P_O2 lower than is typical of a healthy person at sea level?

Which correctly describes the cause of the increase in alveolar ventilation that occurs when a person ascends to high altitude?

Which of these does NOT increase during heavy exercise?

If the parietal pleura is cut during surgery, the lung on the side of the cut will expand and the chest wall will be compressed.

The diameter of the airways in normal lungs is generally great enough that little resistance is offered to airflow.

During inhalation/inspiration, the total alveolar volume decreases.

In a normal person at rest, the part of the respiratory cycle in which no air is flowing through the airways and the respiratory muscles are relaxed is at the end of inhalation/inspiration, prior to exhalation/expiration.

If the nerves from the carotid and aortic bodies are cut, which of these would occur?

The process of ventilation includes both the transport of gases by bulk flow and the diffusion of gases into and out of the blood.

Emphysema is a disease characterized by low lung compliance, obstructed airways, and ventilation-perfusion inequality.

According to Boyle's law, the pressure exerted by a constant number of gas molecules in a container is inversely proportional to the volume of the container. Therefore, increasing the volume of the container will cause a decrease in its pressure.

Following strenuous exercise, blood levels of lactic acid are compared to pre-exercise levels. This change in acid concentration causes a reflex in ventilation by activating .

During inhalation/inspiration, the diaphragm contracts and the alveolar pressure is less than atmospheric pressure; during exhalation/expiration, the diaphragm relaxes and the alveolar pressure is greater than atmospheric pressure.

Which is characteristic of a person chronically suffering from hypoxic hypoxia?

Which of the following statements regarding hypoxia is correct?

Which of these would tend to increase ventilation?

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

The diaphragm is a large sheet of smooth muscle that separates the thoracic cavity from the abdomen.

Infants born prematurely frequently develop respiratory distress syndrome of the newborn because they have too few alveoli to exchange O₂ and CO₂ efficiently.

Quiz 13: Respiratory Physiology

Normal, resting exhalation/expiration of air from the lungs requires contraction of the exhalatory/expiratory intercostal muscles.

Which of the following conditions would result in a systemic arterial PO2 lower than is typical of a healthy person at sea level?

Which correctly describes the cause of the increase in alveolar ventilation that occurs when a person ascends to high altitude?

Which of these does NOT increase during heavy exercise?

If the parietal pleura is cut during surgery, the lung on the side of the cut will expand and the chest wall will be compressed.

The diameter of the airways in normal lungs is generally great enough that little resistance is offered to airflow.

During inhalation/inspiration, the total alveolar volume decreases.

In a normal person at rest, the part of the respiratory cycle in which no air is flowing through the airways and the respiratory muscles are relaxed is at the end of inhalation/inspiration, prior to exhalation/expiration.

If the nerves from the carotid and aortic bodies are cut, which of these would occur?

The process of ventilation includes both the transport of gases by bulk flow and the diffusion of gases into and out of the blood.

Emphysema is a disease characterized by low lung compliance, obstructed airways, and ventilation-perfusion inequality.

According to Boyle's law, the pressure exerted by a constant number of gas molecules in a container is inversely proportional to the volume of the container. Therefore, increasing the volume of the container will cause a decrease in its pressure.

Following strenuous exercise, blood levels of lactic acid are ________ compared to pre-exercise levels. This change in acid concentration causes a reflex ________ in ventilation by activating ________.

During inhalation/inspiration, the diaphragm contracts and the alveolar pressure is less than atmospheric pressure; during exhalation/expiration, the diaphragm relaxes and the alveolar pressure is greater than atmospheric pressure.

Which is characteristic of a person chronically suffering from hypoxic hypoxia?

Which of the following statements regarding hypoxia is correct?

Which of these would tend to increase ventilation?

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

The diaphragm is a large sheet of smooth muscle that separates the thoracic cavity from the abdomen.

Infants born prematurely frequently develop respiratory distress syndrome of the newborn because they have too few alveoli to exchange O2 and CO2 efficiently.

Which of the following conditions would result in a systemic arterial P_O2 lower than is typical of a healthy person at sea level?

Following strenuous exercise, blood levels of lactic acid are compared to pre-exercise levels. This change in acid concentration causes a reflex in ventilation by activating .

Infants born prematurely frequently develop respiratory distress syndrome of the newborn because they have too few alveoli to exchange O₂ and CO₂ efficiently.