Question 1

The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anhydrase.

Accepted Answer

The largest amount of carbon dioxide is transported in the bloodstream in the form of bicarbonate ions, not carbonic anhydrase. Carbonic anhydrase is an enzyme that helps convert carbon dioxide into bicarbonate ions.

Question 2

The average individual has 500 ml of residual volume in his lungs.

Accepted Answer

The average individual has approximately 1200 ml of residual volume in their lungs.

Question 3

The alveolar ventilation rate is the best index of effective ventilation.

Accepted Answer

The alveolar ventilation rate is the amount of air that actually reaches the alveoli per minute and is used for gas exchange. Therefore, it provides a better measure of effective ventilation than other measures such as tidal volume or minute ventilation.

Question 4

Nasal conchae mainly work on inhalation to warm and moisten air. They serve minor functions for exhalation.

Accepted Answer

The answer of Nasal conchae mainly work on inhalation to...

Question 5

Under certain conditions, the vocal folds act as a sphincter that prevents air passage.

Accepted Answer

The vocal folds can close tightly to prevent air passage, for example during activities such as holding one's breath or swallowing.

Question 6

As carbon dioxide enters systemic blood, it causes more oxygen to dissociate from hemoglobin (the Haldane effect), which in turn allows more CO₂ to combine with hemoglobin and more bicarbonate ions to be generated (the Bohr effect).

Accepted Answer

The statement incorrectly attributes the Haldane and Bohr effects. The Bohr effect describes how increased CO₂ and H⁺ concentrations facilitate oxygen release from hemoglobin, while the Haldane effect describes how deoxygenated blood increases its capacity to carry CO₂.

Question 7

Tracheal obstruction is life threatening.

Accepted Answer

Tracheal obstruction can lead to difficulty breathing and ultimately result in death if not treated immediately.

Question 8

Atelectasis (lung collapse) renders the lung useless for ventilation.

Accepted Answer

Atelectasis occurs when the air sacs in the lungs (alveoli) collapse, leading to a loss of function in that area of the lung for ventilation.

Question 9

Smoking diminishes ciliary action and eventually destroys the cilia.

Accepted Answer

Smoking is a major cause of damage to the cilia, which are the tiny hair-like structures on the lining of the respiratory tract that help to clear mucus and debris from the lungs. Over time, smoking can impair ciliary action and eventually lead to their destruction, which can have serious health consequences.

Question 10

Oxygenated hemoglobin releases oxygen more readily when the pH is more basic.

Accepted Answer

Oxygenated hemoglobin releases oxygen more readily when the pH is more acidic, not basic. This is because a low pH (acidic environment) promotes the unloading of oxygen from hemoglobin to the surrounding tissues.

Question 11

Increased temperature results in decreased O₂ unloading from hemoglobin.

Accepted Answer

Increased temperature actually results in increased O₂ unloading from hemoglobin, as it causes hemoglobin to release oxygen more readily to meet the higher metabolic demands.

Question 12

The paired lungs occupy all of the thoracic cavity.

Accepted Answer

The answer of The paired lungs occupy all of the...

Question 13

The parietal pleura lines the thoracic wall.

Accepted Answer

The parietal pleura lines the thoracic wall, while the visceral pleura covers the lungs.

Question 14

Valsalva's maneuver involves closing off the glottis (preventing expiration) while contracting the muscles of expiration, causing an increase in intra-abdominal pressure.

Accepted Answer

The statement accurately describes Valsalva's maneuver.

Question 15

The Hering-Breuer reflex is a potentially dangerous response that may cause overinflation of the lung.

Accepted Answer

The answer of The Hering-Breuer reflex is a potentially dangerous...

Question 16

Strong emotions and pain acting through the limbic system activate sympathetic centers in the hypothalamus, thus modulating respiratory rate and depth by sending signals to the respiratory centers.

Accepted Answer

The statement accurately describes the role of the limbic system in modulating respiratory function during emotional states and pain.

Question 17

Dalton's law states that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture.

Accepted Answer

This is the correct statement of Dalton's law.

Question 18

Labored breathing is termed dyspnea.

Accepted Answer

Labored breathing is a medical term used to describe difficulty breathing or shortness of breath, which is called dyspnea.

Question 19

During normal quiet breathing, approximately 750 ml of air moves into and out of the lungs with each breath.

Accepted Answer

During normal quiet breathing, approximately 500 ml of air moves into and out of the lungs with each breath, not 750 ml. This volume is referred to as the tidal volume.

Question 20

In chronic bronchitis, mucus production is decreased and this leads to the inflammation and fibrosis of the mucosal lining of the bronchial tree.

Accepted Answer

In chronic bronchitis, mucus production is actually increased, leading to inflammation and fibrosis of the mucosal lining of the bronchial tree.

Quiz 21: The Respiratory System