Question 1

The nose serves all of the following functions EXCEPT ________.

Accepted Answer

The function of the nose does not include being the direct initiator of the cough reflex. The cough reflex is caused by irritation to the respiratory system, which can occur beyond the nasal passageway.

Question 2

Which of the choices below is NOT a factor that promotes oxygen binding to and dissociation from hemoglobin?

Accepted Answer

The number of red blood cells does not directly impact the ability of hemoglobin to bind to or dissociate from oxygen. The other factors listed (temperature, partial pressure of oxygen, partial pressure of carbon dioxide) all play a role in promoting or inhibiting oxygen binding to and dissociation from hemoglobin.

Question 3

Spirometry results reveal a vital capacity of two liters which is well below the predicted value of five liters.This suggests which disorder?

Accepted Answer

A vital capacity of two liters which is well below the predicted value of five liters suggests a restrictive disease. This means that the lungs are unable to fully expand due to stiffness in the lungs, chest wall, or muscles involved in breathing. Emphysema and obstructive pulmonary disease are types of obstructive lung diseases characterized by difficulty exhaling air, while asthma is a chronic inflammation of the airways that causes wheezing, coughing, and shortness of breath.

Question 4

Which of the disorders below is characterized by destruction of the walls of the alveoli producing abnormally large air spaces that remain filled with air during exhalation?

Accepted Answer

Emphysema is a chronic obstructive pulmonary disorder characterized by destruction of the walls of the alveoli, resulting in abnormally large air spaces that remain filled with air during exhalation.

Question 5

Which of the following is an appropriate response to carbon monoxide (CO)poisoning?

Accepted Answer

Hyperbaric oxygen therapy increases the amount of oxygen dissolved in the blood, which helps to replace the CO bound to hemoglobin and speeds up the clearance of CO from the body. Other options listed may not effectively address CO poisoning. Hyperventilation can cause respiratory alkalosis and does not necessarily increase CO elimination. Slow breathing into a paper bag may help with hyperventilation-induced respiratory alkalosis but does not address CO poisoning. Application of bicarbonate ions may help in reducing acidosis caused by CO-induced tissue hypoxia, but it does not directly facilitate the removal of CO from hemoglobin.

Question 6

Select the correct statement about oxygen transport in blood.

Accepted Answer

C) A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal. This is because during increased physical activity, tissues consume more oxygen, lowering the saturation level of hemoglobin with oxygen in the blood returning to the lungs compared to resting conditions.

Question 7

Factors that influence the rate and depth of breathing include ________.

Accepted Answer

The answer of Factors that influence the rate and depth...

Question 8

Select the correct statement about the physical factors influencing pulmonary ventilation.

Accepted Answer

As alveolar surface tension increases, additional muscle action will be required. Surfactant actually decreases alveolar surface tension, allowing for easier expansion of the lungs during inhalation. A lung that is less elastic will require more muscle action to perform adequate ventilation, not less. A decrease in compliance (i.e. increased stiffness of the lung tissue) will also result in a decrease in ventilation.

Question 9

The respiratory membrane is a combination of ________.

Accepted Answer

The respiratory membrane is composed of the alveolar wall and the capillary wall, along with their fused basement membranes. This is where gas exchange occurs between the air in the alveoli and the blood in the capillaries. Choice A is incorrect because respiratory bronchioles are not part of the respiratory membrane. Choice C is incorrect because alveolar sacs are part of the alveoli and therefore part of the respiratory membrane, but respiratory bronchioles are not. Choice D is incorrect because atria are part of the heart and not involved in gas exchange.

Question 10

Most inspired particles such as dust fail to reach the lungs because of the ________.

Accepted Answer

The ciliated mucous lining in the nose helps to trap and remove particles from the air before it reaches the lungs, preventing them from entering the respiratory system.

Question 11

Which of the following does NOT influence hemoglobin saturation?

Accepted Answer

BPG, temperature, and partial pressure of carbon dioxide all influence hemoglobin saturation by altering the affinity of hemoglobin for oxygen. Nitric oxide also binds to hemoglobin, but it does not alter its affinity for oxygen.

Question 12

Which of the following is responsible for holding the lungs to the thorax wall are ________.

Accepted Answer

The visceral pleura adheres to the surface of the lungs, while the parietal pleura lines the thorax wall. The space between them, the pleural cavity, contains a small amount of pleural fluid. Together, the surface tension from pleural fluid and negative pressure in the pleural cavity creates a suction that holds the lungs to the thorax wall.

Question 13

Inspiratory capacity is ________.

Accepted Answer

Inspiratory capacity is the maximum amount of air that can be inspired after a tidal expiration. It is calculated by adding the tidal volume (the amount of air inspired and expired during normal breathing) to the inspiratory reserve volume (the additional amount of air that can be inhaled after a normal inhalation).

Question 14

According to the oxygen-hemoglobin dissociation curve,PO2 in the lungs of 100 mm Hg results in Hb being 98% saturated.At high altitude,there is less O2.At a PO2 in the lungs of 80 mm Hg,Hb would be ________ saturated.

Accepted Answer

According to the oxygen-hemoglobin dissociation curve, a PO2 of 80 mm Hg results in approximately 95% Hb saturation. This is due to the decreased availability of oxygen at high altitudes. Therefore, the correct answer is D (95%).

Question 15

Which of the following is INCORRECT?

Accepted Answer

This statement is incorrect. According to the equation for gas flow, which is Gas Flow = Pressure Gradient / Resistance, the pressure gradient is divided by the resistance, not the other way around.

Question 16

The symptoms of hyperventilation may be averted by breathing into a paper bag because it ________.

Accepted Answer

Breathing into a paper bag helps retain carbon dioxide in the blood, which can help alleviate the symptoms of hyperventilation. When someone hyperventilates, they exhale too much carbon dioxide and this leads to a decrease in carbon dioxide concentration in the blood. Breathing into a paper bag helps to increase the carbon dioxide concentration in the blood, which can help reduce the symptoms of hyperventilation.

Question 17

The erythrocyte (red blood cell)count increases after a while when an individual goes from a low to a high altitude because the ________.

Accepted Answer

At higher altitudes, the concentration of oxygen and/or total atmospheric pressure is lower, which leads to an increase in erythrocyte count to compensate for the reduced oxygen availability.

Question 18

Select the correct statement about the neural mechanisms of respiratory control.

Accepted Answer

The answer of Select the correct statement about the neural...

Question 19

Which center is located in the pons?

Accepted Answer

The pontine respirator group (PRG) is located in the pons and is responsible for regulating the pattern and depth of breathing. Therefore, C is the best choice. The inspiratory center and expiratory center are located in the medulla oblongata, not the pons. While there are pacemaker neurons located in the brainstem, they are not specifically located in the pons.

Question 20

For inspiration of air,which of the following happens first?

Accepted Answer

When we inhale, the first thing that happens is that the diaphragm muscles contract and move downward, causing the size of the thoracic cavity to increase. This action causes the rib cage to expand, and the intercostal muscles between the ribs contract to further enlarge the thoracic cavity. This expansion of the thoracic cavity results in a decreased intrathoracic pressure relative to the atmospheric pressure, therefore allowing air to flow into the lungs. Finally, intrapulmonary pressure drops, and air (gases) flows into the lungs.

Quiz 22: The Respiratory System