Gas Exchange: Interactive Quizzes for Physiology Students

Question 1

Which of the following is NOT a partial pressure of a gas in the respiratory system?

Accepted Answer

pH

Answer

PCO₂

Answer

P₂O₂

Question 2

Which of the following factors does NOT influence the rate of diffusion of gases across the alveolar-capillary membrane?

Accepted Answer

Flow rate of the blood

Answer

Surface area of the membrane

Answer

Thickness of the membrane

Answer

Pressure gradient of the gases

Question 3

Which respiratory condition is characterized by airway obstruction and wheezing?

Accepted Answer

Asthma

Answer

Emphysema

Answer

Pneumonia

Answer

Pulmonary fibrosis

Question 4

The partial pressure of oxygen in arterial blood is approximately:

Accepted Answer

80-100 mmHg

Answer

40-60 mmHg

Answer

100-120 mmHg

Answer

120-140 mmHg

Question 5

Which enzyme catalyzes the conversion of carbon dioxide and water into carbonic acid?

Accepted Answer

Carbonic anhydrase

Answer

Acetylcholinesterase

Answer

Catalase

Answer

Peroxidase

Question 6

The main function of hemoglobin in gas transport is to:

Accepted Answer

Carry oxygen

Answer

Carry carbon dioxide

Answer

Regulate pH

Answer

Facilitate diffusion

Question 7

Which condition arises when the rate of ventilation exceeds the metabolic demand, leading to a decrease in arterial carbon dioxide levels?

Accepted Answer

Respiratory alkalosis

Answer

Respiratory acidosis

Answer

Metabolic alkalosis

Answer

Metabolic acidosis

Question 8

Which of the following is the primary buffer system responsible for maintaining the pH balance of blood?

Accepted Answer

Bicarbonate buffer system

Answer

Phosphate buffer system

Answer

Hemoglobin buffer system

Answer

Protein buffer system

Question 9

Which factor does NOT influence the rate of gas diffusion across the alveolar-capillary membrane?

Accepted Answer

Cardiac output

Answer

Surface area of the membrane

Answer

Thickness of the membrane

Answer

Partial pressure gradient of the gases

Question 10

What is the primary role of hemoglobin in oxygen transport?

Accepted Answer

To bind oxygen molecules and facilitate their delivery to tissues

Answer

To release oxygen molecules where they are needed in the body

Answer

To transport carbon dioxide as carbaminohemoglobin

Answer

To regulate blood pH

Question 11

Where does gas exchange primarily occur in the lungs?

Accepted Answer

Alveoli

Answer

Bronchioles

Answer

Trachea

Answer

Pharynx

Question 12

Which of the following is the primary role of hemoglobin in the body?

Accepted Answer

To transport oxygen from the lungs to the tissues

Answer

To transport carbon dioxide from the tissues to the lungs

Answer

To regulate the pH of the blood

Answer

To control body temperature

Question 13

What is the normal partial pressure of oxygen in arterial blood?

Accepted Answer

95 mmHg

Answer

80 mmHg

Answer

110 mmHg

Answer

125 mmHg

Question 14

What is the term for the movement of carbon dioxide from the tissues to the lungs?

Accepted Answer

Diffusion

Answer

Ventilation

Answer

Perfusion

Answer

Respiration

Question 15

What is the primary mechanism by which the lungs regulate blood pH?

Accepted Answer

Exhalation of H+

Answer

Inhalation of HCO3-

Answer

Reabsorption of HCO3-

Answer

Secretion of H+

Question 16

What is the most common cause of respiratory failure?

Accepted Answer

Pneumonia

Answer

Asthma

Answer

Emphysema

Answer

Pulmonary embolism

Question 17

What is the recommended first-line treatment for an acute asthma exacerbation?

Accepted Answer

Inhaled beta2-agonist

Answer

Oral corticosteroids

Answer

Intravenous fluids

Answer

Nasal decongestant

Question 18

Which factor is considered the primary regulator of ventilation?

Accepted Answer

Arterial PCO2

Answer

Plasma bicarbonate concentration

Answer

Arterial pH

Answer

Arterial PO2

Question 19

Which of the following characteristics applies to the pulmonary circulation?

Accepted Answer

Lower pressure compared to the systemic circulation

Answer

Higher pressure compared to the systemic circulation

Answer

Carries oxygenated blood

Question 20

Which factor primarily limits the rate of oxygen diffusion from the alveoli into the bloodstream?

Accepted Answer

Diffusion distance

Answer

Red blood cell count

Answer

Hemoglobin concentration

Answer

Ventilation-perfusion ratio

Question 21

What is the usual pH range of arterial blood in a healthy individual?

Accepted Answer

7.35 - 7.45

Answer

7.50 - 7.90

Answer

6.80 - 7.20

Answer

8.00 - 8.40

Question 22

Which is the main function of the surfactant produced in the lungs?

Accepted Answer

To reduce surface tension in the alveoli

Answer

To increase lung compliance

Answer

To promote gas exchange

Answer

To prevent alveolar collapse