Physiology of Respiration Quizzes: Master Respiratory System Functions

Question 1

During inhalation, what is the primary function of the diaphragm?

Accepted Answer

Contracts, expanding the thoracic cavity and drawing air into the lungs

Answer

Relaxes, shrinking the thoracic cavity and expelling air from the lungs

Answer

Contracts, shrinking the thoracic cavity and drawing air into the lungs

Question 2

Inspiration is the process of gas movement into the lungs. Which statement accurately describes this action?

Accepted Answer

Passive movement of gas into the lungs as intrathoracic pressure decreases

Answer

Active movement of gas into the lungs as intrathoracic pressure increases

Answer

Passive movement of gas out of the lungs as intrathoracic pressure decreases

Answer

Active movement of gas out of the lungs as intrathoracic pressure increases

Question 3

Gas exchange between the bloodstream and the atmosphere occurs primarily in which structure?

Accepted Answer

Alveoli

Answer

Bronchi

Answer

Trachea

Answer

Pharynx

Question 4

Hemoglobin's main function in the blood is to:

Accepted Answer

Transport oxygen

Answer

Transport carbon dioxide

Answer

Regulate pH

Answer

Facilitate gas diffusion

Question 5

Hypoxia refers to:

Accepted Answer

Deficiency of oxygen in tissues

Answer

Excess of carbon dioxide in tissues

Answer

Inadequate blood flow to tissues

Answer

Impaired gas exchange

Question 6

The most sensitive indicator of adequate alveolar ventilation is:

Accepted Answer

Partial pressure of arterial carbon dioxide (PaCO2)

Answer

Arterial pH

Answer

Partial pressure of arterial oxygen (PaO2)

Answer

Bicarbonate level

Question 7

The primary reason for oxygen therapy is:

Accepted Answer

Hypoxemia

Answer

Hypercapnia

Answer

Acidosis

Answer

Cardiac arrhythmias

Question 8

Which chemoreceptor, located in the brain, primarily detects changes in cerebrospinal fluid pH and influences respiratory rate?

Accepted Answer

Central chemoreceptors

Answer

Carotid body

Answer

Peripheral chemoreceptors

Question 9

How does the respiratory system primarily regulate blood pH levels?

Accepted Answer

By adjusting the rate of alveolar ventilation

Answer

By modifying the bicarbonate concentration in the blood

Answer

By secreting hormones that affect renal function

Question 10

A 65-year-old male presents with a persistent cough producing yellow-green sputum, fever, and shortness of breath. What is the most likely diagnosis?

Accepted Answer

Pneumonia

Answer

Bronchitis

Answer

Tuberculosis

Answer

Asthma

Question 11

What is the primary stimulus for increasing the rate of ventilation?

Accepted Answer

Increased PaCO2

Answer

Increased PaO2

Answer

Increased pH

Answer

Increased bicarbonate

Question 12

Which of the following is NOT a function of the surfactant?

Accepted Answer

Facilitating diffusion of oxygen

Answer

Reducing surface tension in the alveoli

Answer

Preventing alveolar collapse

Answer

Increasing lung compliance

Question 13

What is the anatomical dead space?

Accepted Answer

The volume of gas in the conducting airways

Answer

The volume of gas that participates in gas exchange

Answer

The volume of gas that is expired

Answer

The volume of gas that is inspired

Question 14

Which of the following respiratory disorders is characterized by chronic inflammation of the bronchioles?

Accepted Answer

Chronic bronchitis

Answer

Asthma

Answer

Emphysema

Answer

Pulmonary fibrosis

Question 15

What is the principal function of hemoglobin?

Accepted Answer

Transporting O2

Answer

Transporting CO2

Answer

Buffering pH

Answer

Regulating ventilation

Question 16

What is the primary mechanism for regulating the pH of the blood?

Accepted Answer

Respiratory compensation

Answer

Metabolic compensation

Answer

Renal compensation

Answer

Hormonal compensation

Question 17

Which factor does NOT influence the partial pressure of oxygen in the alveoli?

Accepted Answer

Pulmonary blood flow

Answer

Atmospheric pressure

Answer

Alveolar ventilation

Answer

Diffusion capacity of the alveolar-capillary membrane

Question 18

What is the main function of the intercostal muscles?

Accepted Answer

Expand and contract the thoracic cavity

Answer

Pump blood from the right ventricle to the pulmonary artery

Answer

Elevate the diaphragm

Answer

Facilitate gas exchange in the lungs

Question 19

What is the primary stimulus for increased ventilation during exercise?

Accepted Answer

Increased lactate concentration

Answer

Increased body temperature

Answer

Increased arterial carbon dioxide tension

Answer

Increased arterial oxygen tension

Question 20

Which lung volume is measured as the volume of air remaining in the lungs after a maximal expiration?

Accepted Answer

Residual volume

Answer

Tidal volume

Answer

Inspiratory reserve volume

Answer

Vital capacity

Question 21

Which mechanism is responsible for the movement of carbon dioxide from the tissues into the bloodstream?

Accepted Answer

Diffusion

Answer

Convection

Answer

Active transport

Answer

Facilitated diffusion

Question 22

Which characteristic is NOT typically seen in asthma?

Accepted Answer

Progressive destruction of lung tissue

Answer

Reversible airway obstruction

Answer

Bronchial hyperresponsiveness

Answer

Increased mucus production

Question 23

Which mechanism primarily causes the development of respiratory acidosis?

Accepted Answer

Decreased carbon dioxide elimination

Answer

Increased carbon dioxide production

Answer

Increased bicarbonate concentration

Answer

Decreased bicarbonate concentration

Question 24

In the context of prolonged ventilation-perfusion mismatch, which of the following arterial blood gas abnormalities is most likely to occur in areas with a high ventilation-to-perfusion ratio?

Accepted Answer

Respiratory alkalosis

Answer

Respiratory acidosis

Answer

Metabolic alkalosis

Answer

Metabolic acidosis

Question 25

Inhaled corticosteroids (ICS) are widely used in asthma management. What is their primary mode of action?

Accepted Answer

Reducing inflammation

Answer

Inhibiting phosphodiesterase

Answer

Promoting bronchodilation

Answer

Exerting anticholinergic effects

Question 26

A patient presents with shortness of breath. Their spirometry results show: 
- FVC: 4.5L (85% predicted) 
- FEV1: 3.5L (70% predicted) 
- FEV1/FVC ratio: 0.78

What is the most likely diagnosis?

Accepted Answer

Obstructive lung disease

Answer

Normal lung function

Answer

Restrictive lung disease

Answer

Mixed lung disease

Question 27

Which of the following is the primary factor that determines the rate of alveolar ventilation?

Accepted Answer

Ventilatory drive

Answer

Airway resistance

Answer

Pulmonary blood flow

Answer

Respiratory compliance

Question 28

Which of the following is the primary determinant of the partial pressure of oxygen in arterial blood (PaO2)?

Accepted Answer

Alveolar ventilation and the alveolar-to-arterial oxygen tension gradient

Answer

Pulmonary blood flow and body temperature

Answer

Cardiac output and hemoglobin concentration

Question 29

Which of the following volumes represents the volume of air that can be inhaled from the resting end-expiratory level?

Accepted Answer

Inspiratory capacity (IC)

Answer

Expiratory reserve volume

Answer

Tidal volume

Question 30

Which of the following is NOT a function of the respiratory system?

Accepted Answer

Secretion of digestive enzymes

Answer

pH regulation

Answer

Acid-base balance

Answer

Gas exchange

Question 31

Which of the following is the primary determinant of the partial pressure of carbon dioxide in arterial blood (PaCO2)?

Accepted Answer

Alveolar ventilation and the alveolar-to-arterial carbon dioxide tension gradient

Answer

Cardiac output and hemoglobin concentration

Answer

Pulmonary blood flow and body temperature

Question 32

Which of the following characteristics is most commonly associated with obstructive lung diseases?

Accepted Answer

Increased airway resistance

Answer

Reduced lung volumes

Answer

Normal diffusion capacity

Answer

Decreased lung compliance

Question 33

Which of the following conditions is the most common cause of acute respiratory distress syndrome (ARDS)?

Accepted Answer

Sepsis

Answer

Asthma

Answer

COPD

Answer

Pneumonia

Question 34

Within the pulmonary capillaries, which gases are predominantly exchanged?

Accepted Answer

Oxygen and carbon dioxide

Answer

Carbon dioxide only

Answer

Oxygen only

Answer

Nitrogen and carbon dioxide

Question 35

In the context of respiratory gas transport, what is the primary role of hemoglobin?

Accepted Answer

Binding to and transporting oxygen

Answer

Regulating blood pH

Answer

Facilitating gas exchange in the lungs

Answer

Transporting carbon dioxide as bicarbonate ions

Question 36

Which of the following is NOT a physiological function of the respiratory system?

Accepted Answer

Production of urine

Answer

Elimination of carbon dioxide

Answer

Production of sound for speech

Answer

Regulation of acid-base balance

Question 37

Which mechanism is primarily responsible for maintaining blood pH?

Accepted Answer

Control of carbon dioxide levels

Answer

Regulation of bicarbonate levels

Answer

Control of potassium levels

Answer

Control of sodium levels

Question 38

A characteristic feature of obstructive lung diseases is:

Accepted Answer

Elevated airway resistance

Answer

Enhanced lung compliance

Answer

Reduced residual volume

Answer

Increased vital capacity

Question 39

In healthy individuals, what is the typical range of partial pressure of oxygen in arterial blood?

Accepted Answer

80-100 mmHg

Answer

40-60 mmHg

Answer

120-140 mmHg

Answer

160-180 mmHg

Question 40

Which of the following is a known risk factor for the development of lung cancer?

Accepted Answer

Tobacco smoking

Answer

Regular exercise

Answer

Adequate sleep

Answer

Balanced diet

Question 41

The primary function of the respiratory center located in the medulla oblongata is to regulate:

Accepted Answer

Breathing rhythm and depth

Answer

Blood pressure

Answer

Coordination of movement

Answer

Body temperature

Question 42

Which of the following is NOT a primary function of the respiratory system?

Accepted Answer

Nutrient absorption

Answer

Gas exchange

Answer

Ventilation

Answer

Regulation of blood pH

Question 43

The partial pressure of oxygen in the alveoli is approximately:

Accepted Answer

100 mmHg

Answer

150 mmHg

Answer

70 mmHg

Answer

40 mmHg

Question 44

Which of the following muscles is involved in expiration, rather than inspiration?

Accepted Answer

Triceps brachii

Answer

Diaphragm

Answer

Scalenes

Answer

Internal intercostal muscles

Question 45

The primary stimulus for rapid respiratory control is:

Accepted Answer

Arterial carbon dioxide concentration

Answer

Arterial oxygen concentration

Answer

pH

Answer

Temperature

Question 46

The surfactant produced by type II pneumocytes:

Accepted Answer

Reduces surface tension in the alveoli and facilitates gas exchange

Answer

Increases respiratory rate

Answer

Enhances surfactant production

Answer

Facilitates gas exchange

Question 47

Which of the following is the primary site of oxygen and carbon dioxide exchange?

Accepted Answer

Alveoli

Answer

Trachea

Answer

Bronchi

Answer

Nasal cavity

Question 48

The Bohr effect refers to:

Accepted Answer

The decrease in oxygen affinity of hemoglobin with increasing carbon dioxide concentration, facilitating oxygen delivery to tissues

Answer

The decrease in oxygen affinity of hemoglobin with increasing temperature

Answer

The increase in oxygen affinity of hemoglobin with increasing pH

Question 49

Which of the following is a measure of the amount of air moved in and out of the lungs per minute?

Accepted Answer

Minute ventilation

Answer

Tidal volume

Answer

Vital capacity

Answer

Inspiratory capacity

Question 50

The diffusion of gases across the respiratory membrane is:

Accepted Answer

Passive and driven by concentration gradients

Answer

Active

Answer

Facilitated

Answer

Secondary active