Breathing and Exchange of Gases MCQ. Practice multiple choice questions on Breathing and Exchange of Gases, covering the human respiratory system, mechanism, gas transport and regulation.
Breathing and Exchange of Gases MCQ – Mock Online Test
Question 1: What is the primary purpose of breathing in organisms?
A. To release excess heat from the body.
B. To exchange oxygen and carbon dioxide with the environment.
C. To provide a source of energy for cellular processes.
D. To remove waste products from the body.
B. To exchange oxygen and carbon dioxide with the environment. Breathing facilitates the uptake of oxygen for energy production and the removal of carbon dioxide, a waste product of cellular respiration.
Question 2: Which gas is utilized by organisms to break down molecules and produce energy?
A. Carbon dioxide (CO₂)
B. Nitrogen (N₂)
C. Oxygen (O₂)
D. Hydrogen (H₂)
C. Oxygen (O₂). Oxygen is essential for cellular respiration, where it is used to break down glucose and other molecules to generate energy.
Question 3: What is the byproduct of energy production in cells?
A. Oxygen (O₂)
B. Water (H₂O)
C. Carbon dioxide (CO₂)
D. Nitrogen (N₂)
C. Carbon dioxide (CO₂). Carbon dioxide is produced during cellular respiration as a waste product.
Question 4: How do lower invertebrates like sponges and flatworms exchange gases?
A. Through specialized respiratory organs like lungs.
B. By simple diffusion across their body surface.
C. Using a network of tracheal tubes.
D. Through their moist cuticle.
B. By simple diffusion across their body surface. Lower invertebrates have simple body structures that allow for direct gas exchange with the environment.
Question 5: What respiratory mechanism do earthworms utilize?
A. Tracheal tubes
B. Gills
C. Lungs
D. Moist cuticle
D. Moist cuticle. Earthworms exchange gases through their skin, which is kept moist for efficient diffusion.
Question 6: How do insects carry out gas exchange?
A. Lungs
B. Gills
C. Tracheal tubes
D. Skin
C. Tracheal tubes. Insects have a network of tubes called tracheae that deliver oxygen directly to their tissues.
Question 7: What is the function of the nasal chamber in the respiratory system?
A. Gas exchange
B. Sound production
C. Filtering, warming, and moistening inhaled air
D. Swallowing food
C. Filtering, warming, and moistening inhaled air. The nasal chamber conditions the air before it enters the lungs.
Question 8: The pharynx is a common passage for:
A. Food and air
B. Air and water
C. Food and water
D. Air and blood
A. Food and air. The pharynx is part of both the respiratory and digestive systems.
Question 9: Which structure is responsible for sound production?
A. Trachea
B. Bronchi
C. Larynx
D. Pharynx
C. Larynx. The larynx contains the vocal cords, which vibrate to produce sound.
Question 10: What is the role of the epiglottis?
A. To produce sound.
B. To prevent food from entering the trachea.
C. To filter inhaled air.
D. To facilitate gas exchange.
B. To prevent food from entering the trachea. The epiglottis acts as a flap that covers the trachea during swallowing.
Question 11: The trachea is also known as the:
A. Food pipe
B. Voice box
C. Windpipe
D. Air sac
C. Windpipe. The trachea is the tube that carries air from the larynx to the bronchi.
Question 12: What are the two tubes that branch from the trachea called?
A. Bronchioles
B. Alveoli
C. Bronchi
D. Capillaries
C. Bronchi. The trachea divides into two main bronchi, one leading to each lung.
Question 13: Bronchi further divide into smaller tubes called:
A. Alveoli
B. Bronchioles
C. Capillaries
D. Pleura
B. Bronchioles. Bronchioles are the finer branches of the bronchi within the lungs.
Question 14: Where does the actual exchange of gases take place in the lungs?
A. Bronchi
B. Trachea
C. Alveoli
D. Pleura
C. Alveoli. Alveoli are tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged.
Question 15: Which organs are the primary sites for gas exchange in the human body?
A. Kidneys
B. Lungs
C. Heart
D. Liver
B. Lungs. The lungs are specifically designed for efficient gas exchange.
Question 16: What is the membrane that encloses the lungs called?
A. Pericardium
B. Peritoneum
C. Pleura
D. Meninges
C. Pleura. The pleura is a double-layered membrane that surrounds each lung.
Question 17: Which part of the respiratory system is responsible for transporting air but not involved in gas exchange?
A. Respiratory part
B. Conducting part
C. Alveolar ducts
D. Alveoli
B. Conducting part. The conducting part includes structures like the trachea, bronchi, and bronchioles that carry air to the alveoli.
Question 18: Which part of the respiratory system is responsible for the exchange of gases?
A. Conducting part
B. Respiratory part
C. Bronchioles
D. Trachea
B. Respiratory part. The respiratory part includes the alveoli where gas exchange occurs.
Question 19: Where are the lungs located within the body?
A. Cranial cavity
B. Abdominal cavity
C. Thoracic chamber
D. Pelvic cavity
C. Thoracic chamber. The thoracic chamber, or chest cavity, houses and protects the lungs.
Question 20: What separates the thoracic cavity from the abdominal cavity?
A. Ribs
B. Sternum
C. Diaphragm
D. Intercostal muscles
C. Diaphragm. The diaphragm is a dome-shaped muscle that forms the floor of the thoracic cavity.
Question 21: What is the process of taking in atmospheric air called?
A. Expiration
B. Inspiration
C. Ventilation
D. Diffusion
B. Inspiration. Inspiration is the active process of drawing air into the lungs.
Question 22: What is the process of releasing air from the lungs called?
A. Inspiration
B. Expiration
C. Diffusion
D. Osmosis
B. Expiration. Expiration is the process of expelling air from the lungs.
Question 23: What drives the movement of air into and out of the lungs?
A. Temperature difference
B. Concentration gradient
C. Pressure gradient
D. Osmotic pressure
C. Pressure gradient. Air flows from an area of high pressure to low pressure.
Question 24: Which muscle plays a major role in breathing by altering the volume of the thoracic cavity?
A. Biceps
B. Diaphragm
C. Quadriceps
D. Triceps
B. Diaphragm. The diaphragm is the primary muscle involved in breathing.
Question 25: What is the function of the intercostal muscles during breathing?
A. They contract to decrease the volume of the thoracic cavity.
B. They relax to allow for expiration.
C. They assist in expanding and contracting the rib cage.
D. They have no role in breathing.
C. They assist in expanding and contracting the rib cage. The intercostal muscles help change the thoracic cavity’s size during breathing.
Question 26: What does tidal volume refer to?
A. The maximum volume of air a person can inhale.
B. The volume of air remaining in the lungs after a normal exhalation.
C. The volume of air inhaled or exhaled during a normal breath.
D. The additional volume of air inhaled after a deep breath.
C. The volume of air inhaled or exhaled during a normal breath. Tidal volume is the amount of air exchanged during quiet breathing.
Question 27: What is the additional volume of air that can be forcibly inhaled after a normal inhalation called?
A. Tidal volume
B. Inspiratory reserve volume
C. Expiratory reserve volume
D. Residual volume
B. Inspiratory reserve volume. It’s the extra air that can be inhaled beyond the normal tidal volume.
Question 28: What is the additional volume of air that can be forcibly exhaled after a normal exhalation called?
A. Tidal volume
B. Inspiratory reserve volume
C. Expiratory reserve volume
D. Residual volume
C. Expiratory reserve volume. It’s the extra air that can be exhaled beyond the normal tidal volume.
Question 29: What is the volume of air that remains in the lungs even after a forceful exhalation called?
A. Tidal volume
B. Inspiratory reserve volume
C. Expiratory reserve volume
D. Residual volume
D. Residual volume. This air ensures that the lungs don’t collapse completely.
Question 30: What does inspiratory capacity represent?
A. The total volume of air a person can exhale.
B. The volume of air remaining in the lungs after a normal exhalation.
C. The maximum volume of air a person can inhale after a normal exhalation.
D. The additional volume of air inhaled after a deep breath.
C. The maximum volume of air a person can inhale after a normal exhalation. It includes tidal volume and inspiratory reserve volume.
Question 31: What does expiratory capacity represent?
A. The total volume of air a person can inhale.
B. The volume of air remaining in the lungs after a normal exhalation.
C. The maximum volume of air a person can exhale after a normal inhalation.
D. The additional volume of air inhaled after a deep breath.
C. The maximum volume of air a person can exhale after a normal inhalation. It includes tidal volume and expiratory reserve volume.
Question 32: What does functional residual capacity represent?
A. The total volume of air a person can inhale.
B. The volume of air remaining in the lungs after a normal exhalation.
C. The maximum volume of air a person can exhale after a normal inhalation.
D. The additional volume of air inhaled after a deep breath.
B. The volume of air remaining in the lungs after a normal exhalation. It includes expiratory reserve volume and residual volume.
Question 33: What does vital capacity represent?
A. The total volume of air a person can inhale.
B. The volume of air remaining in the lungs after a normal exhalation.
C. The maximum volume of air a person can exhale after a forceful inhalation.
D. The additional volume of air inhaled after a deep breath.
C. The maximum volume of air a person can exhale after a forceful inhalation. It includes inspiratory reserve volume, tidal volume, and expiratory reserve volume.
Question 34: What does total lung capacity represent?
A. The total volume of air a person can inhale.
B. The volume of air remaining in the lungs after a normal exhalation.
C. The maximum volume of air a person can exhale after a forceful inhalation.
D. The total volume of air the lungs can hold after a maximum inhalation.
D. The total volume of air the lungs can hold after a maximum inhalation. It includes all lung volumes.
Question 35: What are the primary sites of gas exchange in the lungs?
A. Bronchi
B. Trachea
C. Alveoli
D. Pleura
C. Alveoli. Alveoli are tiny air sacs surrounded by capillaries for efficient gas exchange.
Question 36: By what process are oxygen and carbon dioxide exchanged in the lungs and tissues?
A. Active transport
B. Osmosis
C. Diffusion
D. Filtration
C. Diffusion. Gases move from areas of high concentration to low concentration.
Question 37: What is the term for the pressure exerted by an individual gas within a mixture of gases?
A. Vapor pressure
B. Partial pressure
C. Osmotic pressure
D. Absolute pressure
B. Partial pressure. It determines the movement of each gas independently.
Question 38: What constitutes the diffusion membrane through which gases are exchanged in the alveoli?
A. A thick layer of connective tissue
B. A single layer of epithelial cells
C. The alveolar wall, capillary wall, and their basement membranes
D. A layer of smooth muscle cells
C. The alveolar wall, capillary wall, and their basement membranes. This thin membrane allows for efficient gas exchange.
Question 39: What is the primary medium for the transport of oxygen and carbon dioxide in the body?
A. Lymph
B. Blood
C. Interstitial fluid
D. Cerebrospinal fluid
B. Blood. Blood carries oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs.
Question 40: Which respiratory pigment in red blood cells binds to oxygen?
A. Myoglobin
B. Chlorophyll
C. Hemoglobin
D. Cytochrome
C. Hemoglobin. Hemoglobin greatly increases the oxygen-carrying capacity of blood.
Question 41: What is formed when oxygen binds with hemoglobin?
A. Carbaminohemoglobin
B. Carboxyhemoglobin
C. Oxyhemoglobin
D. Deoxyhemoglobin
C. Oxyhemoglobin. This is the form in which oxygen is transported in the blood.
Question 42: What type of curve illustrates the relationship between the partial pressure of oxygen and the percentage saturation of hemoglobin with oxygen?
A. Linear curve
B. Exponential curve
C. Sigmoid curve
D. Hyperbolic curve
C. Sigmoid curve. The oxygen dissociation curve shows how oxygen saturation changes with varying oxygen partial pressures.
Question 43: How is a small percentage of carbon dioxide transported in the blood?
A. Dissolved in plasma
B. As bicarbonate ions
C. Bound to hemoglobin as carbaminohemoglobin
D. As carbonic acid
C. Bound to hemoglobin as carbaminohemoglobin. This is a minor transport mechanism for carbon dioxide.
Question 44: Which enzyme catalyzes the formation of bicarbonate ions from carbon dioxide and water in the blood?
A. Carbonic anhydrase
B. Catalase
C. Amylase
D. Lipase
A. Carbonic anhydrase. This enzyme speeds up the conversion of carbon dioxide to bicarbonate ions.
Question 45: What is the major form in which carbon dioxide is transported in the blood?
A. Dissolved in plasma
B. As bicarbonate ions
C. Bound to hemoglobin as carbaminohemoglobin
D. As carbonic acid
B. As bicarbonate ions. This is the most efficient way to transport carbon dioxide in the blood.
Question 46: Which system in the body plays a major role in regulating respiration?
A. Endocrine system
B. Digestive system
C. Neural system
D. Excretory system
C. Neural system. The nervous system controls the rate and depth of breathing.
Question 47: Where is the respiratory rhythm center located?
A. Cerebellum
B. Medulla oblongata
C. Hypothalamus
D. Cerebral cortex
B. Medulla oblongata. The medulla oblongata in the brainstem controls the basic rhythm of breathing.
Question 48: Which center in the brain can moderate the functions of the respiratory rhythm center?
A. Apneustic center
B. Pneumotaxic center
C. Cardiovascular center
D. Thermoregulatory center
B. Pneumotaxic center. The pneumotaxic center helps fine-tune the breathing pattern.
Question 49: Which area in the brain is highly sensitive to changes in CO₂ and hydrogen ion (H⁺) concentrations?
A. Chemosensitive area
B. Visual cortex
C. Auditory cortex
D. Motor cortex
A. Chemosensitive area. This area helps regulate breathing based on blood CO₂ and H⁺ levels.
Question 50: Where are the receptors that can detect changes in CO₂ and H⁺ concentrations located?
A. Aortic arch and carotid artery
B. Pulmonary veins and arteries
C. Vena cava and aorta
D. Cerebral arteries
A. Aortic arch and carotid artery. These receptors send signals to the brain to adjust breathing.
Question 51: What is a common respiratory disorder characterized by inflammation and narrowing of the airways?
A. Pneumonia
B. Bronchitis
C. Asthma
D. Emphysema
C. Asthma. Asthma often involves wheezing and difficulty breathing.
Question 52: Which respiratory disorder is characterized by damage to the alveolar walls, leading to reduced gas exchange?
A. Asthma
B. Bronchitis
C. Pneumonia
D. Emphysema
D. Emphysema. Emphysema is a chronic obstructive pulmonary disease (COPD).
Question 53: What type of respiratory disorders can be caused by long-term exposure to dust, fumes, or chemicals in the workplace?
A. Infectious respiratory disorders
B. Occupational respiratory disorders
C. Allergies
D. Autoimmune disorders
B. Occupational respiratory disorders. These disorders are specific to certain work environments.
Question 54: Which of the following is NOT a characteristic of asthma?
A. Inflammation of bronchi and bronchioles
B. Wheezing sound during breathing
C. Difficulty in breathing
D. Damage to alveolar walls
D. Damage to alveolar walls. Damage to alveolar walls is a characteristic of emphysema, not asthma.
Question 55: Which of the following is a major cause of emphysema?
A. Exposure to dust
B. Cigarette smoking
C. Allergies
D. Bacterial infection
B. Cigarette smoking. Cigarette smoking is a leading cause of emphysema.
Question 56: What is the primary cause of occupational respiratory disorders?
A. Genetic predisposition
B. Exposure to allergens
C. Exposure to workplace pollutants
D. Viral infections
C. Exposure to workplace pollutants. Occupational respiratory disorders are caused by inhaling harmful substances in the workplace.
Question 57: Which of the following is a common symptom of occupational respiratory disorders?
A. Fever
B. Cough
C. Skin rash
D. Headache
B. Cough. Cough is a common symptom of various respiratory disorders, including occupational ones.
Question 58: Which of the following occupations is NOT typically associated with a high risk of occupational respiratory disorders?
A. Coal mining
B. Construction work
C. Office work
D. Sandblasting
C. Office work. Office work typically does not involve exposure to high levels of respiratory hazards.
Question 59: What is the purpose of wearing protective masks in industries with high dust levels?
A. To prevent the spread of infectious diseases.
B. To reduce the risk of occupational respiratory disorders.
C. To improve breathing efficiency.
D. To prevent allergies.
B. To reduce the risk of occupational respiratory disorders. Protective masks filter out dust and other harmful particles.
Question 60: Which of the following is NOT a common type of occupational respiratory disorder?
A. Asthma
B. Pneumonia
C. Silicosis
D. Asbestosis
B. Pneumonia. Pneumonia is usually caused by an infection, not occupational exposure.
Question 61: What is the term for the scarring of lung tissue caused by long-term exposure to dust or other irritants?
A. Emphysema
B. Bronchitis
C. Pneumothorax
D. Fibrosis
D. Fibrosis. Fibrosis is the formation of excess fibrous tissue in the lungs, leading to stiffness and reduced function.
Question 62: Which of the following is NOT a preventive measure for occupational respiratory disorders?
A. Wearing protective equipment
B. Regular medical check-ups
C. Taking antibiotics
D. Ensuring good ventilation in the workplace
C. Taking antibiotics. Antibiotics are not effective against occupational respiratory disorders as they are not caused by bacterial infections.
Question 63: What is the primary function of the respiratory system?
A. To produce sound
B. To filter blood
C. To exchange gases between the body and the environment
D. To digest food
C. To exchange gases between the body and the environment. The respiratory system facilitates the uptake of oxygen and release of carbon dioxide.
Question 64: Which of the following is NOT a component of the conducting part of the respiratory system?
A. Trachea
B. Bronchi
C. Alveoli
D. Pharynx
C. Alveoli. Alveoli are part of the respiratory part, where gas exchange occurs.
Question 65: What is the role of pleural fluid?
A. To facilitate gas exchange
B. To reduce friction between the lungs and the chest wall
C. To produce sound
D. To filter air
B. To reduce friction between the lungs and the chest wall. Pleural fluid allows the lungs to move smoothly during breathing.
Question 66: Which of the following is NOT a step involved in respiration?
A. Breathing
B. Digestion
C. Transport of gases
D. Diffusion of gases
B. Digestion. Digestion is part of the digestive system, not the respiratory system.
Question 67: What is the primary muscle involved in inspiration?
A. Diaphragm
B. Biceps
C. Triceps
D. Quadriceps
A. Diaphragm. The diaphragm contracts during inhalation, increasing the volume of the thoracic cavity.
Question 68: What is the term for the pressure within the lungs?
A. Atmospheric pressure
B. Intrapleural pressure
C. Intrapulmonary pressure
D. Hydrostatic pressure
C. Intrapulmonary pressure. Intrapulmonary pressure changes during breathing to allow for air movement.
Question 69: What is the additional volume of air a person can inspire by a forcible inspiration called?
A. Tidal volume
B. Inspiratory reserve volume
C. Expiratory reserve volume
D. Residual volume
B. Inspiratory reserve volume. It is the extra volume of air that can be inhaled forcefully after a normal inspiration.
Question 70: What is the volume of air remaining in the lungs even after a forcible expiration called?
A. Tidal volume
B. Inspiratory reserve volume
C. Expiratory reserve volume
D. Residual volume
D. Residual volume. It ensures that the lungs do not collapse completely.
Question 71: What happens to the diaphragm during inhalation?
A. It relaxes and moves upwards.
B. It contracts and moves downwards.
C. It remains stationary.
D. It contracts and moves upwards.
B. It contracts and moves downwards. The diaphragm’s contraction increases the volume of the thoracic cavity, allowing for lung expansion.
Question 72: What happens to the intercostal muscles during inhalation?
A. They relax.
B. They contract.
C. They remain inactive.
D. They partially contract.
B. They contract. The intercostal muscles contract to lift the rib cage, further expanding the thoracic cavity.
Question 73: What happens to the volume of the thoracic cavity during exhalation?
A. It increases.
B. It decreases.
C. It remains the same.
D. It fluctuates rapidly.
B. It decreases. The relaxation of the diaphragm and intercostal muscles reduces the thoracic cavity volume, expelling air from the lungs.
Question 74: What is the relationship between lung volume and intrapulmonary pressure?
A. As lung volume increases, intrapulmonary pressure increases.
B. As lung volume increases, intrapulmonary pressure decreases.
C. Lung volume and intrapulmonary pressure are unrelate
D. D. They have a complex, non-linear relationship.
B. As lung volume increases, intrapulmonary pressure decreases. This pressure difference drives air into the lungs during inhalation.
Question 75: What is the primary factor that drives the diffusion of gases across the respiratory membrane?
A. Temperature difference
B. Partial pressure gradient
C. Molecular weight of the gases
D. Solubility of the gases in water
B. Partial pressure gradient. Gases move from an area of higher partial pressure to an area of lower partial pressure.
Question 76: What is the partial pressure of oxygen (pO₂) in the alveoli compared to the pulmonary capillaries?
A. Higher in the alveoli.
B. Higher in the pulmonary capillaries.
C. Equal in both.
D. Variable and unpredictable.
A. Higher in the alveoli. This difference in pO₂ drives the diffusion of oxygen from the alveoli into the blood.
Question 77: What is the partial pressure of carbon dioxide (pCO₂) in the tissues compared to the systemic capillaries?
A. Higher in the tissues.
B. Higher in the systemic capillaries.
C. Equal in both.
D. Variable and unpredictable.
A. Higher in the tissues. This difference in pCO₂ drives the diffusion of carbon dioxide from the tissues into the blood.
Question 78: What is the approximate percentage of oxygen transported in the blood bound to hemoglobin?
A. 25%
B. 50%
C. 75%
D. 97%
D. 97%. Hemoglobin significantly increases the blood’s oxygen-carrying capacity.
Question 79: What is the main form in which carbon dioxide is transported in the blood?
A. Dissolved in plasma
B. Bound to hemoglobin
C. As bicarbonate ions
D. As carbonic acid
C. As bicarbonate ions. Bicarbonate ions in the plasma are the primary means of carbon dioxide transport.
Question 80: What is the role of carbonic anhydrase in carbon dioxide transport?
A. It binds carbon dioxide to hemoglobin.
B. It catalyzes the conversion of carbon dioxide and water to carbonic acid.
C. It transports bicarbonate ions into the red blood cells.
D. It releases oxygen from hemoglobin.
B. It catalyzes the conversion of carbon dioxide and water to carbonic acid. Carbonic acid then dissociates into bicarbonate ions.
Question 81: What happens to the oxygen dissociation curve when the pH of the blood decreases (becomes more acidic)?
A. It shifts to the left.
B. It shifts to the right.
C. It remains unchange
D. D. It becomes steeper.
B. It shifts to the right. A decrease in pH (increased acidity) reduces hemoglobin’s affinity for oxygen, promoting oxygen release in the tissues.
Question 82: What is the Bohr effect?
A. The effect of pH on oxygen binding to hemoglobin.
B. The effect of temperature on oxygen binding to hemoglobin.
C. The effect of carbon dioxide on oxygen binding to hemoglobin.
D. All of the above.
D. All of the above. The Bohr effect encompasses the influence of pH, temperature, and carbon dioxide on hemoglobin’s oxygen affinity.
Question 83: What is the Haldane effect?
A. The effect of oxygen on carbon dioxide binding to hemoglobin.
B. The effect of pH on carbon dioxide binding to hemoglobin.
C. The effect of temperature on carbon dioxide binding to hemoglobin.
D. The effect of carbon dioxide on oxygen binding to hemoglobin.
A. The effect of oxygen on carbon dioxide binding to hemoglobin. Oxygenation of blood in the lungs decreases its affinity for carbon dioxide, facilitating its release.
Question 84: What is the role of the enzyme carbonic anhydrase in carbon dioxide transport?
A. It converts carbon dioxide to carbonic acid.
B. It binds carbon dioxide to hemoglobin.
C. It transports bicarbonate ions into the red blood cells.
D. It releases oxygen from hemoglobin.
A. It converts carbon dioxide to carbonic acid. This reaction occurs in the red blood cells, allowing for efficient carbon dioxide transport as bicarbonate ions.
Question 85: Where is the respiratory rhythm center located in the brain?
A. Cerebrum
B. Cerebellum
C. Medulla oblongata
D. Hypothalamus
C. Medulla oblongata. The medulla oblongata controls the basic rhythm of breathing.
Question 86: What is the role of the pneumotaxic center in respiration?
A. It initiates breathing.
B. It increases the rate of breathing.
C. It decreases the rate of breathing.
D. It can moderate the functions of the respiratory rhythm center.
D. It can moderate the functions of the respiratory rhythm center. The pneumotaxic center helps fine-tune the breathing pattern.
Question 87: What is the primary stimulus for changes in the rate and depth of breathing?
A. Blood oxygen levels
B. Blood carbon dioxide levels
C. Blood glucose levels
D. Blood pressure
B. Blood carbon dioxide levels. An increase in blood carbon dioxide levels triggers an increase in breathing rate and depth.
Question 88: Where are the peripheral chemoreceptors that can detect changes in blood oxygen levels located?
A. Aortic arch and carotid bodies
B. Pulmonary veins
C. Vena cava
D. Cerebral arteries
A. Aortic arch and carotid bodies. These chemoreceptors send signals to the brain to adjust breathing in response to changes in blood oxygen levels.
Question 89: What is the effect of increased carbon dioxide levels on the pH of the cerebrospinal fluid (CSF)?
A. It increases the pH (makes it more alkaline).
B. It decreases the pH (makes it more acidic).
C. It has no effect on the pH.
D. It causes fluctuations in the pH.
B. It decreases the pH (makes it more acidic). Carbon dioxide reacts with water in the CSF to form carbonic acid, which dissociates and lowers the pH.
Question 90: What is the response of the respiratory system to an increase in the acidity of the CSF?
A. Breathing becomes slower and shallower.
B. Breathing becomes faster and deeper.
C. Breathing rate remains unchange
D. D. Breathing becomes irregular.
B. Breathing becomes faster and deeper. The chemosensitive area in the medulla oblongata detects the increased acidity and stimulates the respiratory centers to increase ventilation.
Question 91: What is the role of the aortic and carotid bodies in the regulation of respiration?
A. They detect changes in blood pressure.
B. They detect changes in blood oxygen levels.
C. They detect changes in blood carbon dioxide levels.
D. They detect changes in blood glucose levels.
B. They detect changes in blood oxygen levels. These peripheral chemoreceptors are sensitive to decreases in blood oxygen levels and signal the brain to increase ventilation.
Question 92: What is the primary mechanism by which respiration is regulated during exercise?
A. Increased blood oxygen levels
B. Increased blood carbon dioxide levels
C. Increased blood lactic acid levels
D. All of the above
D. All of the above. Multiple factors, including increased carbon dioxide, lactic acid, and signals from the motor cortex, contribute to increased ventilation during exercise.
Question 93: What is the effect of high altitude on respiration?
A. Breathing becomes slower and shallower.
B. Breathing becomes faster and deeper.
C. Breathing rate remains unchange
D. D. Breathing becomes irregular.
B. Breathing becomes faster and deeper. The lower partial pressure of oxygen at high altitudes triggers an increase in ventilation to compensate for the reduced oxygen availability.
Question 94: Which of the following is NOT a disorder of the respiratory system?
A. Asthma
B. Emphysema
C. Arthritis
D. Pneumonia
C. Arthritis. Arthritis is a joint disorder, not a respiratory disorder.
Question 95: What is the primary cause of emphysema?
A. Bacterial infection
B. Viral infection
C. Smoking
D. Allergies
C. Smoking. Smoking is a major risk factor for emphysema, which involves damage to the alveolar walls.
Question 96: What is a common symptom of asthma?
A. Wheezing
B. Cough
C. Shortness of breath
D. All of the above
D. All of the above. Asthma is characterized by airway inflammation and constriction, leading to various respiratory symptoms.
Question 97: What is the primary cause of occupational respiratory disorders?
A. Genetic factors
B. Exposure to allergens
C. Exposure to workplace pollutants
D. Infections
C. Exposure to workplace pollutants. Occupational respiratory disorders result from inhaling harmful substances in the work environment.
Question 98: Which of the following is a preventive measure for occupational respiratory disorders?
A. Wearing protective equipment
B. Ensuring good ventilation in the workplace
C. Regular medical check-ups
D. All of the above
D. All of the above. These measures help reduce exposure to harmful substances and promote early detection of any respiratory problems.
Question 99: What is the leading cause of lung cancer?
A. Exposure to asbestos
B. Smoking
C. Air pollution
D. Genetic factors
B. Smoking. Smoking is the most significant risk factor for lung cancer.
Question 100: Which of the following is NOT a function of the respiratory system?
A. Gas exchange
B. pH regulation
C. Sound production
D. Nutrient absorption
D. Nutrient absorption. Nutrient absorption is a function of the digestive system, not the respiratory system.
