ESTUDYR
AP II FINAL 2025 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED
SUCCESS WITH DETAILED RATIONALES
1. Which respiratory center causes slow, deep breathing when stimulated?
A. Pneumotaxic center
B. Dorsal respiratory group
C. Apneustic center
D. Ventral respiratory group
– Rationale: The apneustic center, located in the lower pons, promotes prolonged inspiratory
“holds,” resulting in deep, slow breaths.
2. Which of the following is not a primary mechanism controlling breathing?
A. Carbon dioxide levels in the blood
B. Blood pH
C. Oxygen partial pressure
D. Blood glucose levels
– Rationale: Respiratory drive is regulated by CO₂ (via pH), O₂, and neural feedback—not by
blood glucose.
3. The maximal amount of air that can be inhaled in addition to the tidal volume is the:
A. Expiratory reserve volume
B. Residual volume
C. Inspiratory reserve volume
D. Functional residual capacity
– Rationale: Inspiratory reserve volume (IRV) is the extra volume above normal tidal inhalation.
4. The carina, the point where the trachea branches into bronchi, is located at the level of the:
A. Cricoid cartilage
B. T5 vertebra
C. Thyroid cartilage
D. Sternal angle
– Rationale: The carina lies posterior to the sternal angle at approximately T5 in the thorax.
5. External respiration is best described as:
A. Gas exchange in tissues
B. Conversion of CO₂ to bicarbonate
C. Diffusion of gases between alveoli and blood
D. Cellular O₂ utilization
– Rationale: External respiration refers to gas exchange across the respiratory membrane in the
lungs.
, ESTUDYR
6. Overinflation of the lungs is prevented by activation of:
A. Central chemoreceptors
B. Hering–Breuer reflex via pulmonary stretch receptors
C. Baroreceptors in carotid sinuses
D. Pulmonary stretch receptor stimulation
– Rationale: Stretch receptors in airway smooth muscle trigger the Hering–Breuer reflex to
terminate inspiration.
7. The volume of air moved in and out of the lungs with each normal breath is the:
A. Vital capacity
B. Tidal volume
C. Total lung capacity
D. Residual volume
– Rationale: Tidal volume (TV) is the amount inhaled or exhaled during a restful breath.
8. Internal respiration refers to:
A. Gas exchange at the alveoli
B. Gas exchange between blood and tissue cells
C. Cellular metabolism of O₂
D. Diffusion of inspired air
– Rationale: Internal respiration describes O₂ and CO₂ exchange at systemic capillaries.
9. The majority of carbon dioxide is carried in the blood as:
A. Dissolved CO₂
B. Carbaminohemoglobin
C. Bicarbonate ion (HCO₃⁻)
D. Carbonic acid
– Rationale: Over 70% of CO₂ is transported as bicarbonate after reacting with water.
10. Which two respiratory centers coordinate normal, quiet breathing?
A. Apneustic and pneumotaxic groups
B. Dorsal and ventral respiratory groups
C. Pneumotaxic center and central chemoreceptors
D. Ventral group and peripheral chemoreceptors
– Rationale: The dorsal and ventral groups in the medulla regulate rhythm and depth of
inspiration and expiration.
11. The normal adult respiratory rate is:
A. 8–10 breaths/min
B. 12–18 breaths/min
C. 20–24 breaths/min
D. 25–30 breaths/min
– Rationale: A resting rate of 12–18 breaths per minute is typical for healthy adults.
AP II FINAL 2025 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED
SUCCESS WITH DETAILED RATIONALES
1. Which respiratory center causes slow, deep breathing when stimulated?
A. Pneumotaxic center
B. Dorsal respiratory group
C. Apneustic center
D. Ventral respiratory group
– Rationale: The apneustic center, located in the lower pons, promotes prolonged inspiratory
“holds,” resulting in deep, slow breaths.
2. Which of the following is not a primary mechanism controlling breathing?
A. Carbon dioxide levels in the blood
B. Blood pH
C. Oxygen partial pressure
D. Blood glucose levels
– Rationale: Respiratory drive is regulated by CO₂ (via pH), O₂, and neural feedback—not by
blood glucose.
3. The maximal amount of air that can be inhaled in addition to the tidal volume is the:
A. Expiratory reserve volume
B. Residual volume
C. Inspiratory reserve volume
D. Functional residual capacity
– Rationale: Inspiratory reserve volume (IRV) is the extra volume above normal tidal inhalation.
4. The carina, the point where the trachea branches into bronchi, is located at the level of the:
A. Cricoid cartilage
B. T5 vertebra
C. Thyroid cartilage
D. Sternal angle
– Rationale: The carina lies posterior to the sternal angle at approximately T5 in the thorax.
5. External respiration is best described as:
A. Gas exchange in tissues
B. Conversion of CO₂ to bicarbonate
C. Diffusion of gases between alveoli and blood
D. Cellular O₂ utilization
– Rationale: External respiration refers to gas exchange across the respiratory membrane in the
lungs.
, ESTUDYR
6. Overinflation of the lungs is prevented by activation of:
A. Central chemoreceptors
B. Hering–Breuer reflex via pulmonary stretch receptors
C. Baroreceptors in carotid sinuses
D. Pulmonary stretch receptor stimulation
– Rationale: Stretch receptors in airway smooth muscle trigger the Hering–Breuer reflex to
terminate inspiration.
7. The volume of air moved in and out of the lungs with each normal breath is the:
A. Vital capacity
B. Tidal volume
C. Total lung capacity
D. Residual volume
– Rationale: Tidal volume (TV) is the amount inhaled or exhaled during a restful breath.
8. Internal respiration refers to:
A. Gas exchange at the alveoli
B. Gas exchange between blood and tissue cells
C. Cellular metabolism of O₂
D. Diffusion of inspired air
– Rationale: Internal respiration describes O₂ and CO₂ exchange at systemic capillaries.
9. The majority of carbon dioxide is carried in the blood as:
A. Dissolved CO₂
B. Carbaminohemoglobin
C. Bicarbonate ion (HCO₃⁻)
D. Carbonic acid
– Rationale: Over 70% of CO₂ is transported as bicarbonate after reacting with water.
10. Which two respiratory centers coordinate normal, quiet breathing?
A. Apneustic and pneumotaxic groups
B. Dorsal and ventral respiratory groups
C. Pneumotaxic center and central chemoreceptors
D. Ventral group and peripheral chemoreceptors
– Rationale: The dorsal and ventral groups in the medulla regulate rhythm and depth of
inspiration and expiration.
11. The normal adult respiratory rate is:
A. 8–10 breaths/min
B. 12–18 breaths/min
C. 20–24 breaths/min
D. 25–30 breaths/min
– Rationale: A resting rate of 12–18 breaths per minute is typical for healthy adults.
