A) External gas exchange → Gas transport → Internal gas exchange → Pulmonary ventilation
B) Pulmonary ventilation → External gas exchange → Gas transport → Internal gas exchange
C) Gas transport → Pulmonary ventilation → Internal gas exchange → External gas exchange
D) Internal gas exchange → Gas transport → External gas exchange → Pulmonary ventilation
Correct Answer: Pulmonary ventilation → External gas exchange → Gas transport → Internal gas
exchange
Rationale: Respiration involves four sequential phases: pulmonary ventilation (air movement
in/out of lungs), external gas exchange (between alveoli and blood), gas transport in blood, and
internal gas exchange (between blood and tissues). This sequence ensures oxygen delivery and
carbon dioxide removal .
2. The nasal cavity, pharynx, larynx, trachea, bronchi, and alveoli are all structures of which body
system?
A) Cardiovascular system
B) Respiratory system
C) Digestive system
D) Lymphatic system
Correct Answer: Respiratory system
Rationale: These structures form the major anatomical components of the respiratory system,
which work together to conduct air and facilitate gas exchange. The trachea and bronchi form
the lower conducting airways, while alveoli are the primary sites of gas exchange with the blood
.
,3. Which heart chamber receives deoxygenated blood from the body via the superior and
inferior vena cavae?
A) Left atrium
B) Left ventricle
C) Right atrium
D) Right ventricle
Correct Answer: Right atrium
Rationale: The right atrium is the receiving chamber for deoxygenated blood returning from the
systemic circulation. It collects blood from the superior and inferior vena cavae and the
coronary sinus before pumping it to the right ventricle for delivery to the lungs .
4. A heart rate of more than 100 beats per minute is medically defined as which of the
following?
A) Bradycardia
B) Tachycardia
C) Normal sinus rhythm
D) Heart block
Correct Answer: Tachycardia
Rationale: Tachycardia is the clinical term for a resting heart rate exceeding 100 beats per
minute. This can result from various causes including exercise, fever, anemia, or cardiac
arrhythmias. The opposite condition, bradycardia, is defined as a rate below 60 beats per
minute .
5. What is the primary role of the atrioventricular (AV) valves during ventricular contraction?
, A) To allow blood to flow from the ventricles into the arteries
B) To prevent the backflow of blood from the ventricles into the atria
C) To regulate the heart rate by controlling electrical impulses
D) To direct blood flow from the right ventricle to the lungs
Correct Answer: To prevent the backflow of blood from the ventricles into the atria
Rationale: The AV valves (tricuspid and mitral) close during ventricular systole to prevent
regurgitation of blood back into the atria. This ensures that blood is ejected forward into the
pulmonary artery and aorta. Valve dysfunction can lead to murmurs and reduced cardiac
efficiency .
6. A nurse is assessing a patient who presents with a hoarse vocal quality. Which term best
describes this finding?
A) Dysphagia
B) Dysphonia
C) Dysarthria
D) Aphasia
Correct Answer: Dysphonia
Rationale: Dysphonia refers to an abnormality in voice quality, such as hoarseness. Dysphagia is
difficulty swallowing. Dysarthria is slurred speech due to motor weakness. Aphasia is impaired
language comprehension or production, typically from brain injury .
7. Which phase of the cell cycle is characterized by DNA replication?
A) G₁ phase
B) S phase