ATI LPN
Questions on Respiratory System Questions
Question 1 of 5
Which of the following statements is true about the entry of air into the lungs?
Correct Answer: A
Rationale: Air enters the lungs via the mouth and nose, passing through the pharynx, larynx, trachea (windpipe), and bronchi. The esophagus and gullet handle food, not air confusing them with airways is anatomically incorrect. 'Windpipe and pores' misrepresents skin's role; respiration isn't cutaneous in humans. The nervous system controls breathing, not air entry. This oral-nasal pathway filters and conditions air, a basic respiratory process, ensuring lung protection and efficient gas exchange, a fundamental concept in airway anatomy and clinical airway management.
Question 2 of 5
Which of the following type of muscle contains the largest number of mitochondria per cell?
Correct Answer: C
Rationale: Cardiac muscle has the most mitochondria per cell, reflecting its relentless energy demand beating nonstop, it relies on aerobic metabolism, rich in mitochondria for ATP production from oxygen and nutrients. Smooth muscle, in vessels or gut, has fewer, suited to slower, sustained action. Skeletal muscle varies more in endurance fibers, less in sprinters but averages below cardiac. 'Same number' ignores specialization. Cardiac cells' mitochondrial density (up to 35% of volume) supports constant work, a hallmark of its design, key in heart failure where energy deficits impair function.
Question 3 of 5
Which part of the brain contains the cardiovascular center that regulates heart rate?
Correct Answer: C
Rationale: The medulla oblongata houses the cardiovascular center, regulating heart rate via autonomic outputs parasympathetic (vagus) slows it, sympathetic accelerates it, responding to baroreceptors and chemoreceptors. The midbrain handles reflexes, not rate. The cerebrum governs higher functions, not direct control. The cerebellum coordinates movement, not heart. The medulla's integration of blood pressure and CO2 data ensures homeostasis, a vital autonomic hub, critical in conditions like brain stem injury where rate control fails, affecting survival.
Question 4 of 5
A corrective cardiac procedure in which a large piece of a patient's own latissimus dorsi muscle is wrapped around the heart and stimulated by an implanted pacemaker to assist the pumping action of a damaged heart.
Correct Answer: D
Rationale: Cardiomyoplasty uses the latissimus dorsi muscle, wrapped around a failing heart and paced electrically, to aid pumping an older technique for severe heart failure. Myocardial infarction is heart attack damage, not a procedure. Tetralogy of Fallot is a congenital defect. Cardiomyopathy is disease, not repair. This muscle wrap boosts contractility, key in end-stage failure management, though less common now with ventricular assist devices, a historical cardiac support method.
Question 5 of 5
Of the four parts of respiration, the part when oxygen and carbon dioxide are exchanged in the capillaries lining the alveoli in the lungs, is:
Correct Answer: B
Rationale: External respiration (B) is the exchange of O₂ and CO₂ between alveolar air and pulmonary capillaries, per the key and physiology texts. Pulmonary ventilation (A) is breathing air movement in/out of lungs (e.g., 500 mL tidal volume). Transport of respiratory gases (C) is O₂/CO₂ movement in blood (e.g., Hb binding). Internal respiration (D) is gas exchange at tissue cells. In the alveoli, O₂ diffuses into blood (PaO₂ ≈100 mmHg) and CO₂ out (PaCO₂ ≈40 mmHg) across a 0.2-0.5 μm membrane, driven by partial pressure gradients (Fick's law). This distinguishes B from A's mechanics, C's circulation, or D's tissue focus external respiration's alveolar-capillary swap is the lung-specific process.