1. A patient presents with decreased bone density and frequent fractures. Which hormone should be primarily assessed for potential imbalance? - A) Calcitonin - B) Parathyroid hormone - C) Thyroxine - D) Cortisol Answer: B) Parathyroid hormone. Rationale: Parathyroid hormone regulates calcium levels in the blood, and an imbalance can lead to bone density issues. 2. During a lab dissection, a student observes that the muscle fibers in the heart are branched and interconnected. This structural feature contributes to the heart's ability to: - A) Contract unidirectionally. - B) Pump blood at high pressures. - C) Conduct electrical impulses rapidly. - D) Regenerate after injury. Answer: C) Conduct electrical impulses rapidly. Rationale: The interconnection of cardiac muscle fibers allows for synchronized contractions due to rapid impulse conduction. 3. A 65-year-old male with a history of smoking is diagnosed with emphysema. Which physiological process is primarily affected by this condition? - A) Gas exchange in the alveoli - B) Mucus production in the bronchi - C) Blood flow through the pulmonary artery - D) Oxygen transport in red blood cells Answer: A) Gas exchange in the alveoli. Rationale: Emphysema damages the alveoli, reducing the surface area for gas exchange. 4. In a patient experiencing hypovolemic shock, which compensatory mechanism initially occurs to maintain blood pressure? - A) Vasodilation of arterioles - B) Decreased heart rate - C) Vasoconstriction of arterioles - D) Reduced cardiac output