HESI A2 Anatomy and Physiology 2023

Correct Answer: B

Rationale: The correct answer is B: To produce bile and detoxify substances. The liver plays a crucial role in producing bile, which aids in digestion by breaking down fats. It also detoxifies harmful substances in the body. Choices A, C, and D are incorrect because the liver does not primarily filter blood, produce insulin, or produce red blood cells. Filtering blood is mainly done by the kidneys, insulin is produced by the pancreas, and red blood cells are produced in the bone marrow.

Correct Answer: B

Rationale: The correct answer is B: Thyroxine. Thyroxine, produced by the thyroid gland, plays a key role in regulating metabolism by controlling the body's metabolic rate. It influences how fast or slow our cells use energy. Insulin (A) regulates blood sugar levels, not metabolism. Glucagon (C) raises blood sugar levels. Cortisol (D) is a stress hormone that affects various body functions but is not primarily responsible for regulating metabolism. Thyroxine is crucial for maintaining overall metabolic balance in the body.

Correct Answer: C

Rationale: The correct answer is C: Medulla oblongata. The medulla oblongata is located in the brainstem and is responsible for regulating essential functions such as heart rate and breathing. It contains vital centers that control autonomic functions, including the cardiovascular and respiratory systems. The medulla receives inputs from various sensory receptors and sends signals to the heart and lungs to maintain homeostasis. The other choices are incorrect because: A: Cerebrum is primarily responsible for higher brain functions such as thinking and voluntary movements. B: Cerebellum is involved in coordination and balance, not in regulating heart rate and breathing. D: Hypothalamus plays a role in regulating body temperature, hunger, and thirst, but not specifically in controlling heart rate and breathing.

Correct Answer: A

Rationale: The correct answer is A: Cerebellum. The cerebellum is responsible for controlling balance and coordination by receiving sensory input from the inner ear and proprioceptive receptors in the muscles and joints. It processes this information to coordinate movements and maintain balance. The cerebrum (B) is primarily responsible for higher brain functions such as thinking and decision-making. The brainstem (C) controls basic life functions like breathing and heart rate. The medulla oblongata (D) is a part of the brainstem that regulates vital functions like blood pressure and breathing, not balance and coordination.

Correct Answer: B

Rationale: The ulnar nerve innervates the arm, specifically the pinky finger, ring finger, and part of the hand. Damage to the ulnar nerve will lead to decreased sensation in these areas. Therefore, the correct answer is B (Arm). The other choices are incorrect because the ulnar nerve does not supply sensation to the Leg (A), Face (C), or Abdomen (D).