HESI A2 Anatomy and Physiology Quizlet

Correct Answer: B

Rationale: The correct answer is B: Arteries. Arteries carry oxygenated blood away from the heart to various parts of the body. They have thick, muscular walls to withstand the high pressure from the heart's pumping action. Veins (A) carry blood back to the heart, capillaries (C) facilitate exchange of nutrients and waste, and nerves (D) transmit signals but do not transport blood.

Correct Answer: B

Rationale: The correct answer is B: Quadriceps. The quadriceps muscle group, specifically the rectus femoris, is primarily responsible for extending the knee. This muscle group is located on the front of the thigh and contracts to straighten the knee joint. The other choices are incorrect because: A: Hamstrings primarily flex the knee. C: Calves primarily assist in ankle plantar flexion. D: Glutes primarily extend the hip, not the knee.

Correct Answer: C

Rationale: The correct answer is C: Medulla oblongata. The medulla oblongata is located in the brainstem and is responsible for controlling vital functions such as breathing, heart rate, and blood pressure. It contains important centers that regulate these involuntary actions, making it the correct choice. The cerebrum (A) is responsible for higher brain functions such as thinking and voluntary movement. The cerebellum (B) is involved in coordination and balance. The hypothalamus (D) regulates body temperature, hunger, and thirst, but does not directly control breathing and heart rate.

Correct Answer: C

Rationale: The correct answer is C: Pineal gland. The pineal gland secretes melatonin, a hormone responsible for regulating sleep-wake cycles. It receives signals from the retina about light levels, which helps to synchronize the body's internal clock. The hypothalamus (A) regulates various bodily functions but is not specifically responsible for sleep-wake cycles. The thalamus (B) is involved in relaying sensory information but not directly related to sleep regulation. The cerebellum (D) is primarily involved in motor control and coordination, not sleep regulation. Therefore, the pineal gland is the structure in the brain that directly regulates sleep and wakefulness.

Correct Answer: A

Rationale: The correct answer is A: Hippocampus. The hippocampus is involved in memory formation as it plays a crucial role in the consolidation of short-term memory into long-term memory. It also helps in spatial navigation and declarative memory. The amygdala (choice B) is associated with emotions and emotional memories, not memory formation. The cerebellum (choice C) is primarily responsible for motor coordination, not memory. The medulla oblongata (choice D) is involved in vital autonomic functions like breathing and heart rate, not memory.