HESI A2 Anatomy and Physiology Quizlet

Correct Answer: B

Rationale: The correct answer is B: Lens. The lens is responsible for focusing light onto the retina by adjusting its shape to bend the light rays. The cornea (A) primarily helps in refracting light, while the pupil (C) and iris (D) are involved in regulating the amount of light entering the eye, not in focusing light onto the retina. Therefore, the lens is the correct choice as it plays a crucial role in the process of focusing light onto the retina.

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: A

Rationale: The correct answer is A: Parathyroid gland. During stress, the hypothalamus signals the pituitary gland to release ACTH, which then stimulates the adrenal cortex to release stress hormones like cortisol. The posterior pituitary releases oxytocin and vasopressin, not directly related to stress. The parathyroid gland regulates calcium levels, not involved in the stress response.

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.

Correct Answer: C

Rationale: The correct answer is C: Amygdala. The amygdala is a key structure in the brain responsible for processing emotions and forming emotional memories. It plays a crucial role in fear responses, emotional regulation, and memory consolidation. The other choices are incorrect because: A: Cerebrum is responsible for higher brain functions such as thinking, decision-making, and voluntary movements. B: Cerebellum is primarily involved in motor coordination and balance. D: Brainstem controls basic functions like breathing, heart rate, and consciousness levels.