HESI A2 Anatomy and Physiology Quizlet

Correct Answer: A

Rationale: The main function of the circulatory system is to transport oxygen and nutrients to all cells in the body. This is achieved through the blood vessels and the pumping action of the heart. Oxygen is necessary for cellular respiration, while nutrients are essential for cell growth and metabolism. Without these, cells cannot function properly, leading to organ failure and ultimately, death. Options B, C, and D are incorrect because although the circulatory system indirectly helps remove waste products, regulate body temperature, and protect organs, these are not its primary functions.

Correct Answer: B

Rationale: The correct answer is B: Pituitary gland. The pituitary gland is known as the 'master gland' because it controls the functions of other endocrine glands in the body. It secretes hormones that regulate various bodily functions, such as growth, metabolism, and reproduction. Other choices are incorrect because the thyroid gland mainly regulates metabolism, the adrenal gland is responsible for stress response and metabolism, and the pineal gland produces melatonin to regulate sleep-wake cycles. The pituitary gland stands out as the 'master gland' due to its control over other gland functions.

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.

Correct Answer: D

Rationale: The correct answer is D, the left ventricle. The left ventricle is the strongest and largest chamber of the heart because it is responsible for pumping oxygenated blood to the entire body, requiring more muscle mass and power. It has thicker walls compared to the other chambers, enabling it to generate higher pressure to propel blood throughout the systemic circulation. The other choices, A, B, and C, are incorrect as the atria (left and right) are smaller chambers that primarily receive blood from the body and lungs, respectively. The right ventricle pumps deoxygenated blood to the lungs, but it is not as strong or as large as the left ventricle due to the shorter distance it needs to pump blood.

Correct Answer: D

Rationale: The correct answer is D: Hypothalamus. The hypothalamus is responsible for releasing thyrotrophic-releasing hormone, growth hormone-releasing hormone, and gonadotropin-releasing hormone. The hypothalamus regulates the release of hormones from the pituitary gland, making it a crucial part of the endocrine system. The thymus (A) is involved in immune function, the pituitary gland (B) releases hormones but does not release these specific hormones, and the pineal gland (C) primarily secretes melatonin and regulates sleep-wake cycles, not the hormones mentioned in the question.