HESI A2 Anatomy and Physiology Quizlet

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: B

Rationale: The correct answer is B: Arteries. Arteries carry oxygenated blood away from the heart due to the contraction of the heart's left ventricle, which pumps blood to the rest of the body. Arteries have thick, muscular walls to withstand the high pressure generated by the heart. Veins (A) carry deoxygenated blood back to the heart, capillaries (C) facilitate exchange of gases and nutrients, and lymphatic vessels (D) transport lymph fluid, not blood.

Correct Answer: A

Rationale: The correct answer is A: Adrenal gland. The adrenal glands are located on top of the kidneys and are responsible for producing hormones like adrenaline and cortisol. The other choices, B: Thyroid gland, C: Pineal gland, and D: Pancreas, are not located on top of the kidneys and do not have a direct anatomical connection to the kidneys. The adrenal gland's location and its function in hormone production make it the correct choice for this question.

Correct Answer: C

Rationale: The correct answer is C: Mitochondria. Mitochondria are responsible for generating energy in the form of ATP through cellular respiration. This organelle contains enzymes needed for the process of oxidative phosphorylation. The other choices, A: Nucleus, B: Ribosome, and D: Golgi apparatus, do not directly participate in energy production. The nucleus houses genetic material, ribosomes are involved in protein synthesis, and the Golgi apparatus is responsible for processing and packaging proteins.

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.