HESI A2 Anatomy and Physiology Practice Test 2023

Correct Answer: B

Rationale: The large intestine's main role is to absorb water and form solid waste. It reabsorbs water from the indigestible food residue, converting it into feces. Choice A is incorrect because nutrient absorption primarily occurs in the small intestine. Choice C is incorrect as fat breakdown occurs mainly in the small intestine. Choice D is incorrect because the large intestine does not secrete digestive enzymes as its main function is water absorption.

Correct Answer: B

Rationale: The correct answer is B: To pump blood throughout the body. The heart's primary function is to act as a muscular pump that circulates blood, delivering oxygen and nutrients to the body's tissues and removing waste products. It plays a crucial role in maintaining the flow of blood through the circulatory system. Explanation of other choices: A: To filter blood - This is incorrect, as the kidneys are responsible for filtering blood. C: To absorb oxygen - This is incorrect, as the lungs are responsible for absorbing oxygen. D: To remove carbon dioxide - This is incorrect, as the lungs are responsible for removing carbon dioxide during respiration.

Correct Answer: C

Rationale: The correct answer is C: Regulation of blood pressure. The adrenal glands produce hormones like adrenaline and aldosterone that help regulate blood pressure by controlling fluid balance and constriction/dilation of blood vessels. Adrenal glands do not directly regulate metabolism (choice A), produce bile (choice B), or produce insulin (choice D). Metabolism is mainly regulated by the thyroid gland, bile is produced in the liver, and insulin is produced in the pancreas. Hence, choices A, B, and D are incorrect in the context of the main function of the adrenal glands.

Correct Answer: C

Rationale: The correct answer is C: Regulating body temperature. The nervous system plays a vital role in maintaining homeostasis by controlling body temperature through signals to sweat glands and blood vessels. Choices A, B, and D are incorrect because transporting blood is primarily done by the circulatory system, protecting the body from infection is the role of the immune system, and digesting food is the function of the digestive system.

Correct Answer: B

Rationale: The correct answer is B: Insulin. The pancreas produces insulin to lower blood glucose levels by facilitating the uptake of glucose into cells for energy or storage. Glucagon (A) raises blood glucose levels, cortisol (C) is a stress hormone, and melatonin (D) regulates sleep cycles and has no direct impact on blood glucose levels. Insulin is the only hormone among the choices that specifically targets lowering blood glucose levels through its actions on glucose metabolism.