HESI A2 Anatomy and Physiology Practice Test 2023

Correct Answer: B

Rationale: The correct answer is B: To fight infections. White blood cells are a crucial part of the immune system, responsible for detecting and destroying pathogens like bacteria, viruses, and other harmful substances. They play a vital role in protecting the body against infections and diseases. Choice A is incorrect because red blood cells, not white blood cells, carry oxygen. Choice C is incorrect as white blood cells do not primarily transport nutrients; that is the role of the circulatory system. Choice D is incorrect because clotting of blood is mainly carried out by platelets and certain proteins, not white blood cells.

Correct Answer: B

Rationale: The correct answer is B: To absorb water. The primary role of the large intestine is to absorb water from the undigested food material that passes through it. This ensures that the body maintains proper hydration and regulates the consistency of stool. The other choices are incorrect because: A: The small intestine is primarily responsible for absorbing nutrients, not the large intestine. C: The breakdown of food mainly occurs in the stomach and small intestine, not the large intestine. D: Digestive enzymes are primarily secreted by the pancreas and small intestine, not the large intestine.

Correct Answer: B

Rationale: The small intestine's primary function is to absorb nutrients from digested food. It is lined with millions of tiny villi that increase its surface area for absorption. Digestive enzymes are produced by the pancreas and released into the small intestine, so A is incorrect. Breaking down food primarily occurs in the stomach, making C incorrect. Absorbing water mainly occurs in the large intestine, so D is incorrect. Therefore, the correct answer is B as the small intestine is where the majority of nutrient absorption takes place.

Correct Answer: B

Rationale: The correct answer is B: Adrenal gland. The adrenal gland is responsible for producing adrenaline, also known as epinephrine, in response to stress or danger. This hormone helps the body respond to fight-or-flight situations by increasing heart rate, blood flow to muscles, and boosting energy levels. A: Thyroid gland produces hormones that regulate metabolism, not adrenaline. C: Pituitary gland releases various hormones but not adrenaline. D: Pineal gland produces melatonin, a hormone that regulates sleep-wake cycles, not adrenaline. In summary, the adrenal gland is the correct answer because it specifically produces adrenaline in response to stress, while the other glands mentioned have different functions and do not produce adrenaline.

Correct Answer: C

Rationale: The correct answer is C: Kidneys. The kidneys are responsible for filtering and cleaning the blood through the process of removing waste products, excess fluids, and toxins, which are then excreted as urine. The kidneys play a crucial role in maintaining the body's overall balance of fluids and electrolytes. The other choices are incorrect because: A: Lungs are responsible for exchanging gases, not filtering blood. B: Heart is a muscular organ that pumps blood, not involved in blood filtration. D: Liver plays a role in detoxification and metabolism, but it does not directly filter blood like the kidneys do.