Anatomy HESI A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: To store urine. The urinary bladder serves as a reservoir for storing urine before it is eliminated from the body. It collects and holds urine until a person is ready to excrete it. The other choices are incorrect because: A) The kidneys filter waste from the blood, not the bladder. C) Fluid balance is primarily regulated by the kidneys and hormones, not the bladder. D) Waste removal from the body is mainly carried out by the kidneys and excretory system, not the bladder.

Correct Answer: C

Rationale: Platelets play a crucial role in blood clotting, known as hemostasis. Step 1: When a blood vessel is damaged, platelets adhere to the site to form a temporary plug. Step 2: Platelets release chemicals that attract more platelets and help in clot formation. Step 3: This clotting process prevents excessive bleeding. Choice A is incorrect as oxygen is primarily carried by red blood cells. Choice B is incorrect as fighting infections is mainly done by white blood cells. Choice D is incorrect as nutrient transport is mainly carried out by the plasma in the blood.

Correct Answer: B

Rationale: The primary function of the alveoli in the lungs is to exchange oxygen and carbon dioxide. This process occurs through diffusion, where oxygen moves from the alveoli into the bloodstream, and carbon dioxide moves from the bloodstream into the alveoli to be exhaled. This exchange is essential for oxygenating the blood and removing carbon dioxide, maintaining proper gas exchange in the body. Why the other choices are incorrect: A: Alveoli do play a role in removing carbon dioxide, but their primary function is the exchange of oxygen and carbon dioxide. C: While alveoli do transport oxygen to the bloodstream, they also exchange carbon dioxide, making this choice incomplete. D: Alveoli do not filter blood; their main function is gas exchange in the lungs.

Correct Answer: A

Rationale: The correct answer is A: To filter blood and remove old red blood cells. The spleen is an important organ in the lymphatic system responsible for filtering blood, removing old or damaged red blood cells, and storing platelets. It also plays a role in immune function by producing antibodies and storing lymphocytes. Choices B, C, and D are incorrect as the spleen's main functions are related to blood filtration and immune response, not lymphocyte production, vitamin storage, or temperature regulation.

Correct Answer: C

Rationale: The liver's role in detoxification involves converting toxins into less harmful substances through various biochemical processes, such as oxidation, reduction, and conjugation. This helps in eliminating harmful substances from the body. Bile secretion (A) aids in digestion, glucose storage (B) is related to energy regulation, and insulin production (D) is mainly carried out by the pancreas. Therefore, choice C is correct as it specifically addresses the liver's detoxification function.