HESI A2 Anatomy and Physiology 2023

Correct Answer: B

Rationale: The correct answer is B: Glomerulus. The glomerulus is a network of tiny blood vessels in the nephron that filters blood to form urine. It acts as the initial filtration site in the kidney, allowing waste products and excess substances to be removed from the blood. Bowman's capsule surrounds the glomerulus and collects the filtered fluid. The loop of Henle is responsible for reabsorbing water and electrolytes. While the nephron is the functional unit of the kidney, the glomerulus specifically performs the blood filtering process crucial for urine formation.

Correct Answer: B

Rationale: The correct answer is B: To produce bile and detoxify substances. The liver plays a crucial role in producing bile, which aids in digestion by breaking down fats. It also detoxifies harmful substances in the body. Choices A, C, and D are incorrect because the liver does not primarily filter blood, produce insulin, or produce red blood cells. Filtering blood is mainly done by the kidneys, insulin is produced by the pancreas, and red blood cells are produced in the bone marrow.

Correct Answer: A

Rationale: The correct answer is A: Biceps brachii. The biceps brachii is a muscle located in the upper arm that is responsible for flexing the forearm at the elbow joint. It is a powerful supinator of the forearm and also helps in shoulder flexion. The other choices are incorrect because: B: Triceps brachii is responsible for extending the forearm, not flexing it. C: Deltoid is a shoulder muscle responsible for abduction, not forearm flexion. D: Brachialis is a forearm muscle that assists in elbow flexion but is not the primary muscle involved in flexing the forearm.

Correct Answer: A

Rationale: The correct answer is A: Left ventricle. The left ventricle is the largest and strongest chamber of the heart because it is responsible for pumping oxygen-rich blood to the entire body. It has thicker muscle walls compared to other chambers to generate enough force to push blood through the body's systemic circulation. The left atrium receives oxygenated blood from the lungs, but it does not pump blood out of the heart. The right ventricle pumps blood to the lungs for oxygenation and is not as strong as the left ventricle. The right atrium receives deoxygenated blood from the body and sends it to the right ventricle. Therefore, the left ventricle is the correct answer due to its crucial role in systemic circulation and its muscular structure.

Correct Answer: A

Rationale: The pituitary gland regulates metabolism by producing and secreting hormones that control various bodily functions. It plays a key role in growth, reproduction, and overall hormone balance. This is supported by its location in the brain, connected to the hypothalamus which controls hormone production. Other choices are incorrect: Bile is produced in the liver, blood filtration is mainly done by the kidneys, and muscle movement is controlled by the nervous system.