Anatomy HESI A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: Vitamin D. Vitamin D is essential for bone health as it helps the body absorb calcium, a crucial mineral for bone strength. Without sufficient Vitamin D, the body cannot utilize calcium efficiently, leading to weakened bones. Explanation of incorrect choices: A: Vitamin A is important for vision and immune function, but it is not directly related to bone health. C: Vitamin C is vital for collagen production and immune function, but it does not play a direct role in bone health. D: Vitamin K is necessary for blood clotting and bone mineralization, but Vitamin D is more critical for calcium absorption, making it the better choice for bone health.

Correct Answer: B

Rationale: The correct answer is B: Larynx. The larynx is an organ of the respiratory system responsible for producing sound and protecting the trachea during swallowing. It is located in the throat region and contains vocal cords. The brain (A) is part of the nervous system, not the respiratory system. The urethra (C) is part of the urinary system, and the pancreas (D) is part of the digestive system. Therefore, the larynx is the only choice directly related to the respiratory system.

Correct Answer: C

Rationale: The primary function of hemoglobin in red blood cells is to carry oxygen. Hemoglobin binds to oxygen in the lungs and releases it to tissues throughout the body. This process is essential for cellular respiration. Choice A is incorrect because hemoglobin does not transport nutrients. Choice B is incorrect because the function of fighting infections is carried out by the immune system, not hemoglobin. Choice D is incorrect because hemoglobin does not produce energy; it facilitates the transport of oxygen which is necessary for energy production in cells.

Correct Answer: D

Rationale: The correct answer is D: epiglottis. The epiglottis is a flap of cartilage located at the base of the tongue, which moves to cover the entrance of the trachea during swallowing, preventing food from entering the airway and directing it to the esophagus. The trachea (A) is the windpipe that leads to the lungs, not involved in preventing food entry. The esophagus (B) is the tube that carries food to the stomach, not responsible for blocking food from entering the airway. The diaphragm (C) is a muscle that aids in breathing by contracting and relaxing to allow for lung expansion, not related to preventing food aspiration.

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.