Anatomy HESI A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: Adrenal cortex. During stress, the adrenal cortex secretes cortisol and aldosterone, which help the body respond to stress. The parathyroid gland (A) regulates calcium levels, not stress hormones. The posterior pituitary gland (C) releases hormones like oxytocin and vasopressin, not stress hormones. The hypothalamus (D) plays a role in regulating the stress response by signaling the adrenal cortex to release stress hormones.

Correct Answer: A

Rationale: The primary function of the cardiovascular system is to pump blood throughout the body. This process ensures oxygen and nutrients are delivered to tissues and organs, while also removing waste products. Choice A is correct as it directly relates to the main role of the cardiovascular system. Choices B, C, and D are incorrect because although the cardiovascular system indirectly contributes to delivering nutrients, regulating body temperature, and protecting against infection through immune responses, these are not its primary functions.

Correct Answer: B

Rationale: The correct answer is B: Lens. The lens of the eye is responsible for focusing light onto the retina by changing its shape to adjust the focal length. The cornea (A) helps in the initial focusing of light but does not have the ability to adjust focus. The retina (C) is the layer of cells at the back of the eye where light is converted into electrical signals, not responsible for focusing light. The pupil (D) controls the amount of light entering the eye but does not focus light onto the retina.

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: 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.