Anatomy HESI A2

Correct Answer: C

Rationale: The correct answer is C because body cells recognizing a pathogen represent an adaptive immune response, which is a specific and targeted defense mechanism. In contrast, choices A, B, and D are all examples of innate immune defenses that provide a nonspecific barrier against pathogens without the need for prior exposure. A: A low pH in the stomach creates an acidic environment that can kill many pathogens. B: Cilia in the trachea help to trap and remove inhaled pathogens. D: Mucus in the nasal cavity acts as a physical barrier to trap and remove pathogens. Therefore, choice C stands out as it involves a more sophisticated and specific defense mechanism compared to the other choices.

Correct Answer: C

Rationale: The correct answer is C: Parathyroid. The parathyroid gland controls Calciferol (Vitamin D) levels in the body by regulating calcium and phosphorus metabolism. The thyroid gland (choice A) regulates metabolism but not specifically Calciferol. The pituitary gland (choice B) controls various hormones but not Calciferol. The hypothalamus (choice D) regulates the release of hormones from the pituitary gland but does not directly control Calciferol. Therefore, the parathyroid gland is the correct choice for controlling Calciferol levels in the body.

Correct Answer: A

Rationale: The correct answer is A: To break down proteins. Pepsin is an enzyme produced in the stomach that specifically functions to break down proteins into smaller peptides. This process is crucial for the digestion and absorption of proteins in the body. Pepsin works optimally in the acidic environment of the stomach. Choices B, C, and D are incorrect because pepsin is not involved in breaking down starches, emulsifying fats and oils, or absorbing water and nutrients. Other enzymes like amylase are responsible for breaking down starches, bile helps emulsify fats, and various enzymes and mechanisms are involved in water and nutrient absorption in the digestive system.

Correct Answer: D

Rationale: The correct answer is D: lateral. Cheekbones are positioned to the side of the nose, making them lateral to the nose. This is based on anatomical terminology where lateral refers to the side of the body or part away from the midline. Choice A (anterior) is incorrect as it refers to the front of the body, not the side where the cheekbones are located. Choice B (proximal) is incorrect as it indicates a position closer to the point of attachment or center of the body, not the side where the cheekbones are. Choice C (deep) is incorrect as it refers to a position beneath the surface, not the side positioning of the cheekbones relative to the nose.

Correct Answer: C

Rationale: The correct answer is C because body cells recognizing a pathogen represent an adaptive immune response, which is a specific and targeted defense mechanism. In contrast, choices A, B, and D are all examples of innate immune defenses that provide a nonspecific barrier against pathogens without the need for prior exposure. A: A low pH in the stomach creates an acidic environment that can kill many pathogens. B: Cilia in the trachea help to trap and remove inhaled pathogens. D: Mucus in the nasal cavity acts as a physical barrier to trap and remove pathogens. Therefore, choice C stands out as it involves a more sophisticated and specific defense mechanism compared to the other choices.