Anatomy HESI A2

Correct Answer: C

Rationale: The correct answer is C: The lymphatic system. This system includes lymph nodes, spleen, thymus, and bone marrow, which are responsible for producing and circulating antibodies. Lymphocytes, a type of white blood cell found in the lymphatic system, are key in generating antibodies to fight infections. The endocrine system (A) regulates hormones, the digestive system (B) processes food, and the nervous system (D) controls communication in the body, none of which are directly involved in antibody production.

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: B

Rationale: The correct answer is B because a headrest in a car prevents traumatic injury by limiting hyperextension of the neck during a rear-end collision. When a car is hit from behind, the headrest supports the head and prevents the neck from snapping backward, which can cause whiplash or other neck injuries. Choices A, C, and D are incorrect because the primary purpose of the headrest is to limit hyperextension of the neck, not hyperflexion, vertebral compression, or disc degeneration.

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: B

Rationale: The correct answer is B: In the nervous system. Schwann cells are a type of glial cell that provide support and insulation to nerve cells in the nervous system. They form the myelin sheath around axons, which helps in the transmission of nerve impulses. Schwann cells are not found in the digestive system (A), skeletal system (C), or muscular system (D) as they are specifically related to the nervous system. This distinction makes option B the correct choice.