HESI A2 Anatomy and Physiology Practice Exam

Correct Answer: A

Rationale: Step-by-step rationale: 1. Selenium is an essential mineral known for its antioxidant properties. 2. Antioxidants help neutralize free radicals that can damage cells and lead to various health issues. 3. Selenium specifically plays a crucial role in protecting cells from oxidative stress. 4. Calcium, Sulfur, and Iron are important minerals for various bodily functions but are not primarily known for their antioxidant properties. In summary: - A: Selenium is correct due to its antioxidant properties. - B: Calcium is important for bone health, not specifically an antioxidant. - C: Sulfur is needed for protein synthesis, not primarily an antioxidant. - D: Iron is essential for oxygen transport, not primarily an antioxidant.

Correct Answer: C

Rationale: Trypsin is a digestive enzyme produced in the pancreas that specifically breaks down proteins into smaller peptides. It acts in the small intestine, targeting peptide bonds between amino acids. This process aids in protein digestion and absorption. Choices A, B, and D are incorrect as trypsin does not break down fats, starch, or nucleic acids in the body.

Correct Answer: A

Rationale: The correct answer is A: The endocrine system. The endocrine system produces hormones such as cortisol and adrenaline, which play a crucial role in the body's stress response. These hormones help regulate heart rate, metabolism, and other physiological responses to stress. The digestive system (B), lymphatic system (C), and respiratory system (D) do not have primary roles in controlling stress. The digestive system is responsible for breaking down food, the lymphatic system helps with immunity, and the respiratory system is involved in breathing.

Correct Answer: A

Rationale: The correct answer is A: Vitamin B1, which is another name for thiamine. Thiamine is essential for energy metabolism and nerve function. Vitamin B2 (choice B) is riboflavin, Vitamin B6 (choice C) is pyridoxine, and Vitamin D (choice D) is important for bone health. Thiamine deficiency can lead to serious conditions like beriberi, making it crucial for overall health.

Correct Answer: B

Rationale: The correct answer is B because the first step in pulmonary circulation is the pulmonary artery carrying deoxygenated blood from the heart to the lungs for oxygenation. This step initiates the process of oxygen exchange in the lungs. The other choices are incorrect as they do not represent the initial step in pulmonary circulation. Choice A occurs after oxygen exchange in the lungs, choice C describes the gas exchange process within the alveoli, and choice D refers to the systemic circulation, not the pulmonary circulation.