Anatomy and Physiology Hesi A2 Practice Test

Correct Answer: C

Rationale: The motor cortex is located in the front portion of the parietal lobe. This area is specifically known as the primary motor cortex, which is responsible for planning, controlling, and executing voluntary movements. It sends signals to the muscles to initiate movement. Option A (back of the head) is incorrect as that area is primarily related to visual processing. Option B (top middle portion of the parietal lobe) is incorrect as that area is more associated with somatosensory processing. Option D (around the auditory cortex) is incorrect as the auditory cortex is responsible for processing auditory information, not motor functions.

Correct Answer: D

Rationale: Step-by-step rationale for why choice D (Parathyroid) is correct: 1. Parathyroid glands are not directly involved in the stress response. 2. When under stress, hypothalamus triggers the release of hormones from posterior pituitary and adrenal cortex. 3. Parathyroid regulates calcium levels, not stress hormones. 4. Choices A, B, and C are all directly involved in the stress response. In summary, the parathyroid gland is not a part of the stress response system, unlike the posterior pituitary, hypothalamus, and adrenal cortex.

Correct Answer: B

Rationale: The correct answer is B: epidermis. The epidermis is the outermost layer of the skin, serving as a protective barrier. It consists of several layers of cells, including keratinocytes which provide waterproofing and protection. The dermis (choice A) is the layer beneath the epidermis, providing structural support. Subcutaneous tissue (choice C) and hypodermis (choice D) are the deepest layers of the skin, mainly composed of fat cells and connective tissue, playing a role in insulation and cushioning. Therefore, the epidermis is the correct choice as it directly interacts with the external environment and is responsible for protecting the body.

Correct Answer: B

Rationale: The correct answer is B: To detoxify harmful substances. The liver plays a crucial role in metabolism by detoxifying harmful substances such as drugs and alcohol. It metabolizes these substances into less harmful compounds for elimination from the body. Other choices are incorrect because: A: The liver produces bile to aid in digestion, not directly related to metabolism. C: While the liver stores glucose in the form of glycogen, it is not its primary role in metabolism. D: Insulin is produced by the pancreas, not the liver, to regulate blood sugar levels, not directly related to liver's role in metabolism.

Correct Answer: B

Rationale: The correct answer is B: Left ventricle. The left ventricle is the largest and strongest chamber of the heart because it is responsible for pumping oxygenated blood to the entire body. It has thick muscular walls to generate enough force to propel blood through the systemic circulation. The right atrium (choice A) receives deoxygenated blood from the body, the right ventricle (choice C) pumps this blood to the lungs for oxygenation, and the left atrium (choice D) receives oxygenated blood from the lungs. None of these chambers have the same pumping workload and muscular thickness as the left ventricle, making it the correct answer.