HESI A2 Anatomy and Physiology Practice Test

Correct Answer: C

Rationale: The correct answer is C: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen is taken in from the air into the bloodstream, and carbon dioxide is released from the bloodstream into the air in the alveoli. Trachea (A) is the windpipe that carries air to the lungs, bronchioles (B) are smaller airways that branch off from the bronchi, and larynx (D) is the voice box. These structures are important for breathing but not directly involved in gas exchange. Hence, the alveoli are the correct choice for gas exchange in the respiratory system.

Correct Answer: B

Rationale: The correct answer is B: Transverse. A transverse plane, also known as a horizontal plane, divides the body into upper (superior) and lower (inferior) portions. This plane would be used to separate the abdominal cavity from the thoracic cavity because it runs horizontally across the body at the level of the diaphragm, which separates these two cavities. The other choices are incorrect because: A: Sagittal plane divides the body into left and right portions. C: Frontal plane divides the body into front (anterior) and back (posterior) portions. D: Coronal plane is not a recognized anatomical term and is often used interchangeably with frontal plane.

Correct Answer: B

Rationale: The correct answer is B: Adrenal. The adrenal gland is located superior to the kidney in the human body. The adrenal glands are endocrine glands that sit on top of each kidney. They are responsible for producing hormones such as adrenaline and cortisol. The other choices (A: Pituitary, C: Hypothalamus, D: Pancreas) are not located superior to the kidney. The pituitary gland is located at the base of the brain, the hypothalamus is located above the pituitary gland, and the pancreas is located in the abdomen behind the stomach.

Correct Answer: B

Rationale: The correct answer is B, the urinary system. The kidneys play a crucial role in regulating electrolytes by filtering blood and excreting excess electrolytes into urine. This process helps maintain proper balance of electrolytes in the body. The endocrine system (A) primarily regulates hormones, not electrolytes. The lymphatic system (C) is responsible for immune function and fluid balance, not electrolyte regulation. The nervous system (D) controls communication between different parts of the body, but does not directly regulate electrolytes.

Correct Answer: A

Rationale: The correct answer is A: Hormones. Hormones are chemical messengers that are produced by endocrine glands and control growth, differentiation, and metabolism of specific target cells. They are released into the bloodstream and travel to target cells to elicit a response. Neurons (B) are nerve cells that transmit electrical signals, not chemical messengers. Glands (C) are structures that produce and secrete substances, including hormones, but they are not the chemical messengers themselves. Second messengers (D) are molecules involved in signal transduction pathways within cells, not the primary chemical messengers that control growth, differentiation, and metabolism.