HESI A2 Version 1 Anatomy and Physiology

Correct Answer: B

Rationale: The correct answer is B: axon. The axon is a long, slender projection of a neuron that conducts electrical impulses away from the neuron's cell body towards other neurons or target cells, such as muscles or glands, including towards a synapse. The cell body contains the nucleus and other organelles but does not carry action potentials. While a neuron is the overall structural and functional unit of the nervous system, the axon is specifically responsible for transmitting action potentials.

Correct Answer: B

Rationale: Aldosterone is a hormone produced by the adrenal glands that plays a key role in regulating sodium and potassium levels in the body. Its primary function is to conserve sodium by increasing its reabsorption in the kidneys, which helps maintain electrolyte balance and blood pressure. Therefore, the correct answer is B.

Correct Answer: B

Rationale: The correct answer is B, diffusion. Diffusion is the process by which oxygen moves from an area of high concentration (in the air) to an area of low concentration (in the blood) through the alveoli in the lungs. Osmosis involves the movement of water molecules across a semipermeable membrane, not oxygen molecules. Dissipation refers to the dispersal or scattering of something. Reverse osmosis is a process used in water purification, which is not relevant to the transport of oxygen in the lungs.

Correct Answer: B

Rationale: High-Density Lipoprotein (HDL) cholesterol is considered the healthiest type of cholesterol because it helps remove LDL cholesterol from the arteries, reducing the risk of heart disease. HDL acts as a scavenger, carrying cholesterol away from the arteries to the liver where it can be processed and eliminated from the body. Having high levels of HDL cholesterol is associated with a lower risk of cardiovascular diseases.