Anatomy and Physiology Hesi A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: To break down food. The stomach plays a crucial role in digestion by using acid and enzymes to break down food into smaller particles for further processing in the intestines. Absorbing nutrients (A) primarily occurs in the small intestine, not the stomach. While the stomach does secrete digestive enzymes (C), its main function is not solely to secrete enzymes but to physically and chemically break down food. Storing glucose (D) is not a primary function of the stomach in digestion; glucose storage mainly occurs in the liver and muscles.

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: Nucleus. The nucleus contains the genetic material in the form of DNA, which carries the instructions for the cell's functions. The DNA is organized into chromosomes within the nucleus. Ribosomes (A) are involved in protein synthesis but do not contain genetic material. Mitochondria (C) have their own DNA but do not house the majority of the cell's genetic material. Endoplasmic reticulum (D) is involved in protein synthesis and lipid metabolism but does not contain genetic material. The nucleus is the control center of the cell, housing the genetic information essential for cell function and replication.

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: C

Rationale: The correct answer is C, skeletal muscle. Skeletal muscles are under voluntary control because they are attached to bones and allow conscious movement. The other choices are incorrect because smooth muscle (A) controls involuntary functions like digestion, cardiac muscle (B) controls the heart's contractions involuntarily, and striated muscle (D) is a general term that can refer to both cardiac and skeletal muscle, but skeletal muscle is the specific type under voluntary control.