HESI A2 Anatomy and Physiology Practice Exam

Correct Answer: D

Rationale: The correct answer is D: Cilia. Cilia are part of the body's primary defense system in the respiratory tract, not the secondary defense system. The secondary defense system involves immune cells like macrophages, leukocytes, and T cells that work to target and eliminate pathogens. Cilia primarily function to trap and remove foreign particles in the airways as part of the body's physical barrier against infections. Therefore, cilia are not considered part of the secondary defense system, making choice D the correct answer.

Correct Answer: B

Rationale: The correct answer is B because skeletal muscle attaches to bones by tendons, allowing for movement of the body. Tendons are tough connective tissues that anchor muscles to bones. This attachment enables the contraction of skeletal muscles to produce movement at the joints. Choices A, C, and D are incorrect. Skeletal muscle typically makes up around 40-50% of the body's weight, muscle contraction plays a role in temperature regulation through shivering, and skeletal muscles can contract even at rest due to maintaining posture or supporting the body.

Correct Answer: B

Rationale: The correct answer is B: nervous system. The retinas belong to the nervous system as they are part of the sensory organs responsible for receiving and processing visual information. The retinas contain photoreceptor cells that convert light into electrical signals, which are then transmitted to the brain via the optic nerve for interpretation. The skeletal system (A) is responsible for providing support and protection for the body, the lymphatic system (C) is responsible for immune function and fluid balance, and the circulatory system (D) is responsible for transporting blood and nutrients throughout the body. Therefore, the retinas do not belong to these systems.

Correct Answer: A

Rationale: The correct answer is A because the gallbladder is located in the upper right quadrant of the abdomen. When a gallstone blocks the bile duct, it can cause pain in this area due to the distension and inflammation of the gallbladder. Choices B, C, and D are incorrect because gallstone pain is typically felt in the upper right quadrant where the gallbladder is located, not in the lower right quadrant, umbilical region, or along the pelvic girdle.

Correct Answer: A

Rationale: The correct answer is A: When they block a duct. Gallstones cause issues when they obstruct the flow of bile from the gallbladder through the bile ducts. This blockage can lead to severe pain, inflammation, infection, and potentially life-threatening complications. Choices B and C focus on the composition of gallstones, which may not always correlate with symptom severity. Choice D is incorrect because gallstones dissolving can actually relieve symptoms rather than cause problems.