HESI A2 Anatomy and Physiology Practice Exam - Nurselytic

Correct Answer: C

Rationale: The correct answer is C: Humerus and scapula. The rotator cuff is a group of muscles and tendons that help stabilize the shoulder joint. Specifically, the rotator cuff muscles help to stabilize the head of the humerus (the upper arm bone) within the shallow socket of the scapula (shoulder blade). This stabilizing action is crucial for maintaining shoulder joint function and preventing injuries.

Choices A, B, and D are incorrect because the rotator cuff primarily stabilizes the humerus and scapula, not the radius, ulna, or clavicle.

Correct Answer: D

Rationale: Melatonin is the hormone produced by the pineal gland. It plays a crucial role in regulating the sleep-wake cycle and is instrumental in maintaining the body's circadian rhythm. Melatonin production is triggered by darkness and inhibited by light, aiding in signaling the body when it is time to sleep. Corticosteroid, oxytocin, and prolactin are hormones produced by other glands in the body and are not associated with the pineal gland.
Therefore, they are incorrect choices for this question.

Correct Answer: D

Rationale: The correct answer is the Achilles tendon. The Achilles tendon is a strong tendon located at the back of the human leg, connecting the calf muscles to the heel bone. This positioning makes it a posterior feature, situated at the rear of the leg. The patella, also known as the kneecap, is positioned at the front of the leg, making it an anterior feature. The quadriceps sartorius are muscles located in the front of the thigh, not at the back of the leg. Additionally, the triceps brachii is a muscle found in the upper arm, not in the leg, making it an incorrect choice.

Correct Answer: C

Rationale: Trypsin is an enzyme that specifically breaks down proteins into smaller peptides by hydrolyzing peptide bonds. It is a key enzyme involved in the digestion of proteins in the body, particularly in the small intestine where it helps in the final stages of protein digestion.

Choices A, B, and D are incorrect because trypsin does not break down fats, starch, or nucleic acids; its primary function is the digestion of proteins.

Correct Answer: A

Rationale: A gallstone is most likely to cause pain in the upper right quadrant of the abdomen. This specific area corresponds to the location of the gallbladder. When a gallstone blocks the flow of bile from the gallbladder, it can lead to inflammation and pain in this region. The pain may also radiate to the back or right shoulder blade due to referred pain patterns associated with gallbladder issues.

Choices B, C, and D are incorrect because gallstone pain is typically felt in the upper right quadrant of the abdomen, not the lower right quadrant, umbilical region, or along the pelvic girdle.