Final Exam Pathophysiology

Correct Answer: A

Rationale: The correct answer is A: Diarrhea. Hepatotoxicity caused by isoniazid can present with various symptoms, including yellow discoloration of the sclera of the eyes, which indicates jaundice. Another common sign of hepatotoxicity is gastrointestinal symptoms such as nausea, vomiting, and diarrhea, which can occur due to liver dysfunction affecting bile production and digestion. Numbness (choice B) is more commonly associated with peripheral neuropathy caused by isoniazid, while diminished vision (choice C) and light-colored stools (choice D) are not typical manifestations of hepatotoxicity.

Correct Answer: A

Rationale: The correct answer is changes in cell shape, size, and organization (Choice A). Pap smears are performed to detect potential precancerous or cancerous conditions by examining the cells for any abnormalities in their shape, size, or organization. This helps in identifying early signs of cervical cancer. Choices B, C, and D are incorrect because Pap smears primarily focus on detecting cellular changes associated with cancer, not unexpected cell types, ischemic changes, or abnormally high numbers of cells.

Correct Answer: C

Rationale: In this scenario, a decubitus ulcer on the coccyx indicates a breakdown of the skin's integrity due to prolonged pressure. The skin is the primary defense mechanism of the body against external pathogens. When the skin is compromised, it can lead to infections and other complications. The mucous membrane (Choice A) plays a role in protecting internal surfaces, not the skin. The respiratory tract (Choice B) is involved in breathing and not directly related to the skin's defense. The gastrointestinal tract (Choice D) is responsible for digestion and absorption of nutrients, not the primary defense mechanism against external threats like the skin.

Correct Answer: C

Rationale: IgM is the first immunoglobulin to challenge the antigen during an immune response. IgM is the primary antibody produced during the initial or primary immune response. It is efficient in agglutination and complement activation, making it crucial in the early stages of defense. IgA is mainly found in mucosal areas and secretions. IgG is the most abundant antibody in circulation and is involved in secondary immune responses. IgE is primarily associated with allergic reactions and parasitic infections. Therefore, IgM is the correct choice as it acts first during the immune response, while the other immunoglobulins have different roles and functions.

Correct Answer: C

Rationale: The correct answer is C: IgE. A severe allergic reaction, such as the one experienced by the 10-year-old male after being stung by a bee, is mediated by IgE. IgE is involved in common allergic responses, triggering the release of histamine and other chemicals that lead to allergy symptoms. Choice A, Toxoids, are inactivated toxins used in vaccines. Choice B, IgA, is mainly found in mucosal areas and secretions, playing a role in mucosal immunity. Choice D, IgM, is the first antibody produced in response to an infection.