ATI Pathophysiology Final Exam

Correct Answer: C

Rationale: Humoral immunity is mediated by B cells, not natural killer cells, T cells, or neutrophils. B cells are responsible for producing antibodies, which are essential components of humoral immunity.

Correct Answer: A

Rationale: The correct answer is A: Levonorgestrel (Plan B). Levonorgestrel is the most commonly prescribed medication for emergency contraception within 72 hours of unprotected intercourse. It is effective when taken within 72 hours after intercourse, with better efficacy the sooner it is taken. Choice B, Mifepristone (RU-486), is not indicated for emergency contraception but is used for medical abortion. Choice C, Ulipristal acetate (ella), is another option for emergency contraception that is effective up to 120 hours after unprotected intercourse. Choice D, Estradiol (Estrace), is not used for emergency contraception.

Correct Answer: D

Rationale: The direct effects of antibodies include neutralization, agglutination, and precipitation. Antibodies neutralize pathogens by binding to them and preventing their harmful effects. Agglutination involves the clumping together of pathogens, making it easier for phagocytes to engulf them. Precipitation refers to the process where antibodies bind to soluble antigens, forming large complexes that are easily removed from the body. Phagocytosis, on the other hand, is an indirect effect of antibodies where phagocytes engulf and destroy pathogens opsonized by antibodies, not a direct effect.

Correct Answer: A

Rationale: When a patient taking an oral contraceptive misses one pill, the correct action is to take two pills as soon as they remember and then continue the regular schedule. Option A is the correct answer because doubling up the dose helps maintain the effectiveness of the contraceptive. Option B is incorrect because taking only one pill after missing one may decrease contraceptive effectiveness. Option C is wrong as skipping the missed pill can also reduce effectiveness. Option D is inaccurate because taking two pills immediately is not necessary; the patient should take the missed pill as soon as remembered and then resume the regular dosing schedule.

Correct Answer: D

Rationale: A rash from poison ivy is an example of a type IV hypersensitivity reaction. Type IV hypersensitivity reactions are delayed cell-mediated immune responses involving T cells. This type of reaction is characterized by a delayed onset, typically occurring 48-72 hours after exposure to the antigen. Choice A, Type I hypersensitivity reactions, are immediate hypersensitivity reactions mediated by IgE antibodies. Choices B and C, Type II and Type III hypersensitivity reactions, involve antibody-mediated cytotoxicity and immune complex deposition, respectively, which are not characteristic of poison ivy-induced rashes.