Which one of the following statements BEST explains the relationship between inflammation of the heart (carditis) and infection with group A beta-hemolytic streptococci?

Correct Answer: A

Rationale: The correct answer is A: Streptococcal antigens induce antibodies cross-reactive with heart tissue. This is known as molecular mimicry, where antibodies produced against the streptococcal antigens also react with antigens present in heart tissue, leading to carditis. This mechanism is the basis for the development of rheumatic heart disease following a streptococcal infection. Choice B is incorrect because it does not explain the specific relationship between streptococcal infection and carditis. Choice C is incorrect as it describes a mechanism related to IgE and histamine release, which is not the primary mechanism involved in carditis. Choice D is incorrect as it focuses on neutrophils and proteases, which are not the primary mediators of carditis in the context of a streptococcal infection.

Correct Answer: B

Rationale: The correct answer is B because increasing the production of antigens by white blood cells during an allergic reaction is not a feedback mechanism maintaining homeostasis. Homeostasis involves maintaining internal stability despite external changes. A is correct because closing openings in leaves prevents water loss, maintaining plant hydration. C is correct because increased physical activity increases heart rate to maintain oxygen delivery. D is correct because the pancreas releases insulin to regulate blood sugar levels.

Correct Answer: C

Rationale: The correct answer is C because pouring running water over the lesions when urinating can help relieve discomfort and prevent irritation. This method helps to keep the affected area clean and reduces the risk of spreading the infection. Sitz baths (Option A) may provide temporary relief but should not be done daily. Applying ice packs (Option B) can worsen symptoms and using a hairdryer (Option D) may cause further irritation and delay healing. Running water is the most effective and gentle way to manage genital herpes symptoms.

Correct Answer: B

Rationale: Correct Answer: B Rationale: 1. Having the client wear a surgical mask helps contain respiratory droplets, reducing the risk of spreading TB. 2. Surgical masks protect others from inhaling infectious particles. 3. Airborne precautions are in place to prevent transmission through the air. 4. Wearing gloves or keeping the client in a negative pressure room does not address airborne transmission. Summary: Choice A is incorrect because the AP should not wear a gown during transport. Choice C is unnecessary as gloves do not prevent airborne transmission. Choice D is incorrect as it does not directly address containing respiratory droplets.

Correct Answer: B

Rationale: The correct answer is B because Raynaud's disease is characterized by reduced blood flow to extremities in response to cold or stress, leading to color changes, numbness, and tissue damage. Wearing layers of clothing helps maintain body heat and prevent cold-induced attacks, protecting against tissue damage. Walking and exercise are beneficial, but not in large intervals as it can trigger attacks. Increasing exposure to cold can worsen symptoms. Limiting fluid intake does not directly impact Raynaud's symptoms.