Correct Answer: C

Rationale: The correct answer is C: He walked home in a cold rain. Walking in cold rain can lead to vasoconstriction, which impairs blood flow, increasing the likelihood of a sickle cell crisis in individuals with sickle cell disease. This can cause red blood cells to sickle and block blood vessels, leading to pain and tissue damage. Choices A, B, and D do not directly affect the physiology of sickle cell disease and are less likely to trigger a crisis.

Correct Answer: D

Rationale: Autoimmunity is when the immune system mistakenly attacks the body's own cells. Choice D is correct because it reflects this key feature - the inability to differentiate self from nonself. This leads to the immune system targeting healthy tissues. Choices A, B, and C are incorrect as they do not accurately describe autoimmunity. Choice A refers to endotoxins destroying B cells, which is not the definition of autoimmunity. Choice B mentions overproduction of reagin antibody, which is not related to autoimmunity. Choice C is incorrect as autoimmunity does not involve depression of the immune response but rather an inappropriate immune response.

Correct Answer: C

Rationale: The correct answer is C: 2, 3, and 4. High cholesterol, cigarette smoking, and a sedentary lifestyle are modifiable risk factors for developing hypertension. High cholesterol can lead to atherosclerosis, increasing blood pressure. Smoking can constrict blood vessels, raising blood pressure. Sedentary lifestyle can lead to obesity and overall poor cardiovascular health, contributing to hypertension. Race and age are non-modifiable risk factors. Choice A is incorrect because it includes race, a non-modifiable factor. Choice B is incorrect because it includes age, which is also non-modifiable. Choice D is incorrect because it includes all factors, including non-modifiable ones.

Correct Answer: A

Rationale: The correct answer is A because tachycardia (increased heart rate) and dilated pupils are classic responses of the sympathetic nervous system activation. Sympathetic nervous system is responsible for the fight or flight response, leading to increased heart rate and dilated pupils to prepare the body for quick action. Choice B is incorrect because hypoglycemia and headache are not specific to sympathetic nervous system function. Choice C is incorrect because increased peristalsis and abdominal cramping are more indicative of parasympathetic nervous system activity. Choice D is incorrect because pupil constriction and bronchoconstriction are actions of the parasympathetic nervous system, responsible for rest and digest functions.

Correct Answer: C

Rationale: The correct answer is C: To rule out cholinergic crisis Neostigmine. Edrophonium HCL is a short-acting cholinesterase inhibitor used to differentiate between myasthenic crisis and cholinergic crisis, as both conditions present similarly with muscle weakness. Administering edrophonium HCL will help determine if the patient's worsening weakness is due to excessive cholinergic stimulation from neostigmine (cholinergic crisis) or inadequate acetylcholine at the neuromuscular junction (myasthenic crisis). This step is crucial for proper management, as treating cholinergic crisis with more cholinesterase inhibitors like neostigmine can worsen symptoms. Incorrect choices: A: For its synergistic effect - Edrophonium HCL does not have a synergistic effect with neostigmine. B: Because of the client's resistance to - Resistance to neostigmine is not a reason to administer edrophonium H