Correct Answer: A

Rationale: The correct answer is A: Nystagmus. A phenytoin blood level of 35 mcg/ml is above the therapeutic range (usually 10-20 mcg/ml). Excessive levels can lead to symptoms such as nystagmus, which is an involuntary eye movement commonly seen with phenytoin toxicity. Nystagmus is a known side effect of phenytoin overdose. Choices B and C are incorrect because a level of 35 mcg/ml is not within the normal therapeutic range, so symptoms would be expected. Choice D, Slurred speech, is not typically associated with phenytoin toxicity.

Correct Answer: C

Rationale: The correct answer is C: Axon. The axon is the part of the neuron that transmits impulses away from the cell body towards other neurons, muscles, or glands. Its structure allows for the rapid transmission of electrical signals. Rationale: 1. Dendrites receive signals and transmit them towards the cell body, so A is incorrect. 2. Neurolemma is the outermost layer of a Schwann cell, not a part of the neuron responsible for transmitting impulses, so B is incorrect. 3. The synapse is the junction between two neurons where communication occurs, not a part of the neuron transmitting impulses, so D is incorrect.

Correct Answer: B

Rationale: The correct answer is B (4 hours) because parenteral ampicillin should be administered within 1 hour of mixing. This is crucial to ensure efficacy and prevent bacterial growth in the solution. Choice A (1 hour) is incorrect because it does not allow enough time for administration after mixing. Choice C (2 hours) is also incorrect as it exceeds the recommended time limit. Choice D (8 hours) is incorrect as it exceeds the safe window for administration post-mixing, increasing the risk of bacterial contamination and reduced effectiveness. Thus, the optimal timeframe for administering parenteral ampicillin after mixing is within 4 hours to maintain its therapeutic benefits.

Correct Answer: B

Rationale: The correct answer is B: Sit upright, leaning slightly forward. This position helps to minimize blood flow to the head, reducing the risk of increased bleeding. It also prevents blood from flowing down the throat, reducing the risk of aspiration. A: Lying supine with the neck extended can increase pressure on the blood vessels in the head, potentially worsening the epistaxis. C: Blowing the nose and putting lateral pressure can disrupt any clots that may have formed and increase bleeding. D: Holding the nose while bending forward at the waist can lead to blood flowing down the throat and increase the risk of aspiration.

Correct Answer: D

Rationale: The correct answer is D, decreased body temperature and cold intolerance, because these are classic signs of hypothyroidism due to decreased thyroid hormone levels. The body's metabolism slows down, leading to a lower core body temperature and reduced ability to tolerate cold. Exophthalmos and conjunctival redness (choice A) are associated with hyperthyroidism. Flushed, warm, moist skin (choice B) is indicative of hyperthyroidism as well, due to increased metabolic rate. A systolic murmur at the left sternal border (choice C) is not a common finding in hypothyroidism.