Pathophysiology Final Exam

Correct Answer: D

Rationale: When serotonin levels increase, more neurotransmitters will cross the synaptic cleft and bind with postsynaptic receptors, facilitating enhanced communication. Option A is incorrect because chemical synapses, unlike electrical synapses, are unidirectional. Option B is incorrect because neurotransmitters impact communication with multiple neurons, not just a single connected neuron. Option C is incorrect because neurotransmitters cross the synaptic cleft, not gap junctions.

Correct Answer: B

Rationale: The correct answer is B: 'Present in various sizes.' Anisocytosis refers to erythrocytes that are present in various sizes, indicating an abnormality in the uniformity of red blood cell size. Choice A is incorrect because anisocytosis does not refer to the color of erythrocytes. Choice C is incorrect as anisocytosis does not involve the shape of erythrocytes. Choice D is incorrect as anisocytosis does not determine the lifespan of erythrocytes.

Correct Answer: A

Rationale: The correct answer is A: Tamoxifen may increase the risk of venous thromboembolism. Patients on tamoxifen should be educated about the signs and symptoms of blood clots. Choices B, C, and D are incorrect. Tamoxifen does not decrease the risk of osteoporosis; it may cause hot flashes and other menopausal symptoms, and it may cause weight gain and fluid retention.

Correct Answer: B

Rationale: The correct answer is B: Trigeminal neuralgia. Trigeminal neuralgia is characterized by severe, stabbing pain in the distribution of the trigeminal nerve, often triggered by light touch, chewing, or brushing teeth. In this case, the patient's symptoms of sharp, intermittent facial pain triggered by activities like chewing and touching her face are classic for trigeminal neuralgia. Choices A, C, and D are incorrect. Temporal arteritis typically presents with unilateral headache, jaw claudication, and visual symptoms. Migraine headaches are usually throbbing in nature and often associated with nausea, vomiting, and sensitivity to light and sound. Cluster headaches are characterized by severe unilateral pain around the eye with autonomic symptoms like lacrimation and nasal congestion.

Correct Answer: B

Rationale: The correct answer is B: 'Use of nitrates.' Sildenafil (Viagra) is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates and sildenafil both cause vasodilation, and their combined use can lead to a dangerous drop in blood pressure. Choices A, C, and D are incorrect because a history of hypertension, recent use of antihypertensive medications, or a history of peptic ulcer disease are not direct contraindications for using sildenafil.