A 6-year-old boy cuts his hand on the training wheel of his bicycle. The wound is 1.5 cm in size and the bleeding stops with direct pressure. One of the steps of blood clotting involved platelet aggregation through activation of collagen. Platelet release of granules is mediated by the release of mediators. Which of the following mediators, if activated, will likely cause bleeding to continue?

Correct Answer: C

Rationale: Platelet aggregation stops bleeding, but serotonin is correct-if defective, bleeding persists. ADP , Thrombin , and Thromboxane A2 (E) promote clotting. Dopamine is unrelated. Serotonin's vasoconstrictive role, if impaired, could prolong bleeding, though less critical than others here.

Correct Answer: D

Rationale: Midazolam is a short-acting benzodiazepine widely used as an anesthetic due to its rapid onset and potent sedative effects. Its mechanism involves enhancing the activity of gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the brain, at GABA_A receptors—not GABA_B receptors, which are linked to different effects like muscle relaxation. By binding to a specific site on the GABA_A receptor, midazolam increases the frequency of chloride channel opening, leading to greater chloride ion conductance into neurons. This hyperpolarizes the neuron, making it less excitable and producing sedation, anxiolysis, and anesthesia. Dopamine enhancement is unrelated to its action, as is NMDA receptor blockade, which is a feature of drugs like ketamine. Partial agonism at serotonin (5HT) receptors also does not apply here. The facilitation of GABA-mediated chloride conductance is the precise mechanism that underpins midazolam's clinical utility as an anesthetic agent.

Correct Answer: D

Rationale: Topiramate, a broad-spectrum antiepileptic, treats generalized tonic-clonic seizures by blocking sodium channels, enhancing GABA, and inhibiting glutamate, making it a first-line option per guidelines. Ethosuximide targets absence seizures. Felbamate, vigabatrin, and ezogabine have narrower uses or toxicity risks (e.g., aplastic anemia, vision loss), limiting them to refractory cases. Topiramate's efficacy, tolerability, and broad action suit primary generalized seizures, distinguishing it as a standard choice.

Correct Answer: D

Rationale: Intranasal corticosteroids (e.g., fluticasone) can cause burning and nosebleeds due to mucosal drying . They're preventive, not symptom-driven (choice B is wrong), and dosing is fixed, not squeeze-dependent . Choice D educates on a common, manageable side effect, ensuring client awareness and compliance.

Correct Answer: D

Rationale: Dextromethorphan with alcohol causes dizziness and hallucinations , guiding the nurse to advise medical help. Dialysis , opioid status , and addiction are incorrect. D informs the response, making it key.