Yohimbine is an antagonist of receptors.

Correct Answer: B

Rationale: Yohimbine is an antagonist of α2 receptors. The correct answer is B) α2. Yohimbine is a specific antagonist of α2 adrenergic receptors, blocking their activity. In the context of the peripheral nervous system, α2 receptors play a role in regulating sympathetic nervous system activity. By blocking α2 receptors, yohimbine can lead to increased sympathetic activity. Option A) α1 is incorrect because yohimbine does not target α1 receptors. α1 receptors are involved in vasoconstriction and smooth muscle contraction. Option C) both (a) and (b) is incorrect because yohimbine specifically targets α2 receptors, not α1 or both. Option D) None of the above is incorrect as we have established that yohimbine acts as an antagonist of α2 receptors. Understanding the specific receptor targets of drugs is crucial in pharmacology to predict their effects and potential side effects. By knowing that yohimbine targets α2 receptors, healthcare professionals can anticipate its impact on the sympathetic nervous system and make informed decisions when prescribing or administering this drug.

Correct Answer: A

Rationale: In the case of a patient with a corneal ulcer, the most suitable mydriatic would be Atropine sulfate (Option A). Atropine sulfate is a potent anticholinergic agent that causes pupillary dilation (mydriasis) by blocking the parasympathetic stimulation of the iris sphincter muscle. This dilation helps in alleviating pain associated with corneal ulcers by reducing ciliary muscle spasm and preventing synechiae formation. Homatropine (Option B), Cyclopentolate (Option C), and Tropicamide (Option D) are also mydriatics, but they are less suitable for a corneal ulcer patient. Homatropine and Cyclopentolate have shorter durations of action compared to Atropine sulfate, which is needed for prolonged mydriasis in corneal ulcer cases. Tropicamide has the shortest duration of action and is more commonly used for routine ophthalmic examinations due to its rapid onset and short-lived mydriatic effect. In an educational context, understanding the appropriate use of mydriatics in ophthalmology is crucial for healthcare professionals, especially those working in eye care settings. Knowing the specific indications for each mydriatic helps in providing optimal treatment for patients with different ocular conditions, such as corneal ulcers. By grasping the pharmacological properties and clinical applications of these drugs, healthcare providers can make informed decisions to ensure the best outcomes for their patients.

Correct Answer: C

Rationale: The correct answer is C) By a nonexocytotic process. In the context of the release of noradrenaline from adrenergic nerve endings, the process induced by tyramine is nonexocytotic. This means that tyramine does not cause the release of noradrenaline through the typical process of vesicle fusion and exocytosis. Instead, tyramine acts by displacing noradrenaline from intracellular storage sites, leading to its release into the synaptic cleft through a process that does not involve vesicle fusion. Option A) By depolarizing the axonal membrane is incorrect because tyramine does not induce noradrenaline release by causing depolarization of the axonal membrane. The mechanism is different. Option B) By mobilizing Ca2+ is incorrect because tyramine-induced noradrenaline release does not primarily involve the mobilization of calcium ions. While calcium does play a role in neurotransmitter release in general, it is not the primary mechanism in this case. Option D) Only in the presence of MAO inhibitors is incorrect because tyramine can induce noradrenaline release regardless of the presence of monoamine oxidase (MAO) inhibitors. MAO inhibitors are more related to the breakdown of noradrenaline rather than its release. In an educational context, understanding the mechanisms of neurotransmitter release is crucial in pharmacology, especially when studying drugs that impact the peripheral nervous system. Knowing how tyramine influences noradrenaline release can provide insights into its effects and potential interactions with other drugs or conditions that may affect neurotransmitter dynamics. This knowledge is important for healthcare professionals when managing patients receiving medications that impact the peripheral nervous system.

Correct Answer: D

Rationale: In this quiz question, the correct answer is option D: Inhibiting peripheral glucose utilization. Adrenaline, also known as epinephrine, raises blood glucose levels through various mechanisms. Adrenaline stimulates the liver to break down glycogen into glucose (hepatic glycogenolysis) and promotes the release of glucose into the bloodstream. It also enhances the release of glucagon from pancreatic alpha cells, which further increases blood glucose levels. Additionally, adrenaline inhibits insulin secretion from pancreatic beta cells, which would normally promote the uptake of glucose by peripheral tissues. Options A, B, and C are incorrect because they describe actions that adrenaline actually does take to raise blood glucose levels. Inducing hepatic glycogenolysis (option A) increases the availability of glucose in the blood. Inhibiting insulin secretion (option B) prevents the uptake of glucose by cells, leading to higher blood glucose levels. Augmenting glucagon secretion (option C) also contributes to elevating blood glucose levels. Understanding the effects of adrenaline on blood glucose regulation is important in the context of pharmacology and clinical practice. Nurses, pharmacists, and other healthcare professionals need to be aware of how drugs like adrenaline can impact glucose levels, especially in patients with diabetes or other conditions affecting blood sugar regulation. This knowledge is crucial for safe and effective medication administration and management of patients' overall health.

Correct Answer: C

Rationale: In this scenario, the correct answer is C) Mephentermine. Mephentermine is a sympathomimetic amine that acts by stimulating alpha and beta adrenergic receptors, leading to increased peripheral vascular resistance and, consequently, an increase in blood pressure. This makes it an appropriate choice to address hypotension during surgery. Option A) Noradrenaline is also a vasoconstrictor that can raise blood pressure; however, it is typically administered intravenously for rapid effect, not intramuscularly. Option B) Isoprenaline is a non-selective beta-adrenergic agonist that primarily causes vasodilation and increased heart rate, which could potentially worsen hypotension in this case. Option D) Isoxsuprine is a vasodilator that would not be suitable for raising blood pressure in a hypotensive patient. Educationally, understanding the pharmacological properties of drugs used to manage hemodynamic instability is crucial for healthcare professionals, especially those involved in perioperative care. Selecting the appropriate drug based on its mechanism of action and the patient's clinical condition is vital for ensuring optimal outcomes during surgical procedures.