Effects of Nicotine will increase the body's secretion of?

SCTIMST Staff Nurse - 2015 (Set-B)

Pharmacology

Easy

Appeared in: SCTIMST Staff Nurse - 2015 (Set-B)

Explanation

Nicotine acts on nicotinic acetylcholine (ACh) receptors in various parts of the body, including the adrenal medulla.
The adrenal medulla functions like a modified sympathetic ganglion.
Stimulation of these receptors on the adrenal medulla's chromaffin cells causes the release of neurotransmitters, primarily epinephrine (adrenaline).
This release of epinephrine into the bloodstream is responsible for many of nicotine's acute cardiovascular effects, such as increased heart rate and blood pressure.

Option A: Thyroxine secretion is primarily regulated by Thyroid-Stimulating Hormone (TSH) from the pituitary gland, not directly by nicotine. While catecholamines can have a minor modulatory effect, it is not the primary mechanism.
Option C: The secretion of pancreatic juices is mainly under parasympathetic control (via the vagus nerve and muscarinic receptors) and hormonal control (secretin and cholecystokinin). Nicotine's primary effect is sympathomimetic, not parasympathomimetic.
Option D: Histamine is released from mast cells and basophils, primarily during allergic reactions and inflammatory responses. It is not a direct result of nicotine's stimulation of the adrenal medulla.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacological effects of nicotine on the endocrine and nervous systems as background academic context rather than a clinical decision trigger.
Nurses must monitor vital signs, especially heart rate and blood pressure, in patients who smoke or are using nicotine replacement therapy (NRT) like patches or gum.
This is particularly critical for patients with pre-existing cardiovascular conditions such as coronary artery disease (CAD), hypertension, or a history of arrhythmias, as nicotine can exacerbate these conditions.
Patient education should include the cardiovascular risks associated with nicotine use and the importance of reporting symptoms like palpitations, chest pain, or dizziness.

How to Approach the Question

First, identify the core subject of the question, which is the physiological effect of a specific substance: nicotine.
Recall the mechanism of action of nicotine. It is a stimulant that acts on nicotinic acetylcholine receptors.
Consider the locations of these receptors. Key sites include autonomic ganglia and the adrenal medulla.
Connect the stimulation of the adrenal medulla to its primary function: the secretion of catecholamines.
Identify the main catecholamine released by the adrenal medulla, which is epinephrine (adrenaline).
Evaluate the given options. Epinephrine is listed, while the other options are controlled by different physiological pathways not directly stimulated by nicotine.

Concept Tested & Keywords

Concept Tested: Pharmacological effects of nicotine on the endocrine and nervous systems.
Stem keywords: Nicotine, increase, secretion
Lead-in keywords: BEST, MOST RELEVANT CLUE

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 768-770

E6 Pharmacology Katzung 16e p. 230-232