Which hormone is secreted by adrenal medulla & is involved in fight & flight response

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2024

Applied Physiology

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2024

Explanation

Epinephrine (also known as adrenaline) is a catecholamine hormone secreted by the adrenal medulla.
It is the primary hormone responsible for initiating the 'fight-or-flight' response, a rapid and widespread reaction to acute stress.
The effects of epinephrine include increased heart rate, elevated blood pressure, bronchodilation, and mobilization of glucose from storage for immediate energy.
The adrenal medulla functions as part of the autonomic nervous system, releasing hormones directly into the bloodstream for a systemic effect.

Option A: Cortisol is secreted by the adrenal cortex, not the adrenal medulla. It is a glucocorticoid primarily involved in the body's long-term stress response, metabolism, and immune suppression, not the immediate fight-or-flight reaction.
Option C: Aldosterone is secreted by the adrenal cortex, not the medulla. It is a mineralocorticoid that primarily regulates sodium and potassium balance, thereby managing blood volume and blood pressure.
Option D: Insulin is secreted by the beta cells of the pancreas, not the adrenal glands. Its function is to lower blood glucose levels by promoting glucose uptake into cells, which is contrary to the needs of a fight-or-flight response.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Hormones of the Adrenal Gland and Fight-or-Flight Response as background academic context rather than a clinical decision trigger.
Understanding the role of epinephrine is crucial in emergency medicine. Synthetic epinephrine is a first-line treatment for anaphylaxis, cardiac arrest, and severe asthma attacks due to its potent effects on the cardiovascular and respiratory systems.
Nurses monitor for the effects of excess catecholamines in patients with conditions like pheochromocytoma (a tumor of the adrenal medulla), which presents with hypertension, palpitations, and headaches.
What if? If the question asked for the hormone from the adrenal medulla that primarily acts as a neurotransmitter in the sympathetic nervous system and causes vasoconstriction, the answer would be Norepinephrine. While also involved in fight-or-flight, it has a more pronounced effect on blood vessels.

How to Approach the Question

First, identify the key terms in the question: 'hormone', 'adrenal medulla', and 'fight & flight response'.
Recall the basic anatomy of the adrenal gland, differentiating between the outer cortex and the inner medulla.
Associate the adrenal medulla with the secretion of catecholamines (epinephrine and norepinephrine) and its link to the sympathetic nervous system.
Associate the 'fight-or-flight' response specifically with epinephrine (adrenaline).
Evaluate each option: Cortisol and Aldosterone are from the cortex with different functions. Insulin is from the pancreas. This leaves Epinephrine as the only correct choice.

Concept Tested & Keywords

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