Renin catalyzes the synthesis of angiogenesis which causes vasoconstriction in the kidney thereby?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Applied Physiology

Hard

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Explanation

The question describes the Renin-Angiotensin-Aldosterone System (RAAS), which is a critical regulator of blood pressure and fluid balance.
Renin, released by the kidneys, initiates a cascade that produces angiotensin II.
Angiotensin II stimulates the adrenal cortex to secrete the hormone aldosterone.
Aldosterone's primary function is to act on the kidney's distal tubules and collecting ducts to increase the reabsorption of sodium (an electrolyte) and water.
This process leads to the retention of water and electrolytes, which increases blood volume and, consequently, blood pressure.

Option A: This is the opposite of the RAAS's function. The system is activated to raise blood pressure by conserving fluid, not by excreting it.
Option C: The RAAS does not stimulate the synthesis (creation) of minerals. It regulates the retention or excretion of existing minerals, primarily sodium.
Option D: Melatonin is a hormone produced by the pineal gland in the brain and is primarily responsible for regulating the sleep-wake cycle (circadian rhythm). It has no direct link to the renin-angiotensin system.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Renin-Angiotensin-Aldosterone System (RAAS) as background academic context rather than a clinical decision trigger.
The RAAS is a fundamental target in pharmacology for managing hypertension. Common antihypertensive drugs like ACE inhibitors (e.g., Ramipril, Enalapril) and Angiotensin II Receptor Blockers (ARBs) (e.g., Losartan, Telmisartan) work by interrupting this pathway.
Nurses play a vital role in monitoring patients on RAAS inhibitors for therapeutic effects (lower blood pressure) and adverse effects, such as hypotension, hyperkalemia (high potassium), and a persistent dry cough (with ACE inhibitors).
What if? If a patient has heart failure, the RAAS is often chronically over-activated, leading to fluid overload and worsening cardiac function. In this case, RAAS inhibitors are a cornerstone of therapy to reduce the workload on the heart and manage fluid retention.

How to Approach the Question

First, identify the key terms in the question: 'Renin', 'vasoconstriction', and 'kidney'.
Recognize that 'angiogenesis' is an obvious typo for 'angiotensin', as renin is the enzyme that initiates the Renin-Angiotensin system.
Recall the physiological pathway of the Renin-Angiotensin-Aldosterone System (RAAS).
Trace the sequence of events: Renin leads to the formation of Angiotensin II.
Remember the two main actions of Angiotensin II: causing vasoconstriction and stimulating the release of aldosterone.
Focus on the final step: Aldosterone acts on the kidneys to promote the reabsorption of sodium and water.

Concept Tested & Keywords

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