Explain how renin/angiotensin/aldosterone regulate arteriolar resistance and blood pressure. How can ACE inhibitors reduce hypertension?

Expert Solution

The renin–angiotensin–aldosterone system (RAAS) is a hormone system that regulates blood pressure and fluid and electrolyte balance, as well as systemic vascular (arteriolar) resistance.

When renal blood flow is reduced, juxtaglomerular cells in the kidneys convert the precursor prorenin (already present in the blood) into renin and secrete it directly into circulation.

Plasma renin then carries out the conversion of angiotensinogen, released by the liver, to angiotensin I.

Angiotensin I is subsequently converted to angiotensin II by the angiotensin-converting enzyme (ACE) found on the surface of vascular endothelial cells, mostly present in the lungs.

Angiotensin II is a potent vasoconstrictive peptide that causes blood vessels to narrow, resulting in increased blood pressure.

Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex.

Aldosterone causes the renal tubules to increase the reabsorption of sodium and water into the blood, while at the same time causing the excretion of potassium to maintain electrolyte balance. This increases the volume of extracellular fluid in the body, which also increases blood pressure.

This whole mechanism occurs only when the kidney and the baro-receptors in the arch of aorta has sensed low blood pressure.

When there is enough rise in the blood pressure, a negative feed-back mechanism occurs where in the renin secretion is stopped and later the aldosterone release aswell resulting in inhibiting the rise of blood pressure any further.

If this mechanism is altered, any changes will lead to hypertension.

ACEI- these are Angiotensin- Converting-Enzyme-Inhibitors, these prevent the conversion of angiotensin I to angiotensin II, which is a potent vasoconstrictive peptide.This results in inhibition of aldosterone release from the adrenal cortex aswell along with reduction of blood pressure.

EXAMPLES- captopril, enalapril, lisiopril etc.

GOOD LUCK!

HAPPY STUDYING!!

Sydney Mullin answered 1 year ago

Discuss briefly the mechanisms that regulate arterial blood pressure including the sympathetic nervous system, the renin–angiotensin–aldosterone...

Discuss briefly the mechanisms that regulate arterial blood pressure including the sympathetic nervous system, the renin–angiotensin–aldosterone system (RAAS), and renal function.

State the cause of elevated blood pressure in essential hypertension. Explain how compensation by the renin-angiotensin...

State the cause of elevated blood pressure in essential hypertension. Explain how compensation by the renin-angiotensin pathway aggravates hypertension. What is the cause of weak peripheral pulses when the iliac artery is blocked? How does gangrene develop in arterial PVDs and why may healing following amputation to treat gangrene be reduced? Explain how leg ulcers may develop in people with varicose veins.

3- Please EXPLAIN the Renin-Angiotensin-Aldosterone axis.

Describe the mechanisms of blood pressure regulation for renin angiotensin system.

1. Explain how/why Beta-blockers and ACE inhibitors would work to reduce blood pressure (ie, what ASPECT...

1. Explain how/why Beta-blockers and ACE inhibitors would work to reduce blood pressure (ie, what ASPECT of blood pressure is affected, and how is it affected

1. Explain the renin - angiotensin- aldosterone system (RAAS). Be sure to describe the role of...

1. Explain the renin - angiotensin- aldosterone system (RAAS). Be sure to describe the role of each organ, hormone, and enzyme involved, as well as elaborate on why such a system is necessary even though the kidney is able to regulate glomerular filtration rate through vasoconstriction and vasodilation of the afferent and efferent arterioles. 2). This man has a long history of infectious bronchitis. Why would this chronic smoker be especially susceptible to infections of the bronchi? 3). Explain why...

The Renin-Angiotensin-Aldosterone Pathway and the roles that the kidney plays in the human body and how...

The Renin-Angiotensin-Aldosterone Pathway and the roles that the kidney plays in the human body and how it works to keep the body in balance. Include what happens if there is a homeostatic imbalance as it plays this role.

Explain the role of ADH, Renin, Aldosterone, Angiotensin I, II in water and sodium reabsorption and...

Explain the role of ADH, Renin, Aldosterone, Angiotensin I, II in water and sodium reabsorption and how this is regulated. Also include how this impacts blood volume, blood pressure, and cardiac output. Make sure to include the importance of the lungs and liver in this process as well. Feel free to create a diagram as your explanation. Diagram a Renal Corpuscle with a Nephron Loop including all of the following items and the role they play in the process of...

A decrease in blood pressure will trigger Select one: a. Renin levels to increase b. Aldosterone...

A decrease in blood pressure will trigger Select one: a. Renin levels to increase b. Aldosterone levels to increase c. ADH levels to increase d. All of the above e. None of the above

There’s a class of drugs used to treat high blood pressure known as ACE-Inhibitors. As you...

There’s a class of drugs used to treat high blood pressure known as ACE-Inhibitors. As you might guess from the name, these drugs work by inhibiting the enzyme ACE. a. Explain in detail how an ACE-inhibitor would work to lower blood pressure. (5 points) b. What effect will ACE-inhibitors have on the volume of urine produced? Explain why. (3 points)

Question