Juxtaglomerular apparatus, Biology

Assignment Help:

Juxtaglomerular Apparatus

The autoregulation of renal blood flow involves a neuroendocrine mechanism related to the juxtaglomerular apparatus in the kidney.

1896_Juxtaglomerular apparatus.png

 Figure: Structure of the juxtaglomerular apparatus in mammals

When the afferent arterial blood pressure is low, the stretch sensitive receptors of the arterioles initiate nerve impulses which induce the secretion of a proteolytic enzyme called renin by the juxtaglomerular cells into the blood. This enzyme causes the release of a decapeptide called angiotensin-I from a large globular plasma protein known as angiotensinogen. Another proteolytic enzyme from the plasma, the converting enzyme, removes two amino acids from angiotensin-I to form an octapeptide called angiotensin-II. Angiotensin-II is about 200 times more powerful than norepinephrine in its lasopressor activity. It increases the blood pressure by two mechanisms. Firstly, it acts on the smooth muscle of the arterioles and causes strong vasoconstriction. Secondly, it stimulates the secretion of aldosterone by the adrenal cortex. Aldosterone enhances the uptake of Na+ by the kidney tubules and hence causes a rise in the plasma Na+ level. This results in an increase in the extracellular fluid volume and consequently an elevation in blood pressure. Angiotensin-II is degraded by an enzyme called Angiotensinase, present in plasma.


Related Discussions:- Juxtaglomerular apparatus

Sickle Cell, Sickling occurs in deoxyhemoglobin S, but not in oxyhemoglobin...

Sickling occurs in deoxyhemoglobin S, but not in oxyhemoglobin S. Oxyhemoglobin has a small hydrophobic \"pocket\" in a ß chain region located in the interior of the protein. In de

Why did it not drop more give reason, Mr. Smith read that cholesterol was b...

Mr. Smith read that cholesterol was bad for his health so he eliminated all foods and food products containing this molecule. He later found that his cholesterol level dropped only

What is the primary structure of a protein, What is the primary structure o...

What is the primary structure of a protein? What is the importance of the primary structure? Ans) The primary protein structure is the linear sequence of amino acids that produc

Why do most of plants present opposite phyllotaxis, Why do most of plants p...

Why do most of plants present opposite phyllotaxis? The Phyllotaxis is the way that leaves are arranged on shoots. Most of plants have opposite phyllotaxis that (alternating in

Define termination phase - mechanism of protein synthesis, Define Terminati...

Define Termination phase - mechanism of protein synthesis? Termination: RNA polymerase recognizes the terminator, which results in no further nucleotides being incorporated and

Maternity and child health & family planning, M A TERNIT Y AND CHILD HEA...

M A TERNIT Y AND CHILD HEALTH & FAMILY PLANNING - 1.       The health centers give necessary information, guidance & assistance to mother before & after delivery pregnant wo

How can amine groups be classified, How can amine groups be classified? ...

How can amine groups be classified? Amines can be classify into primary amines, those to which one -R (variable radical) is attached to a -NH2, secondary amines, those where on

Types of amoeboid movements, Types of Amoeboid Movements As the amoeba...

Types of Amoeboid Movements As the amoeba's cell body throws out one or a few pseudopodial lobes, a temporary rear end or uroid is pulled along. The central, more fluid protop

Create a dichotomous key for ant, Create a dichotomous key the following or...

Create a dichotomous key the following organisms, ant, butterfly, fly, beetle, grass hopper, wasp, ladybug, roach and dragonfly.

Why is cartilage more flexible than bone, Why is the cartilage more flexibl...

Why is the cartilage more flexible than bone? in general, why does cartilage take longer to repair than bone?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd