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

What is an operon, What is an operon, and in what type of organism are oper...

What is an operon, and in what type of organism are operons found? An operon is a series of genes that code for exact products and the regulatory elements that control those ge

Intergenic interactions, what are intergenic interactions ? please explain ...

what are intergenic interactions ? please explain with example of cross breeding. and how we calculate the phenotype and genotype. explain epistasis, duplicate genes, supplementary

Phylum , General characteristics of phylum

General characteristics of phylum

What are the nine phyla of the kingdom animalia, Q Which are the beings tha...

Q Which are the beings that form the kingdom Animalia? What are the two big groups into which this kingdom is divided? The kingdom Animalia is the animal kingdom. usually the k

What is meant by gene expression, What is meant by Gene Expression? The...

What is meant by Gene Expression? The synthesis of protein under the influence of gene is called Gene Expression. All human cells are derived from a single cell, fertilized egg

Briefly explain what is the leaf, Briefly explain what is The Leaf? In a ...

Briefly explain what is The Leaf? In a typical dicot, leaf primordia arise from the apical meristem, which is housed within the terminal bud on a shoot. The leaf cells are produc

Aeration, Aeration A well-aerated soil is one in which gases are availa...

Aeration A well-aerated soil is one in which gases are available to plant roots and other soil organisms, in sufficient quantities and in proper proportions to support their no

Explain fats requirements during thyphoid, Explain fats requirements during...

Explain fats requirements during thyphoid Fats: Use of fats should be in moderation. This is because the typhoid patient has a compromised ability to digest and assimilate due

Determine the functional brain activity, Determine the functional brain act...

Determine the functional brain activity PET is powerful means of assessing functional brain activity, although it does not directly measures neuronal events. Rather it indicate

Ratios of different samples of nucleic acid, Ratios of the bases in differe...

Ratios of the bases in different samples of nucleic acid yielded the following results: a.  A + C    =   0.6         b.     A  +  C    =  1            c.       A  + G    =  1.2

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