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 are analogies for mitochondria, Explain What are analogies for mitocho...

Explain What are analogies for mitochondria? Ans) Well, as we know, the mitochondria are the producers of lots of a cell's energy and the nucleolus makes ribosome's.

Body temperature and room temperature , You ran both a body temperature and...

You ran both a body temperature and room temperature test for each enzyme you tested. Did the two temperatures seem to have an effect on the enzyme Exercise? Why or why not?

What are the five kingdoms, Q. What are the five kingdoms into which living...

Q. What are the five kingdoms into which living beings are divided? And which group of living being is out of this classification? The five kingdoms of living beings are the ki

What is an antigen, What is an antigen? Antigen is any substance, parti...

What is an antigen? Antigen is any substance, particle or infectious agent known as foreign to the body. The contact of the antigen with the body promotes a defense reaction ag

Blood vitreous barrier as the physio-chemical property, Explain the blood v...

Explain the blood vitreous barrier as the physio-chemical property. Blood Vitreous Barrier: The blood vitreous barrier consists of three components: Tight junctional comp

Cardiac output and its determination, The cardiac output is the volume of b...

The cardiac output is the volume of blood pumped from the heart every minute. It is obtained by the volume pumped with each beat (stroke volume) multiplied by the heart rate. The c

What is the benefit of alternative splicing, Question 1: What is the be...

Question 1: What is the benefit of alternative splicing? Could there also be drawbacks of Alternative splicing? If yes, mention the same. Definitions of alternative splic

Our healthi diet, in what form is most carbohydrates is taken in normal die...

in what form is most carbohydrates is taken in normal diet

Gastro epiploic artery and inferior epigastric artery, Gastro Epiploic arte...

Gastro Epiploic artery GEA is seldom used now. Patency has been reported as 94 per cent at one year, 88 per cent at five years and 83 per cell1 at ten years. Inferior Epiga

Explain wild-type fruitfly drosophila melanogaster, A cross among wild-type...

A cross among wild-type fruitfly Drosophila melanogaster  [normal bristles and grey body (s+s, e+ e)] with a mutant fly [short bristles and ebony body (ss ee)] produces following p

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