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

How many different genotypes are possible, If three different traits are co...

If three different traits are controlled by the unlinked genes A, B, and C, and each has multiple alleles so that A has 4 alleles, B has 6 alleles and C has 2 alleles, how many dif

Requirements of glutamine in diverticular disease, Q. Requirements of Gluta...

Q. Requirements of Glutamine in diverticular disease? Glutamine: Wile specific nutrients that may have an impact on diverticula disease have not been studied as thoroughly as t

What is contact plate method - food microbiology, What is Contact Plate Met...

What is Contact Plate Method? Contact Plate (RODAC - Replicate Organism Direct Agar Contact) Method - Contact plates are special petri plates containing suitable agar media wit

What is subphylum vertebrata explain, What is Subphylum Vertebrata explain?...

What is Subphylum Vertebrata explain? This large group of animals takes its name from its distinguishing feature: the vertebral column, or the backbone. The backbone made of se

To study the structure of a seed, To study the structure of a seed Soak...

To study the structure of a seed Soak seeds of bean, pea, pumpkin, sunflower, corn and other large forms. Take away the seed- coats and carefully cut the seeds open. Discover t

Sorbic acid and its salts -preservative, Normal 0 false fa...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Carbon dioxide concentration in photosynthesis process, Q. Why is carbon di...

Q. Why is carbon dioxide concentration a limiting factor of the photosynthesis process? And When the carbon dioxide concentration is increased indefinitely is photosynthesis also i

Explain kingdom monera, Kingdom Monera The monerians are structurally t...

Kingdom Monera The monerians are structurally the simplest of all living things. They have apparently changed little since they first appeared on the earth. Their structure is

Threatened species - wildlife, Threatened Species - Wildlife Many plan...

Threatened Species - Wildlife Many plant and animal species are threatened by the possibility of extinction. However, the seriousness of the threat varies. For example, a spec

Food borne infections, Q. Food borne infections? Food borne infections,...

Q. Food borne infections? Food borne infections, as you may recall reading earlier, are caused by the ingestion of pathogenic microorganisms that penetrate the intestinal muco

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