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

Gene, Gene  is the fundamental physical and functional unit of the heredity...

Gene  is the fundamental physical and functional unit of the heredity (generally DNA, Some of the organisms have RNA a gene). A gene is an ordered series of nucleotides located in

Syngamy - protozoan, Syngamy - Protozoan The two gametes may be morpho...

Syngamy - Protozoan The two gametes may be morphologically similar (isogametes) or dissimilar (anisogametes). The gametes also vary in form, they may be flagellated or amoeboi

What are important terms in accommodation and convergence, What are importa...

What are important terms in accommodation and convergence? Accommodation and Convergence In this section some important terms are included: a. How a person is able to foc

Which of groups is not ionizable, Which of the following groups is NOT ioni...

Which of the following groups is NOT ionizable? Select one: a. Guanidinium b. Imidazole c. Phosphoryl d. Amine e. Aldehyde

Events prior to the sperm-egg fusion, Events prior to the Sperm-Egg Fusion ...

Events prior to the Sperm-Egg Fusion In a number of organisms that have been studied, the sperm remain immotile in the testis or in the semen. The sperm become active and mot

Explain about the adolescent pregnancy, Explain about the Adolescent Pregna...

Explain about the Adolescent Pregnancy? The pregnant adolescent is viewed as a high-risk patient, highly susceptible to suboptimal pregnancy outcome. Even when not pregnant, a

Nomenclature, who proposed the trinominal nomenclature

who proposed the trinominal nomenclature

Molybdenum (mo), Molybdenum (Mo) Mo is absorbed as molybdate (MOO 2- ...

Molybdenum (Mo) Mo is absorbed as molybdate (MOO 2- 4 ) ion by plants. Its uptake can be competitively reduced by SO 2- 4 . The requirement of plants for Mo is very low. Mo

Non-protein amino acids, NON-PROTEI N AMINO ACIDS Non-protein amino ac...

NON-PROTEI N AMINO ACIDS Non-protein amino acids are the ones which are not incorporated in proteins but occur freely or in combined state in non-protein substances. Their

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