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

Explain enzymes, Explain Enzymes Enzymes are the proteins that  act  ...

Explain Enzymes Enzymes are the proteins that  act  as  catalysts,  speeding the  rate  at which biochemical reactions proceed but not altering  the direction or nature of th

What is the chemical nature of carbohydrates, What is the chemical nature o...

What is the chemical nature of carbohydrates? The name carbohydrate owes its origin to the fact that most substances of this class have empirical formulae suggesting that they

Define direct visualisation of coronary arteries, Q. Define Direct Visualis...

Q. Define Direct Visualisation of Coronary Arteries? Ans. Coronary arteries cad be directly visualized using two-dimensional echocardiography, especially in patients with

The splinter with a sterile needle, joey has a splinter in his finger. His ...

joey has a splinter in his finger. His mother pulled the skin away from the splinter with a sterile needle and removed the splinter. Joey did not feel pain and did not bleed. Expla

What are the factors that for influencing photosynthesis, Q. What are the f...

Q. What are the factors that for influencing photosynthesis also interfere with the gross primary productivity? Mostly light and water, but as well mineral salts, carbon dioxid

Ethidium bromide, Ethidium Bromide  intercalates within structure of the nu...

Ethidium Bromide  intercalates within structure of the nucleic acids in such a manner that they fluoresce under the UV light. Ethidium bromide staining is generally used to visuali

Define hexose monophosphate pathway, Define hexose monophosphate pathway ...

Define hexose monophosphate pathway The hexose monophosphate pathway (HMP also called the pentose phosphate pathway, or phoshogluconate pathway) consists of Mo irreversible o

Water relations in terrestrial environment, Water Relations in Terrestrial ...

Water Relations in Terrestrial Environment Insects are the largest group of metazoans which have most successfully invaded the terrestrial environment. In addition, most arach

Parazoans and simplest metazoans, in what aspect are the cnidarians simila...

in what aspect are the cnidarians similar to the protozoans?

Nucleic acids, Deoxyribonucleic Acid (DNA) - polymer of nucleotides contai...

Deoxyribonucleic Acid (DNA) - polymer of nucleotides containing genetic information that codes for proteins Nucleotide - a monomer of DNA consisting of a ribose/deoxyribose sug

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