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

Which alpha-helices would not be found in a protein, Please explain the dif...

Please explain the differences between an integral membrane protein, a Davison-Danielli peripheral membrane protein, and a protein in which alpha-helices would not be found.

Types of lysosomes, TYPE S OF LYSOSOMES (1 )      Primary Lysosomes ...

TYPE S OF LYSOSOMES (1 )      Primary Lysosomes or storage granules or protolysosome - The primary lysosomes are smaller in size, they contain hydrolytic enzyme in the form

What do you mean by periodical, Q. What do you mean by Periodical? A pe...

Q. What do you mean by Periodical? A periodical is a publication appearing at regular intervals. Each issue is called a number and collectively these numbers comprise a volume.

Explain holding method of pasteurization, Explain holding method of pasteur...

Explain holding method of pasteurization In the holding method of pasteurization (62 o C for 30 minutes) or the high-temperature short-time (HTST), 71 o C for 15 minutes method

Fertilisation, Fertilisation: Fertilisation is the process of fusion...

Fertilisation: Fertilisation is the process of fusion of male and female gametes. For fusion of male and female gametes, pollen grains have to reach the surface of the stigm

Formation of primary urine in malpighian tubules, Normal 0 fals...

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

Lab: 7 Osmosis, Tonicity and the plant cell. Table 3: Amount of water displ...

Tonicity and the plant cell. Table 3: Amount of water displaced by potato samples before and after experiment?

How hiv infection works, How do antibody-based tests detect how HIV infecti...

How do antibody-based tests detect how HIV infection works? After the infection by the HIV the immune system starts the production of antibodies (primary immune response) again

Define tips that should be followed before an event start, Define Tips that...

Define Tips that should be followed before an event Start? Before the event, following tips should be followed:   As the glycogen stores may be used up during night, a h

Hypomagnesemia, H y p o ma g n e s e m i a It is also known...

H y p o ma g n e s e m i a It is also known as grass staggers or lactation or grass tetany and results in clonic and tonic muscular spasms and convulsions. E

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