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

Composition-atmosphere, Composition The present day composition of atmo...

Composition The present day composition of atmosphere is the product of a lengthy evolutionary process that began more than four billion years ago. It is composed of a mixture

Explain procedure for the use of light microscope, Explain Procedure for th...

Explain Procedure for the use of Light Microscope? Now carry out the exercise following the steps enumerated herewith. 1. Place the microscopic slide with any specimen on th

State the effects of smoking for diabetics patient, State the Effects of al...

State the Effects of alcohol and smoking for diabetics patient A major concern with alcohol consumption is the potential danger of hypoglycaemia (low blood sugar), especially w

The neural impulse is transmitted along the axon, What is the mechanism by ...

What is the mechanism by which the neural impulse is transmitted along the axon? The neural impulse is transmitted with the neuronal membrane through depolarization of consecu

Ecosystem, what is the main excretory organ of a lizard

what is the main excretory organ of a lizard

Show non-modifiable risk factors for cardiovascular disease, Q. Show Non-Mo...

Q. Show Non-Modifiable Risk Factors for cardiovascular disease? Age: Earlier men less than 55 years were more prone but now heart disease has caught up with a younger age-gro

What is the importance of vitamin B2, What is the Importance of vitamin b2 ...

What is the Importance of vitamin b2 As a prosthetic group of the flavin enzymes, vitamin B 2 is involved in the reactions of almost all nutrients of plants and animals. They

Recombinent DNA, any interesting information about recombinent DNA

any interesting information about recombinent DNA

Define the basic function of keratin in the epidermis, Q. What is the funct...

Q. What is the function of keratin in the epidermis? The epidermis is the outer layer of the skin made of epithelial tissue in the epidermis there are keratin-secreting cells (

Centrolecithal egg, which type of cleavage takes place in centrolecithal eg...

which type of cleavage takes place in centrolecithal egg

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