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

Where may bacteria be found, Where may bacteria be found? Expose steril...

Where may bacteria be found? Expose sterile bacteria dishes to as lots of the following conditions as you can. Label the dishes and set them away in a warm, dark place for a so

How to list 7 different types of information, List 7 different types of inf...

List 7 different types of information that must be recorded for every item of evidence collected from a crime scene.

Hutchinsons system of classification, Q. Hutchinsons System of Classificati...

Q. Hutchinsons System of Classification? John Hutchinson, a renowned British Botanist proposed 24 phyletic dicta or principles and based on these dicta he published a phylogene

Blood supply of the heart, The heart is supplied exclusively by the right a...

The heart is supplied exclusively by the right and left coronary arteries. The coronary arteries are functional end arteries. There is no effective anastamosis between right and le

How have brain-imaging methods such as pet and mri, How have brain-imaging ...

How have brain-imaging methods such as PET and MRI affected neuroscience research and clinical care? Techniques which capture pictures of the living human brain at work have be

Codex code of practice, Codex code of practice Codex Alimentarious Comm...

Codex code of practice Codex Alimentarious Commission (CAD) was established in 1963 with the objective to develop International Food Safety Standards to protect human health, w

Non-renewable energy sources, In many countries of Asia biomass contributes...

In many countries of Asia biomass contributes l argely as a source of primary energy. People in rural areas at the peripheries of forests, continue to collect fuel wood from adjace

How can we control the disease cholera, How can we control the disease Chol...

How can we control the disease Cholera Control: Individuals infected  with cholera require oral rehydration therapy  with NaCl plus sucrose, sodium bicarbonate and potassium ch

Define safety points that should used in the laboratory, Define Safety poin...

Define Safety points that should used in the Laboratory? You should be aware of the rules/regulations and the procedures before undertaking any practical work in the laboratory

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