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

Abrasive action of water and wind, Abrasive action of water, ice and wind ...

Abrasive action of water, ice and wind Water is an important mechanical weathering agent both in liquid as well as in the frozen state.  Rain water carrying sediments, ice glac

Anaerobic lagoon system, A n a e r o b i c lagoon system This s...

A n a e r o b i c lagoon system This specific system of liquid manure handling is restricted to organized dairy farms, where the flushed manure is directed into an anae

Captive breeding - measures for species conservation, Captive Breeding - Me...

Captive Breeding - Measures for Species Conservation Species which are reduced to dangerous levels need more intensive management, and one strategy is their captive breeding.

Subphylum mastigophora, Subphylum Mastigophora One or more flagella p...

Subphylum Mastigophora One or more flagella present in adult stages; autotrophic or heterotrophic nutrition; reproduction usually asexual by fission. Class - Phytomasti

Explain clostriduim botulinum, Q. Explain Clostriduim botulinum? Clostr...

Q. Explain Clostriduim botulinum? Clostriduim botulinum is widely distributed in soil and marine sediments throughout the. world. It is also found in the intestinal tract of a

Invertebrate, #question what is the diff, urogenital system of the inverteb...

#question what is the diff, urogenital system of the invertebrae animal?

Theory of natural selection, What key idea, contained in Malthus's essay on...

What key idea, contained in Malthus's essay on populations, helped Darwin formulate his theory of natural selection?

Define risk factors for drug nutrient interaction, Define Clinical Signific...

Define Clinical Significance and Risk Factors for Drug-Nutrient interactions? We are already aware of the fact that poor nutritional status can impair drug metabolism and the d

History - assessment of patents with cardiovascular probems, History P...

History Past and present history of cardiovascular problems of patient & family. History of chest pain, shortness of breath, fatigue, abnormal skin colour, dizziness, vertigo

Explain procedure for checking the presence of rhodamine b, Explain Procedu...

Explain Procedure for Checking the Presence of Rhodamine B? Conduct the experiment following the procedure given herewith: 1. Pour liquid paraffin or mineral oil in a Petri

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