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

Define the ascorbic acid - basic concepts, Define the Ascorbic Acid - Basic...

Define the Ascorbic Acid - Basic Concepts? Ascorbic acid is a water-soluble vitamin, whose structure is shown in Figure. You would have noticed that its structure resembles glu

Metanephridia - excretion, Normal 0 false false false E...

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

Stomata - water loss, Stomata - Water Loss The cross-section of a leaf...

Stomata - Water Loss The cross-section of a leaf shown in Figure shows the position of a typical stoma (plural stomata) which however, differs from species to species, with re

Explain urine urea nitrogen - nutrition during stress, Explain Urine Urea N...

Explain Urine Urea Nitrogen - Nutrition during Stress? 5 gm/24 hrs. = No stress 5 to 10 gm/24 hr = mild hyper-metabolism or level 1 stress 10 to 15 gml24 hrs = moderat

Enhancer, The enhancer is the cis-acting nucleotide series to which the tra...

The enhancer is the cis-acting nucleotide series to which the transcription factor(s) bind, and which increases transcription of the gene. It is not part of the promoter; the gener

What are food hydrocolloids, What are food hydrocolloids? Food hydroco...

What are food hydrocolloids? Food hydrocolloids are hydrophilic polymers of vegetable, animal, microbial or synthetic origin that generally contain many hydroxyl groups and ma

Comparing the dna of a calfs liver and thymus, When comparing the DNA of a ...

When comparing the DNA of a calfs liver and thymus, which would be predicted to have more DNA and why? What are the differences of the DNA between the two?

Treatment and nursing management of cleft lip, Treatment and Nursing Manage...

Treatment and Nursing Management The initial treatment is surgical repair of  the cleft. The timing of the repair varies from surgeon to surgeon, but most prefer cleft lip rep

Viruses, what are viruses?its history?its life cycle and the diseases cause...

what are viruses?its history?its life cycle and the diseases caused by it?

Explain the frank furcal perforation, Explain the Frank Furcal Perforation ...

Explain the Frank Furcal Perforation a) Coronal perforation at the pulpal floor of multirooted tooth. b) Due to excessive deepening at the pulpal floor during access perfora

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