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

What is the evolutionary origin of the internal membranous, What is the evo...

What is the evolutionary origin of the internal membranous organelles of the cell? It is accepted that the internal membranous organelles of the eukaryotic, like the Golgi app

Metallurgical coke, Metallurgical coke should have following characteristic...

Metallurgical coke should have following characteristics: 1.      Purity: low amounts of moisture, ash, sulphur & phosphorous should be present. 2.      Porosity: it should b

Alteration of turgor of guard cells, Alteration of Turgor of Guard Cells ...

Alteration of Turgor of Guard Cells There are two ways in which the relative turgor of guard cells may be altered. A decrease in osmotic potential or A decre

Prevention and control from escherichia coli, Q. Prevention and Control fro...

Q. Prevention and Control from escherichia coli? Prevention and Control: Involves avoiding contaminated food and water that have high coliform counts, avoiding unpasteurized ju

Energy and protein deficiencies, Energy and protein deficiencies Defic...

Energy and protein deficiencies Deficiencies of protein and energy are the most common nutrient deficiencies, which adversely affect production and performance of farm animals

Use of computer in biotechnology, what are the uses of computer in biotechn...

what are the uses of computer in biotechnology ??? briefly explain any twenty

What are tannins, What are Tannins? Long known for their inhibitory eff...

What are Tannins? Long known for their inhibitory effects on iron absorption, recent research indicates that tannins do have beneficial effects. Tannins are compounds of high m

Chlamydiosis-prevention and control, Prevention and control The organism i...

Prevention and control The organism is sensitive to penicillin, tetracycline and other broad-spectrum antibiotics. Newer generation drugs are being used for the treatment of affec

What is st segment depression at rest, Q. What is ST segment depression at ...

Q. What is ST segment depression at rest? ST- segment depression has become severe, that is, 3 to 4mm or more in vigorous asymptomatic subjects. If the patient is known to have

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