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

Explain cigrates smoking from lifestyle risk factors, Explain cigrates smok...

Explain cigrates smoking from lifestyle risk factors ? Smoking is the single most important preventable risk factor for CAD. There is strong evidence that smoking can significa

Insects - hormones in growth and reproduction, Insects - Hormones in Growth...

Insects - Hormones in Growth and Reproduction In insects hormones regulate moulting and metamorphosis. The larvae or nymphs which hatch out of the eggs undergo regular moultin

State the enzymes utilization in brewing industry, Enzymes utilization in B...

Enzymes utilization in Brewing Industry Here, the main starting material is malt, produced by allowing barley seeds to germinate under moist conditions. The reserve starch is b

Explain hepatitis c, Hepatitis C It provides sustained viral responses ...

Hepatitis C It provides sustained viral responses (SVRs) of 54% to 63%. When used as monotherapy, peginterferons once weekly are more effective than standard interferon 3 times

Explain trifluridine, Explain Trifluridine  (Viroptic)  Trifluridine is...

Explain Trifluridine  (Viroptic)  Trifluridine is a nucleoside analog active against herpes viruses, including acyclovir-resistant strains. Marketed in an ophthalmic preparatio

Explain anticonvulsants and cerebral palsy, Anticonvulsants and Cerebral Pa...

Anticonvulsants and Cerebral Palsy Anticonvulsants : drugs that prevent reduce or stop convulsions or seizures. Cerebral Palsy: A group of chronic foundations affecting

Define the parathryroid gland, Which of the following serves as an effector...

Which of the following serves as an effector, or part of an effector, that functions in a negative feedback system? A. 1,25-dihydroxyvitamin D Receptors located intracellularly

Define x-ray chest and coronary angiography, Q. Define X-Ray Chest and Coro...

Q. Define X-Ray Chest and Coronary Angiography? X-Ray Chest It shows cardiomegaly with left ventricle (LV) and left atrium (LA) enlargement. There may be signs of pulmona

What is allantois, What is Allantois One of the extraembryonic eggs foun...

What is Allantois One of the extraembryonic eggs found in the amniote animals. The allantois contains the metabolic wastes created by the developing embryo. May also be involved

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