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

Process for estimation of sucrose by fehling soxhlet method, Explain Proced...

Explain Procedure for Estimation of Sucrose by Fehling Soxhlet Method? Follow the proceedure enumerated herewith and carry out the experiment: 1. Standard titration (Standar

Explain the functions of folate, Explain the Functions of Folate? Folate,...

Explain the Functions of Folate? Folate, also known as folic acid, is essential for good health. Folate requiring reactions include those involved in phases of amino acid metabol

In vitro studies - nutrition of embryo, In vitro Studies - Nutrition of Emb...

In vitro Studies - Nutrition of Embryo Studies involving culture of embryos excised of various stages of development (i.e., early globular proembryo, late globular proembryo o

Arboriculture, Arboriculture : It deals with the cultivation of ornamental ...

Arboriculture : It deals with the cultivation of ornamental plants. Arboriculture is the cultivation, management or study of individual shrubs, trees, vines, or other perennial woo

Respiratory system in fishes, The fishes belong to class Pisces under verte...

The fishes belong to class Pisces under vertebrates. 2. In fishes, the respiratory system consists of mouth, pharynx, internal branchial apertures, branchial pouches and external b

Genetic, 1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) a...

1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) are all found on the X-chromosome of Drosophila melanogaster. All of these are recessive traits. They map in the or

Describe the parathyroid hormone, A new drug named ANTAG-CaSR has been deve...

A new drug named ANTAG-CaSR has been developed that is an antagonist at calcium-binding sites of CaSRs (Calcium-Sensing Receptors) in the plasma membranes of parathyroid gland cell

What is the adp phosphorylation, Q. What is the ADP phosphorylation? What r...

Q. What is the ADP phosphorylation? What respectively are oxidative phosphorylation and photophosphorylation? ADP phosphorylation is the addition of one inorganic phosphate in

Complications in celiac disease, Q. Complications in celiac disease? Pa...

Q. Complications in celiac disease? Patients with severe form of celiac's disease for long period are at risk for several complications mainly due to nutrient absorption probl

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