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

Consider a ph scale while answering, What is the relationship of hydrogen i...

What is the relationship of hydrogen ion concentration in tomato juice relative to lemon juice and to pure water? Be as quantitative as you can (i.e., use numbers to describe the m

Aortic allograft -biological valves, Aortic Allograft (Homograft) :  ...

Aortic Allograft (Homograft) :  In the earlier years fresh antibiotic preserved aortic allografts were tried. As the shelf life is limited, availability of all sizes at all t

What is specific defence mechanism, What is Specific defence mechanism ...

What is Specific defence mechanism Specific:  These relate to specialized cells located throughout the  body which respond to invasion of foreign materials/microorganisms  su

Phylum protozoa, what is holozoic, holophytic, saprozoic nutrition

what is holozoic, holophytic, saprozoic nutrition

Explain about the obliques muscles, Explain about the Obliques muscles ...

Explain about the Obliques muscles The superior and inferior oblique muscles form an angle of about 51 0 with the optical axis. The oblique muscles produce cyclorotation becau

Role of dietitian in health care, Role of Dietitian in Health Care The ...

Role of Dietitian in Health Care The role of the dietitian has come a long way since the early 1900s. Their role is still unknown to a  lot of people. Some think that dietitian

Biothw, Determine sequence weights for the sequences ACTA, ACTT, CGTT, and ...

Determine sequence weights for the sequences ACTA, ACTT, CGTT, and AGAT in problem 1 by using Thompson, Higgins, and Gibson method

Principles governing cleavage, Principles Governing Cleavage a) The n...

Principles Governing Cleavage a) The nucleus and mitotic achromatic figure tend to occupy the centre of active cytoplasmic density of the dividing cells, e.g., in isolecithal

Catalogue of larval forms in various animal groups, Catalogue of Larval For...

Catalogue of Larval Forms in Various Animal Groups The larval stages and types found in different groups are many. Each larval type has a different structure and is known by a

Differentiation - morphogenesis and tissue organisation, Differentiation - ...

Differentiation - Morphogenesis and Tissue Organisation It should be clear to you that a single cell, the fertilized egg, gives rise to various structures that we mentioned. S

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