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

Are environmental phenotypical changes transmitted offspring, Are environme...

Are environmental phenotypical changes transmitted to the offspring? Changes caused on the phenotypes by the environment are not transmitted to the offspring unless their prima

What is the thermopenetration concept, What is the thermopenetration concep...

What is the thermopenetration concept? The pasteurization of products packed in glass containers leads to a problem of a specific nature, which is referred to as 'thermopenetra

Define secondary and tertiary structure of a protein, Is it expected that a...

Is it expected that a change in the primary, in the secondary or in the tertiary structure of a protein will produce more functional consequences? Any change of the protein str

What is population growth rate, Q. What is population growth rate? The ...

Q. What is population growth rate? The Population growth rate (PGR) is the percent variation between the numbers of individuals in a population at two different times. Thus the

What is the equilibrium state of the system, For each of the cases that fol...

For each of the cases that follow, list as many properties of the equilibrium state as you can, specially the constrains placed on the equilibrium state of the system by its surrou

Medical management of chronic renal failure, Medical Management   In ch...

Medical Management   In chronic  renal failure  there  is irreversible renal failure. The goals of medical management are:   To promote maximal  renal  function  To ma

Orthopedics, 1. List alternative therapies for musculoskeletal problems. ...

1. List alternative therapies for musculoskeletal problems. 2. What is a xyrospasm? What is the Greek derivative of the word? 3. Name and describe the three types of varus con

Subphylum uniramia, Subphylum Uniramia Uniramia, the largest subphylu...

Subphylum Uniramia Uniramia, the largest subphylum of phylum Arthropods includes myriapods and insects. Due to the unbranched nature of the appendages of its members, the sub

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