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 bioremediation, What is bioremediation? Bioremediation is the u...

What is bioremediation? Bioremediation is the use of microorganisms, as bacteria, protists and fungi, to degrade noxious substances turning them into non toxic or less toxic su

Define sporangiophore - types of hyphae, Define Sporangiophore - Types of H...

Define Sporangiophore - Types of Hyphae? Sporangiophore - Tufts of special, erect unbranched, hyphae growing in air arise from stolon just opposite to rhizoids. These are s

What is simple transposition in neonates, What is Simple Transposition in N...

What is Simple Transposition in Neonates ? A baby with this malformation needs to be operated without delay. A very cyanosed infant will require palliation by balloon arteries

Explain the dietary management in trauma, Explain the Dietary Management in...

Explain the Dietary Management in Trauma? Trauma As a result of metabolic responses to injury, there is an increase in the energy expenditure. Oxidation of body fat stores take

Explain about the protein-energy ratio, Explain about the Protein-Energy Ra...

Explain about the Protein-Energy Ratio (NDP Cal%)? Platt and his colleagues (1961) are largely responsible for the introduction of the ratio of protein energy to total energy (

Effect of respiratory frequency, Q. How does the pulmonary ventilation affe...

Q. How does the pulmonary ventilation affect the carbon dioxide concentration in blood? What happens to the carbon dioxide concentration and to the blood pH when the respiratory fr

Explain the function of the right ventricle, Q. What is the function of the...

Q. What is the function of the right ventricle? To where does the right ventricle pump the venous blood? The venous blood is carried as of the right ventricle to the lungs by t

Neurons, hpw many neurons do we have?

hpw many neurons do we have?

Structure of myofibril, STRUCTUR E OF A MYOFIBRIL - The dark bands ...

STRUCTUR E OF A MYOFIBRIL - The dark bands of the myofibril are termed the A-bands (Anisotropic bands). Each A-band has at its middle a light zone called H-zone (Henson'

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