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 about gestational diabetes mellitus, Q. Explain about Gestational D...

Q. Explain about Gestational Diabetes Mellitus ? During pregnancy, a woman who does not have a history of diabetes, may develop high blood glucose or sugar. This is GDM. The di

Define excretion of iron in human body, Define Excretion of Iron in Human B...

Define Excretion of Iron in Human Body? Our body has a limited capacity to excrete iron once it has been absorbed. Daily losses in adult man are between 0.9 to 1.05 mg. About 0

What is interpretation of stress echocardiography, Q. What is Interpretatio...

Q. What is Interpretation of Stress Echocardiography? The standard approach to interpretation is qualitative. The attendant need for training and problems posed for reproducibi

Skeletal system - girdles, GIRDLES - (i ) PECTORAL GIRDLE - ...

GIRDLES - (i ) PECTORAL GIRDLE - 4 bones. It is located on posterolateral part of upper region of the throax. It consists of scapula & clavicle. Scapula is placed

Respiration would cease even oxygen and food were supplied, If a tissue was...

If a tissue was heated to 65ºC for 10 minutes, respiration would cease even if oxygen and food were supplied. Why is this? A temperature of 65°C for 10 minutes would denature

Signify asexual and how it is formed, Signify Asexual and how it is formed?...

Signify Asexual and how it is formed? Organisms which do not reproduce by recombination of genetic material contained in gametes. There is not any combination of a haploid sper

Determine the sucrose content in a sample of honey, Q. Determine the sucros...

Q. Determine the sucrose content in a sample of honey? This activity will help you to: • estimate the non-reducing sugars and total sugars in a sample of honey, • check t

Determine about the nervous system and behaviour, Determine about the Nervo...

Determine about the Nervous System and Behaviour Damage to certain parts of the brain will be reflected as behaviour deficits. For example, damage to the temporal lobe may affe

What is hormones explain its role in humun body, What is Hormones explain i...

What is Hormones explain its role in humun body? Hormones are chemical signals that trigger responses in another part of the body. Once secreted, hormones move through the spa

Analytic characters - nature and structure of community, Analytic Character...

Analytic Characters - Nature and Structure of Community As you know a community has its own characteristics. Which are not shown by its individual component species. These cha

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