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

Zoology, why phylum protozoa is called protozoa?

why phylum protozoa is called protozoa?

Indications for surgery-pericardial effusion, Pericardial Effusion:  Indica...

Pericardial Effusion:  Indications for Surgery: Pericardial effusion may be the result of peiicarditis due to infection, autoimmune disease or neoplasm. Non-inflammatoly diseases

Gas exchange and cellular respiration, Q What is the difference between res...

Q What is the difference between respiration meaning gas exchange and cellular respiration? Respiration meaning gas exchange is the process in which an organism absorbs from th

State the study of linked genes, Why is drosophila a convenient animal for ...

Why is drosophila a convenient animal for the study of linked genes? The fruit fly drosophila is suitable for the study of Genetics because it shows many distinct traits but on

Explain extracellular and intracellular digestion, Q How different are extr...

Q How different are extracellular and intracellular digestion? What is the evolutionary advantage of extracellular digestion? Intracellular digestion is that in which the break

Cardiac resynchronization therapy, This innovative, pacemaker-based approac...

This innovative, pacemaker-based approach to the treatment of patients with heart failure who have a wide QRS complex (>140 ms) on 12-lead ECG aims at providing electromechanical c

Define the primary stain and mordant, Define the Primary Stain and Mordant?...

Define the Primary Stain and Mordant? (i) Primary Stain - Crystal violet is the primary or first stain, which stains all the cells violet/purple. (ii) Mordant - Gram's iodin

Breifly describe the menstrual cycle, Breifly describe the Menstrual Cycle?...

Breifly describe the Menstrual Cycle? Each month during a female's reproductive years, the hypothalamus secretes a hormone that stimulates the anterior lobe of the pituitary gl

Pollen biology, Pollen Biology Fluorescence microscopy coupled with bi...

Pollen Biology Fluorescence microscopy coupled with biochemical analysis has helped resolve the differential activity of the enzyme, β-l, 3- glucanase that catalyses the disso

Why is rubella during gestation a threat to the fetus, Why is rubella durin...

Why is rubella during gestation a threat to the fetus? If occurring during gestation rubella is a dangerous disease due to the virus crosses the placenta and contaminates the f

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