Juxtaglomerular apparatus, Biology

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.

Posted Date: 1/16/2013 2:10:36 AM | Location : United States







Related Discussions:- Juxtaglomerular apparatus, Assignment Help, Ask Question on Juxtaglomerular apparatus, Get Answer, Expert's Help, Juxtaglomerular apparatus Discussions

Write discussion on Juxtaglomerular apparatus
Your posts are moderated
Related Questions

Explain the Dietary Management of Sepsis and MODS? Patients suffering from sepsis and/or resultant multiple system organ dysfunctions are critically ill and admitted in the int

Byproducts of the food industry, such as coffee residues, fruit pulp and cocoa meal are of low energy value, but are relatively high in nitrogen. In additional, animal excreta tend

History of Psychiatric Nursing: In 1873, Linda Richards, developed better nursing care in psychiatric hospitals, and organized nursing services and educational programmes  in

What are protein hydrolysates? Proteins that have been treated with enzymes to break them down into amino acids or shorter peptides are referred to as protein hydrolysates.

What is the connection among this substance, mouth bacteria and tooth decay? Mouth bacteria use sugar for their metabolism and produce acids as a waste-product. The acids diss

Limb Regeneration in Amphibians In vertebrates, the amphibians particularly the urodeles comprise spectacular power of regeneration. This power of regeneration has made them

Derived Proteins These are not naturally occurring proteins and are obtained from simple proteins by the action of enzymes and chemical agents, heat, mechanical shaking, UV or

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Q. How does the circulatory system participate in the functioning of the endocrine system? The circulatory system is basic for the functioning of the endocrine system and the b