Question: What Is Juxtaglomerular Nephron?

What does the macula densa secrete?

Macula densa cells in the distal nephron, according to the classic paradigm, are salt sensors that generate paracrine chemical signals in the juxtaglomerular apparatus to control vital kidney functions, including renal blood flow, glomerular filtration, and renin release..

What stimulates macula densa cells?

The cells of the macula densa are sensitive to the concentration of sodium chloride in the distal convoluted tubule. … As such, an increase in sodium chloride concentration would result in vasoconstriction of afferent arterioles, and reduced paracrine stimulation of juxtaglomerular cells.

What do mesangial cells secrete?

Mesangial cells are also specialized cells and have many important functions. They secrete an extracellular matrix substance (mesangial matrix) rich in laminin and fibronectin that helps support the capillary tuft. Some mesangial cells contain actomyosin filaments and are contractile.

What is the significance of Juxtaglomerular apparatus JGA in kidney function?

The juxtaglomerular apparatus is a specialized structure formed by the distal convoluted tubule and the glomerular afferent arteriole. It is located near the vascular pole of the glomerulus and its main function is to regulate blood pressure and the filtration rate of the glomerulus.

What does the Juxtaglomerular apparatus do?

The juxtaglomerular apparatus functions to maintain blood pressure and to act as a quality control mechanism to ensure proper glomerular flow rate and efficient sodium reabsorption. The urethra extends from the bladder to the surface of the body. It consists of an epithelium-lined lumen and a smooth muscle layer.

What is the Juxtamedullary nephron?

In other words, a juxtamedullary nephron is a nephron whose renal corpuscle is near the medulla, and whose proximal convoluted tubule and its associated loop of Henle occur deeper in the medulla than the other type of nephron, the cortical nephron.

How does Juxtaglomerular apparatus regulate the kidney function?

The juxtaglomerular apparatus (JGA) is a control unit of the kidney, that regulates glomerular filtration rate (GFR) and renin release, and hence extracellular volume and blood pressure. The tubuloglomerular feedback (TGF) mechanism is a negative feedback loop that regulates GFR.

Does the macula densa secrete renin?

The macula densa participates in the regulation of renin release from juxtaglomerular granular cells. Renin secretion depends on NaCl delivery to and reabsorption by the macula-densa cells at the end of the TAL.

What three hormones factors do the kidneys secrete into the blood?

The kidney secretes (1) renin, a key enzyme of the renin-angiotensin system (RAS) that leads to the production of a potent pressor hormone angiotensin, and produces the following hormones and humoral factors: (2) kallikreins, a group of serine pro- teases that act on blood proteins to produce a vasorelaxing peptide …

What are Juxtaglomerular cells?

The juxtaglomerular cells (JG cells, or granular cells) are cells in the kidney that synthesize, store, and secrete the enzyme renin. They are specialized smooth muscle cells mainly in the walls of the afferent arterioles (and some in the efferent arterioles) that deliver blood to the glomerulus.

What is nephron and its function?

Nephron, functional unit of the kidney, the structure that actually produces urine in the process of removing waste and excess substances from the blood. … The most advanced nephrons occur in the adult kidneys, or metanephros, of land vertebrates, such as reptiles, birds, and mammals.

What does renin hormone do?

Renin, enzyme secreted by the kidney (and also, possibly, by the placenta) that is part of a physiological system that regulates blood pressure. In the blood, renin acts on a protein known as angiotensinogen, resulting in the release of angiotensin I.