Question: What Is A Juxtaglomerular Apparatus?

What activates Juxtaglomerular cells?

Juxtaglomerular Cells Although they are activated by prostaglandins released from the macula densa cells, they can also release renin independently of the macula densa.

Baroreceptors found in the arterioles trigger renin secretion if there is a fall in blood pressure in the arterioles..

Is renin a hormone?

Renin is a central hormone in the control of blood pressure and various other physiological functions.

What do macula densa cells 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 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.

What enzyme is released by the Juxtaglomerular complex to regulate GFR?

ReninRenin is an enzyme that is produced by the granular cells of the afferent arteriole at the juxtaglomerular apparatus.

What causes aldosterone secretion?

Aldosterone secretion is stimulated by an actual or apparent depletion in blood volume detected by stretch receptors and by an increase in serum potassium ion concentrations; it is suppressed by hypervolemia and hypokalemia.

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.

Why is renin secreted?

Renin’s primary function is therefore to eventually cause an increase in blood pressure, leading to restoration of perfusion pressure in the kidneys. Renin is secreted from juxtaglomerular kidney cells, which sense changes in renal perfusion pressure, via stretch receptors in the vascular walls.

What is the role of the Juxtaglomerular apparatus?

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 are Juxtaglomerular cells?

Renin is produced and stored in granular juxtaglomerular (JG) cells, which are modified aortic smooth muscle cells found in the media of afferent arterioles. These cells synthesize the precursor prorenin, which is cleaved into the active proteolytic enzyme renin.

How does Juxtaglomerular cells work?

Urinary System: Juxtaglomerular complex The afferent arteriole in this region contains specialised secretory cells (smooth muscle cells) called juxtaglomerular cells, that secrete renin. These cells do two things: They monitor blood pressure, by measuring how much the arteriole wall is stretched.

Where are Juxtaglomerular cells located?

Juxtaglomerular cells These cells are similar to epithelium and are located in the tunica media of the afferent arterioles as they enter the glomeruli.

What is the renal corpuscle made of?

The nephron is composed of renal corpuscle and renal tubule and is the functional unit of the kidney. The renal corpuscle consists of Bowman’s capsule and glomerular capillaries, responsible for plasma filtration (image A) & (image B). Network of capillaries that invaginate into Bowman’s capsule.

What is the Juxtaglomerular apparatus made up of?

The juxtaglomerular apparatus, located in the glomerular hilum, consists of a vascular component (afferent and efferent arterioles and extraglomerular mesangium) and a tubular component (macula densa).

What stimulates macula densa cells?

A decrease in sodium chloride concentration initiates a signal from the macula densa that has two effects: (1) it decreases resistance to blood flow in the afferent arterioles, which raises glomerular hydrostatic pressure and helps return the glomerular filtration rate (GFR) toward normal, and (2) it increases renin …