Do macula densa cells secrete renin?

Do macula densa cells 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.

How does macula densa release renin?

The macula densa is a collection of specialized epithelial cells in the distal convoluted tubule that detect sodium concentration of the fluid in the tubule. The juxtaglomerular cells, derived from smooth muscle cells, of the afferent arteriole secrete renin when blood pressure in the arteriole falls.

Which cells are responsible for renin secretion?

Renin is an enzyme secreted by the juxtaglomerular cells of the kidney. It interacts with aldosterone in a negative-feedback loop.

What is the work of macula densa?

Macula densa (MD) cells are chief cells within the kidney, playing key sensory and regulatory functions in the maintenance of body fluid, electrolyte homeostasis, and blood pressure.

What do macula densa cells regulate?

Macula densa cells monitor intratubular salt concentrations to regulate renal blood flow via afferent arteriole constriction and dilation. The juxtaglomerular cells also contain renin granules, which can send out a wider signal to control vascular resistance through the renin-angiotensin-aldosterone pathways.

What triggers secretion of renin?

The secretion of renin is stimulated by the following three factors: When a fall in arterial blood pressure is detected by pressure sensitive receptors (baroreceptors) in the arterial vessels. When a decrease in sodium chloride (salt) is detected in the kidney by the macula densa in the juxtaglomerular apparatus.

What do macula densa cells release?

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.

Where is the macula densa found?

The macula densa plaque is a unique group of 15 to 20 cells located at the end of the cortical thick ascending limb forming a juxtaglomerular apparatus-glomerular complex.

What stimulates Juxtaglomerular cells?

The juxtaglomerular cell is a cell that is located near the glomerulus, hence its name. Similar to cardiac tissue, juxtaglomerular cells harbor β1 adrenergic receptors. When stimulated by epinephrine or norepinephrine, these receptors induce the secretion of renin.

What is macula densa literal mean?

Medical Definition of macula densa. : a group of modified epithelial cells in the distal convoluted tubule of the kidney that lie adjacent to the afferent arteriole just before it enters the glomerulus and control renin release by relaying information about the sodium concentration in the fluid passing through the convoluted tubule to the renin-producing juxtaglomerular cells of the afferent arteriole.

How do macula densa cells detect low blood pressure?

The decrease in the glomerular filtration rate is sensed by the macula densa (they are closely packed cells) present lining the glomerulus in the distal tubule. They sense the lower levels of sodium ions which indicate low blood pressure. It causes an increase in sodium absorption. Water moves in by osmosis and increases the plasma volume.

What is the lateral meaning of macula densa?

macula densa. Etymology: L, macula, spot, densus, thick. a thickening in the wall of a distal tubule of the kidney nephron at a point where it is in contact with the afferent glomerulus and in direct opposition to the juxtaglomerular cells.

What does the macula densa monitor?

As part of the body’s blood pressure regulation, the macula densa monitors filtrate osmolarity; if it falls too far, the macula densa causes the afferent arterioles of the kidney to dilate, thus increasing the pressure at the glomerulus and increasing the glomerular filtration rate.