What is mesangium in kidney?
Mesangial cells are specialised cells in the kidney that make up the mesangium of the glomerulus. Together with the mesangial matrix, they form the vascular pole of the renal corpuscle. The mesangial cell population accounts for approximately 30-40% of the total cells in the glomerulus.
What is glomerulus histology?
The renal corpuscle consists of several histological structures (FIG 1): Glomerulus capillaries form a central tuft of looped capillaries located in the center of the renal corpuscle. These capillaries deliver blood and create a large surface area for renal filtration. These capillaries are optimized for filtration.
What is the histology of the proximal convoluted tubule?
First, the proximal convoluted tubule – which is the longest part of the renal tubule – has a simple tall cuboidal epithelium, with a brush border (microvilli). The epithelium almost fills the lumen, and the microvilli increases the surface area by 30-40 fold.
What is mesangial cell function?
Mesangial cells play a central role in glomerular function, modulating glomerular capillary blood flow and ultrafiltration surface area. In addition, mesangial cells are both a source of and target for vasoactive molecules, growth factors, cytokines, and extracellular matrix proteins.
Is mesangium part of glomerulus?
The mesangium forms the central core of the glomerular tuft. The processes which they extend towards the GBM are densely populated by bundles of actin, myosin, and β-actinin microfilaments.
What does glomerulus look like?
The glomeruli are small round clusters of capillaries (microscopic blood vessels) that are surrounded by a double-walled capsule, called Bowman’s capsule. Bowman’s capsule in turn connects with a long tubule. The capsule and attached tubule are known as a nephron.
How do you distinguish between proximal and distal convoluted tubules histology?
1) Staining – proximal tubules are more eosinophilic than the distal. 2) Nuclei – proximal tubule cells have more heterochromatic nuclei than those of distal tubule cells; and there are more nuclei per unit area in the distal tubule than there are in the proximal tubule.
What is the function of the proximal convoluted tubule?
The function of the proximal tubule is essentially reabsorption of filtrate in accordance with the needs of homeostasis (equilibrium), whereas the distal part of the nephron and collecting duct are mainly concerned with the detailed regulation of water, electrolyte, and hydrogen-ion balance.
What is the mesangium in the eye?
The mesangium with its associated cells and matrix is an arborizing structure that supports the glomerular capillary loops but is continuous with the JGA that lies at the junction of the afferent and efferent arterioles and the macula densa of the distal tubule.
Why is the mesangium important to the glomerulus?
The mesangium is an extremely important component of the glomerulus, forming the supporting framework in which the glomerular tuft capillaries ramify. The mesangium includes an extracellular matrix comprising Type IV collagen, proteoglycans, and other proteins, and two cell types.
What is immunoglobulin deposition in the mesangium?
Deposition of immunoglobulins (Ig) or immune complexes in the mesangium is one of the causes of glomerular injury and is seen secondary to diseases like Systemic Lupus Erythematosus (SLE) [ 10] or primary diseases like IgA nephropathy [ 11 ]. Immunoglobulin aggregates activate MCs by signaling through surface Fc Receptors.
What role do mesangial cells play in the pathophysiology of glomerular disease?
The mesangial, endothelial and epithelial cells of the glomerulus are involved in most pathologic processes. Animal models provide an understanding of the molecular basis of glomerular disease. These studies show that mesangial cells are critical players in initiation and progression of disease.