Homepage - - - Tutorial Index

Normal Histology

Glomeruli - Interstitium - Tubules - Vessels

Interstitium

It is the support tissue of renal parenchyma. In histology, it corresponds to the space between glomeruli, tubules, vessels and nerves. It is scant in the cortex and abundant in the medulla.

It is composed of cells and extracellular fibrillar structures, proteoglycans, glycoproteins and fluid. The cells are of two types: fibroblasts and cells of the immune system that have migrated (monocytes/macrophages, dendritic cells and lymphocytes). The cortical fibroblasts produce erythropoietin.

The peritubular interstitium corresponds to the 7-9% of the cortical volume and usually is fused with basement membranes of the tubules and capillaries. The periarterial interstitium surrounds the intrarenal arteries and finishes throughout the afferent arterioles, and contains lymphatic and nerves. In the periarterial interstitium the fibroblasts, apparently, do not synthesize erythropoietin.

The lymphatics are embedded in the periarterial tissue, they start in the vicinity of the afferent arterioles running the arterial course toward the hilium.

The intrarenal nerves run alongside the arteries in the periarterial connective tissue. There are independent autonomic nerves for the vessel walls, juxtaglomerular apparatus, and some fibres contact the pars convolute of the proximal tubule.

Figure 1. In the cortex the interstitium is scant. It is the support tissue that surrounds tubules, peritubular capillaries, glomeruli, vessel and nerves. (H&E, X400).

Figure 2. In the medulla there is progressively more interstitial tissue when deepening from the cortex. (H&E, X400).

Figure 3. The nerves accompany the vessel. They are immersed in the interstitial perivascular tissue. (H&E, X400).

Figure 4. The stains in which the collagen is emphasized allow to identify better the interstitium. Here it is seen of green colour, surrounding an artery (left) and a nerve (right). (Gomori’s trichrome, X300).

[Top]

Histology: Glomeruli - Tubules - Vessels

Homepage - - - Tutorial Index