What Is the Renal Corpuscle?

Renal corpuscle is a component of the nephron. The renal corpuscle, also called glomerulus, is located in the renal cortex and the renal column. It is the beginning of the nephron. It is swollen like a sphere, with a diameter of 150 to 250 m and an area of 0.1010 to 0.4670 mm². ^] .

Renal corpuscle is a component of the nephron. The renal corpuscle, also known as the glomerulus, is located in the renal cortex and the renal column. It is the beginning of the nephron. It is swollen like a sphere, with a diameter of 150 to 250 m and an area of 0.1010 to 0.4670 mm². ^] .

Chinese name

Renal corpuscle

Foreign name

renal corpuscle

Department

Nephrology

Renal corpuscle development

Renal bodies of different developmental stages can be observed in the same embryo (fetal) age kidney. The deep layer of the cortex is the more mature first-generation renal corpuscle, and the superficial layer is the immature renal corpuscle. According to the degree of maturation of the capillaries and filtration barriers and the size of the renal capsule, we divide the development of the renal corpuscles into three stages: primordial, developmental and mature.

1.1 Primitive stage (I) S: The renal corpuscles are mainly distributed in the superficial cortex and are composed of primitive renal sacs and mesenchymal cell clusters or cords. Observed by electron microscope, the renal capsule was spoon-shaped, consisting of two layers of cells, the cystic cavity between the two layers was narrow. The outer layer (wall layer) cells are cubic, and the inner layer (dirty layer) is columnar. At the same time as the formation of the primitive renal vesicles, the cells in the visceral layer began to differentiate, the cells were densely arranged, and desmosomes and tight junctions were formed between the cells. The nucleus is large, regular, and the organelles gradually increase. The mesenchymal cells in the center of the body are irregularly arranged, the cell volume is large, there are fewer heterochromatin in the nucleus, and the nucleoli are obvious. In the later stage of IS, the development of endothelial cells can be seen in the interstitial cell mass, the cells are thick, the organelles are abundant, and the surrounding basement membrane is thin, and 1-2 cavities can be formed, and red blood cells are occasionally seen in the cavity.

1.2 Developmental stage (S): The renal corpuscles are distributed in the middle cortex, and the renal capsular cavity and vascular bulbs are formed during this period. The cells of the renal capsule wall layer gradually changed from cubic to flat, with rough endoplasmic reticulum, mitochondria, and Golgi complex developed, and a few short finger-like protrusions at the free end extended into the capsule cavity. Visceral cells changed from columnar to cubic or wedge-shaped, and arranged in a single layer or multiple layers around the vascular bulb. The cytoplasm increased, the Golgi complex was developed, the rough endoplasmic reticulum was abundant, and the mesh pool was filled with flocs of medium electron density.

1.3 Maturity (S): Renal corpuscles are distributed deep in the cortex. The renal capsule space was significantly enlarged, and the number of capillaries was increased. The filter membrane developed well. According to our observation, there are about 3 generations of renal corpuscles in the embryonic kidney from the superficial layer to the deep layer at 8 weeks, of which about 10% of the renal corpuscles have reached IIS, and about 20% of the fetal kidneys have 8 generations of renal corpuscles, of which about 30% of the kidneys The body reaches IIIS. There were about 10 generations of renal corpuscles in the fetal kidney at 28 weeks, and about 50% of them had IIIS.

Glomeruli (5 photos)

Renal body composition

1. The vascular bulb has two poles: the vascular pole and the urinary pole. The blood vessels have the arteriolar arterioles into which the blood flows and the arteriolar arteries that lead out of the blood. There is a small amount of connective tissue cells at the extreme part of the blood vessel. It enters the blood vessel with the blood vessel and is distributed between the capillaries of the blood vessels. . The opposite end is called the urinary pole where it is connected to the renal tubule.

2. The Bowman capsule has two layers, the wall and the viscera. The visceral epithelial cells are also called podocytes. There is a thick and intact layer between podocytes and capillary endothelial cells or between podocyte protrusions and the mesangium. Base film.

Function

The function of the renal corpuscle is ultrafiltration. The filtration barrier is made up of capillary endothelium, vascular basement membrane, and pore membrane of podocytes. The core of the glomerulus is a globular vascular network, which has a filtering function, which can filter out the blood cells in the blood and the macromolecular proteins in the plasma. Its two ends are connected to the inferior and superior bulbar arteries, respectively. The arteriolar arteries are thick and straight, and the efferent arterioles are thin and curved, so that a significant pressure difference is formed between the efferent arteries and the efferent arteries, which makes the pressure in the glomeruli very high, which is beneficial to the kidneys. Filtration of Capillary Capillaries.

If there is a problem with the glomeruli, red blood cells and macromolecular proteins may leak out, forming hematuria and proteinuria.

A funnel-shaped sac wrapped around the glomerulus is the glomerulus. The renal capsule is divided into two layers, the inner layer is close to the glomerulus, and the outer layer is connected to the tubular wall. A renal capsule cavity is formed between the two layers, and the renal capsule cavity communicates with the renal tubular cavity. The function of the renal capsule is to generate raw urine and send it into the renal tubules.