Introduction to renal tubular epithelial cell edema

I believe everyone is familiar with the condition of renal tubular epithelial cell edema, right? Perhaps many people have only heard of this situation, but they don’t actually know much about the renal tubules. So what exactly is the renal tubule as a component of our body? Let’s discuss it together.

Renal tubule is a slender epithelial tubule connected to the wall of the renal capsule, which has reabsorption and secretion functions. The renal tubule is divided into three parts according to its different morphological structure, distribution location and function: the proximal tubule, the loop of Medullary and the distal tubule.

Function

The proximal tubule can be divided into a straight part and a curved part. Its curved part is also called the proximal tubule, which is located in the cortical labyrinth and is highly coiled near the renal corpuscle. Under the electron microscope, the cavity surface has a large number of densely and regularly arranged microvilli, which is the brush border under the light microscope. In addition to the junctional complex, there are many lateral processes on the side of the cell. The lateral processes of adjacent cells are intertwined, making the cell boundaries unclear. There are well-developed plasma membrane folds at the cell base, and a large number of basal longitudinal striations and microvilli of proximal convoluted tubules are present in the cytoplasm between the folds. Structures such as lateral processes and plasma membrane infolding are closely related to its function. The function of the proximal tubule is primarily reabsorption.

The distal tubule curvature is also called the distal convoluted tubule and is located in the cortical labyrinth.

The distal convoluted tubule is shorter than the proximal convoluted tubule, so its cross-section in the cortical labyrinth is smaller than that of the proximal convoluted tubule. The distal convoluted tubule is basically similar to the straight part in structure, but the epithelial cells are slightly larger than the straight part, the basal longitudinal striations and plasma membrane infolds are not as developed as those in the straight part, and the number of mitochondria in the plasma membrane infolds is smaller. The function of the distal convoluted tubule is to continue to absorb water and sodium ions. It also secretes potassium ions, hydrogen ions and ammonia into the lumen, which plays an important role in maintaining the acid-base balance of the blood. Aldosterone secreted by the adrenal glands and antidiuretic hormone from the posterior pituitary gland have a regulatory effect on this segment.

Features

The average length of the renal tubule is about 30 to 50 mm, and it is composed of a single layer of epithelium. The characteristics of each segment are as follows:

1. Proximal tubule This tube is connected to the renal capsule cavity and is the thickest section of the renal tubule, coiling around the renal corpuscle to which it belongs. The tube wall is composed of a single layer of cuboidal epithelial cells. The lumen is small and irregular and is an important part of the renal tubular reabsorption function. The free surface of the cell has a brush border, which is composed of microvilli visible under an electron microscope. These structures expand the cell surface area and facilitate reabsorption.

2. The distal convoluted tubule is shorter. It is coiled around the renal corpuscle to which it belongs and is adjacent to the proximal tubule. The tube wall is composed of cuboidal epithelial cells, and the lumen is large and regular. Its end is connected to the collecting duct. The loop of Medullary and the distal convoluted tubule are collectively called the distal nephron. It is an important site for ion transport and secretion. The cells can absorb H2O and Na ions, and excrete K ions, H ions, and NH3. It is regulated by aldosterone and antidiuretic hormone and participates in the regulation of urine concentration and diluteness.

Through the introduction of the above article, I believe everyone has a certain understanding of the renal tubules? The renal tubules play an important role in our body, so if someone around us suffers from renal tubular epithelial cell edema, we must persuade them to seek treatment early to avoid other diseases.