Functions and structure of the nephron

Nephron is not only the main structural, but also a functional unit of the kidney. It is here that the most important stages of urine formation take place. Therefore, information on how the structure of the nephron looks and what functions it performs will be very interesting. In addition, the features of the functioning of nephrons can clarify the nuances of the functioning of the renal system

Structure of the nephron: renal corpuscle

Interestingly, in a mature kidney of a healthy person is from 1 to 1.3 billion nephrons. Nephron is a functional and structural unit of the kidney, which consists of the kidney body and the so-called loop of Henle.

The renal corpuscle itself consists of the Malpighian glomerulus and the Bowman-Shumlyansky capsule. To begin with, it should be noted that the glomerulus is in fact a collection of small capillaries. Blood enters here through the artery - here the plasma is filtered. The rest of the blood is excreted by the outgoing arteriolus.

The Bowman-Shumlyansky capsule consists of two sheets - internal and external. And if the outer sheet is an ordinary tissue of flat epithelium, then the structure of the inner leaf deserves more attention. The inner part of the capsule is covered with podocytes - these are cells that serve as an additional filter. They miss glucose, amino acids and other substances, but interfere with the movement of large protein molecules. Thus, the primary urine is formed in the renal corpus, which differs from the blood plasma only by the absence of large molecules.

Nephron: the structure of the proximal tubule and the loop of Henle

The proximal tubule is the formation that connects the renal corpuscle and the Henle loop. Inside the tubule has villi, which increases the total area of the internal lumen, thereby increasing the reabsorption.

The proximal tubule smoothly passes into the descending part of the Henle loop, which is characterized by a small diameter. The loop descends into the medullary layer, where it traverses its own axis 180 degrees and rises upwards - here begins the ascending part of the loop of Henle, which has much larger dimensions and, accordingly, the diameter. The ascending loop rises to about the level of the glomerulus.

Structure of the nephron: distal tubules

The ascending part of the Henle loop in the cortical substance passes into the so-called distal sinuous canaliculus. It comes into contact with the glomerulus and contacts the delivery and outboard arterioles. Final absorption of nutrients is carried out here. The distal tubule passes into the terminal compartment of the nephron, which in turn flows into the collecting tube, which carries the fluid into the renal pelvis.

Classification of nephrons

Depending on the location, it is customary to distinguish three main types of nephrons:

• Cortical nephrons account for approximately 85% of the number of all structural units in the kidney. As a rule, they are located in the external cortex of the kidney, which, in fact, is evidenced by their name. The structure of the nephron of this type is slightly different - the Henle loop here is small;
• Juxtamedullary nephrons - such structures are located just between the cerebral and cortical layers, have long Henle loops that penetrate deeply into the medulla, sometimes even reaching the pyramids;
• Subcapsular nephrons - structures that are located directly under the capsule.

It can be seen that the structure of the nephron completely corresponds to its functions.