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The nephron is the main structural and functional unit of the kidney, the organ that makes up our urinary-genital system. Despite its small size, it is responsible for many vital functions: it filters the blood, stabilizes the hormonal balance and maintains the correct electrolyte balance. There are about a million nephrons in our body, and this number is not stable – in some cases a kidney may consist of up to four million nephrons. 30% efficient nephrons are required for the proper functioning of organs. They consist of two basic parts: the nerve body, which contains the glomerulus and the glomerular capsule, and the renal tubule.
Nephron – construction
Renal corpuscle is composed of glomerulus a strange and adjacent network Bowman handbags. The aforementioned strange network is a network of blood vessels, i.e. arteries: draining and afferent, branching one by one into capillaries, and then reuniting back into the primary ones. Internal mesangium, which is a type of connective tissue, fills the space between the networks glomerulus. While in the composition glomerulus bags two laminae enter: the inner (it is made of a single-layer epithelium and adheres directly to the capsule) and the outer, which is composed of the same epithelium but has a basal membrane as opposed to the inner lamina. Number of cells making up glomerulus it changes with age – at the beginning of life, there are about 2800 of them in our body. It is worth knowing that renal corpuscle it consists of two poles: vascular (at this point the outer lamina penetrates into the inner one) and tubular (here the lumen of the capsule penetrates the proximal canal). Nephron It also has a kidney tubule built of a single-layer epithelium, the properties of which allow for a simple and quick transfer of ions and other organic compounds. The tubule consists of the first order spiral tubule – proximal (resulting from the narrowing of the capsule), the Henle loop (composed of the ascending and descending limbs) and the distal – distal tubule (the last part of the nephron connected directly with the collecting channel).
Nephron – functions
Each item nephron performs a specific function. In kidney corpuscle thanks to the filtration process, primary urine is formed – filtered blood that does not contain morphotic components and proteins. An interesting fact is that during a day the kidneys can produce up to 170 liters of primary urine, and the final urine we excrete is only 1,5 liters. The filtered plasma formed in the pouch is collected in the part that separates the inner and outer lamina, called the pouch lumen. glomerulus. Then in the tubule, thanks to the cycles of resorption (absorption of some compounds formed in urine into the body) and secretion (removal of unnecessary substances), the final urine is produced. The proximal tubule is responsible for the absorption of the necessary substances, the Henle loop is responsible for the concentration and dilution of urine, and the reabsorption of water, which also aims to concentrate the urine, takes place in the distal tubule. The final urine ends up in the renal pelvis.
How does a nephron work?
Filtering blood and producing urine is possible largely due to the strange mesh. The high blood pressure that is present there allows the fluid to pass through the capillaries into the capsule glomerulus and thus absorbing the necessary substances (minerals, salt and water).
Nephron – diseases
Diseases affecting the kidneys may be genetic or may be caused by external factors. Each of the diseases leads to the exclusion of other diseases from the functions nephronswhich results in the excessive work of others. The first type of disease is divided into: interstitial (caused by stones that accumulate in the renal pelvis) and glomerular (resulting from bacterial infections and causing acute organ inflammation). To destructive diseases nephron we also include polycystic disease (cyst formation at the site of the renal parenchyma), tumors of the urinary system and kidneys. Any diseases affecting these organs should be consulted with a specialist in this field of medicine, i.e. a nephrologist. We receive a referral to him from the GP.
Hormonal regulation of kidney function
Vasopressin is a hormone produced by the hypothalamus. Its task is to reduce the amount of urine excreted while increasing the permeability of the distal membrane. A deficiency of this hormone can cause diabetes insipidus, which can be cured with drugs or surgery.