O nephron and the functional unit of kidney, that is, the structure responsible for the formation of urine in these organs. The human body has two kidneys, which are shaped like a bean and are part of our urinary system. In each kidney there are approximately 600 to 800,000 nephrons.
Read more: The formation of urine
Nephrons can be classified as cortical nephrons and juxtamedullary nephrons. Corticals have loops that reach only a small part of the kidney medulla, while juxtamedullary ones go deep into the medulla.
→ the nephrons
Nephrons are formed by a globular region and a long tube. These regions are named as follows:
Basic organization of a nephron
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Renal corpuscle: is formed by two parts, the glomerulus and the renal capsule or capsule of bowman, which is cup-shaped and surrounds the glomerulus. Glomeruli are a series of arterial capillaries with elevated hydrostatic pressure compared to other capillaries. This pressure causes the blood fluid to be forced out of the glomerulus into the interior of the capsule, forming the glomerular filtrate.
Nephrons receive blood from a afferent arteriole (arteriole that carries blood to the glomerulus), an offshoot of the renal artery that branches and forms the glomeruli. These capillaries leave the glomerulus and converge to form a efferent arteriole (which takes the blood out of the glomerulus).
Read more: chronic kidney failure
Proximal convoluted tubule: this part of the nephron receives the glomerular filtrate, which will undergo the process of absorption and excretion of substances.
Handle of Henle: this loop is U-shaped, consisting of a descending branch and an ascending branch. It's where the retention of part of the water.
Distal contorted tubule: in this portion of the nephron will be made ion exchanges, occurring sodium absorption and potassium secretion. This tube opens into the collecting duct, which will be responsible for receiving the material produced in the nephrons (urine) and transporting it to the renal pelvis.
It is clear, therefore, that the nephron it's a complex structure that guarantees the filtration of blood and the removal of substances which are in excess or are toxic to our body. That's why we say the nephron is a functional unit of the kidney.
By Ma. Vanessa dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/biologia/o-que-e-nefron.htm
