The functional unit of the kidney is called the nephron or nephron . It is a complex structure made up of elements such as the loop of Henle , the distal convoluted tubule , the proximal convoluted tube and the renal glomerulus .
Each kidney has more than a million nephrons, responsible for filtering the blood to reabsorb useful substances and expel the rest through urine . Nephrons are tubes with metabolically active walls, which are linked to a large number of blood vessels.
It is important to highlight that nephrons play a relevant role in homeostasis , which is the organic property responsible for guaranteeing internal stability through exchanges of energy and matter with the outside.
Various organisms have a property called homeostasis , which allows them to maintain a certain level of stability within themselves. To do this, they compensate for the changes that take place around them by exchanging matter and energy in a regulated manner. In other words, it is a dynamic balance that is due to a series of control systems that make up self-regulation mechanisms. Alkalinity and acidity (pH) balance and temperature regulation are two common examples of this property.
Through the afferent arterioles, the blood plasma reaches Bowman's capsule , where the glomeruli are located. Then the filtered fluid reaches the proximal convoluted tube so that another filtration is carried out and part of the water , glucose, sodium and amino acids are reabsorbed. The process continues in the collecting duct , the loop of Henle and the distal convoluted tube , continuing the successive filtrations and exchanges of substances.
Below we will see each of the parts of the nephron in detail. The first of them is the renal corpuscle , which performs the first filtration in the kidney and has two structures, mentioned above: the glomerulus , a series of very small capillary tubes; a Bowman's capsule , which resembles a sac, within which is the glomerulus.
On the other hand is the proximal convoluted tubule , whose approximate measurements are 15 millimeters in length and 55 nanometers in diameter. It has walls formed by a single layer of cubic-shaped cells whose luminal side has microvilli called "brush borders" that collaborate with reabsorption , the most important function of the tubule, which absorbs a portion of the nutrients so that the rest passes through. to the loop of Henle.
The loop of Henle , precisely, is a tube whose shape resembles that of a "U" . Its name refers to Friedrich Gustav Jakob Henle , the German scientist who discovered it. This part of the nephron connects the proximal and distal convoluted tubule. Depending on its length , it is possible to speak of a cortical nephron or a juxtamedullary nephron , depending on whether it is short or long.
Finally, we have the distal convoluted tubule , a nephron duct that is characterized by its impermeability to water, although it is permeable to certain ions. It allows a certain amount of sodium chloride to be filtered.
For the treatment of various disorders and diseases , drugs that act on the nephrons are given. Diuretics , for example, are responsible for inhibiting the capacity for water retention, resulting in an increase in the amount of urine produced. Edema and high blood pressure are some of the problems that are treated by influencing the functioning of the nephrons.
This is because the nephrons are very important in regulating the body's fluids, and for this reason they have great clinical relevance.