Nephron

 Nephron 

The nephron or nephron is the basic structural and functional unit of the kidney, responsible for blood purification. Its main function is to filter waste from the blood to regulate water and soluble substances, reabsorbing what is necessary and excreting the rest as urine. It is located mainly in the renal cortex.


Discription

The nephron is the functional unit of the renal parenchyma. In humans, each kidney contains around 800,000 to 1,000,000 nephrons.[1] The structure of the nephron is complex, it is composed of a renal corpuscle in communication with a renal tubule. The Malpighian renal corpuscle is a spheroidal structure, made up of Bowman's capsule and the capillary ball contained inside or glomerulus. The capsule, lined internally by a flattened epithelium, has two openings: the vascular pole, through which the afferent arteriole penetrates and the efferent arteriole emerges, and the urinary pole, which communicates with the renal tubule. The urinary space extends between the capsule and the glomerular tuft, where the plasma ultrafiltrate is collected.


 The nephron is an important part of the homeostatic mechanism, which regulates through filtration, absorption and excretion the amount of water, salts, glucose, as well as urea, and many other metabolites of the catabolism of fats, lipids, proteins and we can also observe that in the nephron there are important proteins.

Functions 

The functioning of the nephron is based on an exchange of ions that begins when blood plasma enters Bowman's capsule (which contains the glomeruli) via an afferent arterial route. From the aforementioned Bowman's capsule, the filtered fluid passes to the proximal convoluted tube in which the primary filtration is carried out where the sodium, water, amino acids and glucose are partially reabsorbed due to the semipermeable composition of the walls.


 Along the way from the proximal convoluted tube to the collecting duct, the fluid undergoes absorption of substances and also the discharge of others. These changes occur in different sections such as the aforementioned proximal convoluted tube, as well as in the descending and ascending sections of the Loop of Henle and in the distal convoluted tube. Calcium and potassium ions, as well as excess water and other salts (waste), end up in the collecting duct....

Clinical relevance


 Because of its importance in regulating body fluid, the nephron is a common target of drugs that treat high blood pressure and edema. These drugs, called diuretics, inhibit the nephron's ability to retain water, therefore increasing the amount of urine produced.


 Renal corpuscle


 In the glomerulus, fluid is collected from the blood in Bowman's capsule to form the "glomerular filtrate", which will then be processed along the renal tubule to form urine. Bowman's capsule: it is a structure similar to a sac that surrounds the glomerulus and filters the substances that are going to be excreted. This process is called glomerular filtration.


 Proximal convoluted tubule


 The proximal tubules are part of the nephron, a system that filters and reabsorbs components of the blood that passes through the kidneys. Its walls are composed of a single layer of cubic cells.


 Handle of Henle


 The loop of Henle is made up of two portions: a thin descending portion that is very permeable to water absorption, and a thick ascending portion which is very permeable to ions and impermeable to water.


 Distal convoluted tubule


 This has a specialized part known as the Macula Dense that stimulates the production of renin in order to encourage the formation of aldosterone, so that the latter increases the reabsorption of sodium and water. In this way it increases blood pressure.

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