The nephron is the fundamental functional unit of the kidney, liable for the formation of urine.
Every human kidney has approximately 1,200,000 nephrons.
The function of the nephron is to filter elements from the blood plasma and eradicate undesirable waste by way of urine.
The nephron is the functional unit of the kidney. It produces concentrated urine by creating an ultrafiltrate from the blood. A nephron consists of two primary elements: a renal corpuscle and its related renal tubular system.
The renal corpuscles are positioned within the renal cortex, whereas their tubular systems prolong to the medulla. Relying on their distribution and morphology, there are two primary types of nephrons within the kidney: cortical and juxtamedullary.
The cortical nephrons have their corpuscles near the kidney capsule. Their tubules are very brief, extending only so far as the upper medulla. The corpuscles of the juxtamedullary nephrons are located near the corticomedullary boundary. Their tubular systems are for much longer, extending deep into the medulla.
Every nephron is surrounded by a network of capillaries. Branches of the renal interlobular arteries enter a nephron as an afferent arteriole, type a capillary tuft (glomerulus), after which exit the nephron as an efferent arteriole. The capillary network continues to encompass the renal tubular system of nephrons as peritubular capillaries, forming the vasa recta across the loop of Henle. Do you know that these peritubular capillaries secrete erythropoietin (EPO), a hormone that regulates red blood cell production?
Anatomy and Histology of the Nephron
The nephron is made up of the next parts:
- Renal corpuscle: at one end of the nephron, there’s the renal or glomerular capsule, the place the capillary glomerulus is situated inside.
- The renal capsule is a layer of epithelial cells that surrounds the glomerulus. The glomerulus is a tangle of blood capillaries. The renal capsule and glomerulus collectively form the renal corpuscle.
- Nephric tubule: the renal capsule connects to with the nephric tube. This has three distinct areas: the proximal convoluted tubule, the nephric loop or loop of Henle and the distal convoluted tubule, that flows into the collecting duct.
- Collecting Duct: responsible for conducting the urine produced to the ureter.
Urine Production
Urine is produced by way of three processes: filtration, reabsorption, and secretion.
Blood reaches the kidney by way of the renal artery and enters the capillaries of the glomerulus below high pressure.
This forces filtration within the glomerulus, with fluid leaving the renal capsule, forming the glomerular filtrate.
This filtrate contains water, urea, nutritional vitamins, amino acids, uric acid, salts, and so forth.
In the course of the passage of the glomerular filtrate by way of the proximal convoluted tubule, helpful substances are reabsorbed by the capillaries of the nephron. Alongside this path, greater than 99% of the water filtered within the glomerulus is reabsorbed.
On this method, water, glucose, amino acids, nutritional vitamins and a large a part of the salts from the glomerular filtrate return to the blood.
Within the nephric loop, water is reabsorbed from the glomerular filtrate into the capillaries.
Within the distal convoluted tubule, unwanted waste products from the blood capillaries are removed and launched into the urine. Examples of such waste products embody uric acid and ammonia. Lastly, the urine is released into the collecting duct and carried to the ureters.
