Nephron Definition

“Nephron is the simple functional unit of kidney that consists of a glomerulus and also its connected tubules v which the glomerular filtrate passes prior to it emerges as urine”

Let’s go through the structure and role of the nephron and learn much more in detail about the different parts that the nephron and the function of renal tubule in to pee formation and excretion process.

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A nephron is the basic structural and functional unit that the kidney. They are the microscopic structure composed of a renal corpuscle and a renal tubule. The word nephron is acquired from the Greek native – nephros, definition kidney. There are about millions the nephrons in each person kidney.


Structure of Nephron

The mammalian nephron is a long tube-like structure, its size varying native 35–55 mm long. In ~ one end, the tube is closed, folded and expanded, right into a double-walled, a cuplike structure dubbed the Bowman’s capsule or renal corpuscular capsule, which encloses a cluster of microscopic blood vessels called the glomerulus. This capsule and glomerulus with each other constitute the renal corpuscle.

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The structure of nephron comprises two major portions:

Renal TubuleRenal Corpuscle

Renal Tubule

The renal tubule is a long and convoluted structure that emerges from the glomerulus and also can be divided into three parts based on function.

The very first part is dubbed the proximal convoluted tubule (PCT) due to its proximity come the glomerulus; it stays in the renal cortex.The second part is called the loop the Henle, or nephritic loop because it forms a loop (with descending and ascending limbs) the goes v the renal medulla.The third part of the renal tubule is called the distal convoluted tubule (DCT) and this part is also minimal to the renal cortex.

The capillaries that the glomerulus space enclosed through a cup-like structure called Bowman’s capsule. This framework extends to kind highly coiled tubules called PCT. PCT proceeds to form the loop the Henle which ascends to DCT, which in turn opens right into the collecting duct.

The major function that tubules is reabsorption and the procedure can one of two people be v active transport or passive transport. In addition, secretions by tubules help in the urine formation without affecting the electrolyte balance that the body.

Proximal Convoluted Tubule (PCT)

The blood brought by the renal artery is filtered by the glomerulus and also then passed to the PCT. Maximum reabsorption takes location in PCT of the nephron.PCT is the region of renal tubule where reabsorption of essential substances choose glucose, proteins, amino acids, a major portion the electrolytes and water take away place. The surface area because that reabsorption is helped with by the lining that the straightforward cuboidal epithelium in them. Reabsorption takes place at the cost of energy, i.e., the process is active.PCT selectively secretes ions such together hydrogen, ammonia, and also potassium into the filtrate and absorbs HCO3–from it. Thus, PCT maintains the electrolyte and acid-base balance the the human body fluids.

Henle’s Loop

Henle’s loop has actually a descending and also an ascending limb. Being parts of the very same loop, both the descending and also ascending limbs show different permeability. The descending limb is permeable to water yet impermeable to an electrolyte, if the ascending limb is permeable to electrolytes however impermeable come water. Because the electrolytes acquire reabsorbed at the ascending loop of Henle, the filtrate it s okay diluted together it moves in the direction of the ascending limb. Yet reabsorption is limited in this segment.

Distal Convoluted Tubule (DCT)

The DCT, i m sorry is the last component of the nephron, connects and empties its contents into collecting ducts that line the medullary pyramids. The collecting ducts amass materials from lot of nephrons and also fuse with each other as they get in the papillae the the renal medulla.

Similar come PCT, DCT additionally secretes ion such together hydrogen, potassium, and also NH3 into the filtrate while reabsorbing the HCO3–from the filtrate. Conditional reabsorption of sodium ions and water takes place in DCT. Thus, the maintains the pH and sodium-potassium level in the blood cells.

Collecting Duct

Collecting duct is a long, right tube where H+ and K+ ions space secreted to maintain the electrolyte balance that the blood. This is additionally the region where the preferably reabsorption the water takes place to produce focused urine.

Renal Corpuscle

The renal corpuscle is composed of a glomerulus surrounded by a Bowman’s capsule. The glomerulus arises from an afferent arteriole and also empties right into an efferent arteriole. The smaller diameter of an efferent arteriole helps to keep high blood pressure in the glomerulus.

The Bowman’s capsule is divided into three layers:

Outer Parietal layer: It is consisted of of epithelial cells with minute pores of diameter 12nm.Middle Basement membrane: This layer is selectively permeable.Inner Visceral Layer: It consists of large nucleated cells dubbed podocytes which be affected by each other finger-like projections referred to as podocel.

Also Read: Human Excretory System


There space two types of nephron:

Cortical nephron

These are the nephrons present within the cortex. These are short and comprise about 80% the the full nephrons.

Juxtamedullary nephron

These have long loops the Henle and also extend right into the medulla. These are about 20%.


The primary function of nephron is removing every waste commodities including the solid wastes, and also other overfill water from the blood, converting blood right into the urine, reabsorption, secretion, and also excretion of many substances.

As the blood passes v the glomerulus with high pressure, the little molecules are moved into the glomerular capsules and travel v a winding collection of tubules.

The cell present in each pipe absorbs various molecules not included the glucose, water, and also other valuable molecules which are dubbed as the ultrafiltrate. As the ultrafiltrate molecules travel down the tubules they become more and more hypertonic, which results in more amount the water come be extracted from the ultrafiltrate prior to it exit the nephrons.

The blood neighboring the nephron travels ago into the body through the renal blood vessels, i beg your pardon are cost-free of toxins and also other overfill substances. The acquired ultrafiltrate is urine, which travels under via the collecting duct come the bladder, whereby it will be stored and released with the urethra.

Also Read: Urine Formation and Osmoregulation


Though excretion in people takes location through lungs, skin, liver, the kidneys room the main organs the the human excretory system. They are bean-shaped organs, i m sorry weigh between 150 to 170 gms and also their size ranges from 4 – 5 inches long.

The kidneys are situated in the retroperitoneal space in the abdominal cavity, just below the rib cage and present in the opposite direction or encountering each other on both the left and also right next of the body. The appropriate kidney is contempt smaller and also lower 보다 the left kidney.

Compared to males, the total area, size and also the load of the kidneys are smaller sized in females. Therefore, both male and female need to be mindful during their kidney transplantation.

 The major functions the the kidneys are to:

Maintains the body’s pHReabsorption of nutrientsRegulates blood pressureExcretion of wastes indigenous the bodyRemoval that excess liquid from the bodySecret hormones that aid in the manufacturing of red blood cell, acid regulation, etc.

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The sensible unit of the kidney is the nephron. Each kidney is composed of millions of nephron which plays a significant role in the filtration and also purification of blood. The nephron is divided into 2 portions, namely, the glomerulus and the renal tubule and helps in the removed of overfill waste from the body.

Also Read: Regulation the Kidney Function

Learn more about Nephron, its structure, function, renal tubule, renal corpuscles and other connected topics at BYJU’S Biology