Nephrons are basic structural and functional units of the kidney. A human kidney’s number of nephrons ranges from 8 lacks to 1 crore.
Nephrons can be distinguished into Cortical and Juxtamedullary based on their location of the Malpighian corpuscles and the length of the loop of Henle.
Key Takeaways
- Cortical nephrons are located primarily in the renal cortex and makeup about 85% of nephrons in the human kidney.
- Juxtamedullary nephrons have their renal corpuscles close to the medulla, and their loops of Henle extend deep into the inner medulla, playing a vital role in urine concentration.
- Both nephrons are essential for kidney function and filtration, but they differ in their location within the kidney and their specific roles in urine production.
Cortical vs Juxtamedullary Nephrons
The difference between Cortical and Juxtamedullary nephrons is that cortical nephrons. Malpighian corpuscles are located in the outer cortex. In contrast, Juxtamedullary nephron Malpighian corpuscles are located under the base of pyramids.
Also, in cortical nephrons, the loop of Henle is short, while in Juxtamedullary nephrons, the loop of Henle is long. About 85% of the human kidney is made up of cortical nephrons, and about 15% is made up of Juxtamedullary nephrons.
The main function of cortical nephrons is to carry out the human body’s major regulatory and excretory functions. The main function of the Juxtamedullary nephrons is to concentrate or dilute urine.
Comparison Table
| Parameters of Comparison | Cortical Nephrons | Juxtamedullary Nephrons |
|---|---|---|
| Definition | Cortical nephrons are microscopic structural and functional kidney units with a short loop of Henle. | Juxtamedullary nephrons are microscopic structural and functional kidney units with a long loop of Henle. |
| Loop of Henle | They have a short loop of Henle and only penetrate the outer renal medulla. | They have a long Henle loop extending deep into the renal medulla. |
| Malpighian Corpuscles | Their Malpighian corpuscles are located in the outer parts of the renal cortex. | Their Malpighian corpuscles are located close to the renal medulla. |
| Occurrence | Cortical nephrons are about 85% of all the nephrons in the human kidney. | Juxtamedullary nephrons are about 15% out of all the nephrons in the human kidney. |
| Function | These nephrons carry out a central part of the regulatory and excretory functions in the human body. | These nephrons concentrate or dilute the urine in the human body. |
What is Cortical Nephrons?
Cortical nephrons are microscopic structural and functional kidney units with a short loop of Henle that only penetrates the outer renal medulla. Their Malpighian corpuscles are located in the outer parts of the renal cortex.
Cortical nephrons occur in all vertebrates. They carry out the central part of the regulatory and excretory functions in the human body.
A small network of capillaries, glomerulus, is located at the beginning of every cortical nephron in the outer renal cortex. The glomerulus filters the blood from the afferent arteriole of the renal arterial circulation.
Water, ions, amino acids, glucose, and other small molecules are filtered during filtration. Red blood cells, white blood cells, large proteins and platelets remain inside the glomerulus.
The others flow to the renal calyx as urine. A vascular network around Henle’s loop called the Vasa recta reabsorbs most of the water, ions, amino acids and glucose.
What is Juxtamedullary Nephrons?
Juxtamedullary nephrons are microscopic structural and functional kidney units with a long loop of Henle that extends deep into the renal medulla. Their Malpighian corpuscles are located close to the renal medulla.
Juxtamedullary nephrons only occur in birds and mammals. They make up 15% of all nephrons in the human kidney.
A large glomerulus is situated at the very beginning of each Juxtamedullary nephron.
The filtration rate of these nephrons is directly proportional to the size of their glomerulus. The bigger the size of the glomerulus, more is the rate of filtration.
A large Vasa recta network surrounds the long loop of Henle in these nephrons.
The generation of a hyperosmolar gradient leads to the production of concentrated urine. The main function of the Juxtamedullary nephrons is to concentrate or dilute urine in the body.
The urine concentration depends on the quantity of water the Vasa recta absorbs. If more water is absorbed, the urine will be more concentrated.
If less water is absorbed, the urine will be more diluted.
Main Differences Between Cortical and Juxtamedullary Nephrons
- Cortical nephrons are microscopic structural and functional kidney units with a short loop of Henle. In contrast, Juxtamedullary nephrons are microscopic structural and functional kidney units with a long loop of Henle.
- Cortical nephrons have a short loop of Henle and only penetrate the outer renal medulla. In contrast, Juxtamedullary nephrons have a long loop of Henle extending deep into the renal medulla.
- The cortical nephron’s Malpighian corpuscles are located in the outer parts of the renal cortex, while the Juxtamedullary nephron’s Malpighian corpuscles are located close to the renal medulla.
- Cortical nephrons are about 85% of all nephrons, whereas Juxtamedullary nephrons are about 15% in the human kidney.
- Cortical nephrons carry out the most significant parts of the regulatory and excretory functions, while Juxtamedullary nephrons concentrate or dilute the urine in the human body.
- In the Cortical nephron, the size of the glomerulus and Vasa recta are small, whereas, in the Juxtamedullary nephron, the size of the glomerulus and Vasa recta are large.
- https://journals.physiology.org/doi/abs/10.1152/ajprenal.1984.246.3.f349
- https://www.jci.org/articles/view/107663/files/pdf
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