JUXTAMEDULLARY NEPHRON Meaning and
Definition
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A juxtamedullary nephron is a specialized component of the kidney responsible for the filtration, reabsorption, and secretion of various substances in the body. It constitutes around 15% of the total nephrons present in each kidney.
The term "juxtamedullary" refers to the location of these nephrons, which are positioned adjacent to the renal medulla (innermost part of the kidney). This proximity plays a crucial role in their unique functionality.
Juxtamedullary nephrons have a long loop of Henle, a U-shaped structure that extends deep into the renal medulla. This loop allows for effective water conservation and concentration of urine. The descending limb of the loop is permeable to water, enabling the reabsorption of water into the bloodstream, while the ascending limb is primarily responsible for transporting electrolytes out of the tubules.
In addition to their extended loop of Henle, juxtamedullary nephrons possess specialized cells called juxtaglomerular cells. These cells are located in the wall of the afferent arteriole, which supplies blood to the glomerulus (a network of capillaries where filtration occurs). Juxtaglomerular cells produce and release the enzyme renin, which plays a vital role in regulating blood pressure and fluid balance.
Overall, juxtamedullary nephrons are integral components of the kidney's intricate filtration and reabsorption processes, ensuring the maintenance of proper electrolyte balance and efficient water conservation in the body.
Etymology of JUXTAMEDULLARY NEPHRON
The word "juxtamedullary nephron" is composed of two main elements: "juxta" and "medullary".
The term "juxta" is derived from the Latin word "juxta", meaning "near" or "beside". This element is often used in biological terms to indicate something that is situated close to or next to another structure.
The term "medullary" is derived from the Latin word "medullaris", meaning "marrow" or "middle". In the context of the nephron, it refers to the medulla, which is the inner part of an organ or structure.
Therefore, when combined, "juxtamedullary nephron" refers to a type of nephron that is located near or beside the medulla of the kidney.
