The functional unit of the proximal convoluted tubule
The functional unit of the proximal convoluted tubule (PCT) in the kidneys is called the nephron. The nephron is the basic structural and functional unit of the kidney responsible for the filtration, reabsorption, and secretion of various substances to maintain fluid balance and eliminate waste from the body.
Each nephron consists of a renal corpuscle, which includes the glomerulus and Bowman’s capsule, and a renal tubule. The renal tubule is further divided into several segments, including the proximal convoluted tubule.
The proximal convoluted tubule is the first segment of the renal tubule and is located closest to the renal corpuscle. It plays a vital role in the reabsorption of water, electrolytes, and nutrients from the filtrate produced in the glomerulus. This reabsorption process helps maintain the body’s fluid balance and reclaims essential substances that the body needs.
The PCT is characterized by its highly convoluted structure, which increases its surface area for reabsorption. It is lined with specialized epithelial cells that have microvilli on their apical surfaces, further increasing the surface area available for reabsorption.
Overall, the functional unit of the proximal convoluted tubule is the nephron, and specifically, the PCT plays a crucial role in the reabsorption of substances from the glomerular filtrate back into the bloodstream.