The proximal convoluted tubule (PCT) is a crucial part of the nephron, the functional unit of the kidney. Located after the Bowman’s capsule, the PCT is responsible for reabsorbing about 65-70% of the filtered water, sodium, and other essential nutrients back into the bloodstream. This process helps maintain the body's fluid and electrolyte balance. The PCT is lined with specialized cells that have microvilli, increasing the surface area for absorption. It also plays a role in secreting waste products and excess ions into the urine. Proper functioning of the PCT is vital for overall kidney health and efficient waste removal from the body.