What does the material that leaves the blood and enters the nephron make up?

The material that leaves the blood and enters the nephron primarily consists of water, electrolytes, waste products (such as urea and creatinine), and other small molecules. This process occurs during filtration in the glomerulus, where blood plasma is filtered through a semipermeable membrane. The filtered fluid, known as filtrate, then travels through various segments of the nephron, where further reabsorption and secretion occur, ultimately leading to the formation of urine.