What process describes the passage of water and solutes into the nephron?

The process that describes the passage of water and solutes into the nephron is filtration. This occurs primarily in the glomerulus, a network of capillaries located at the beginning of the nephron. During filtration, blood pressure forces water, electrolytes, and small molecules, such as glucose and urea, through the walls of the glomerulus and into the Bowman’s capsule, a cup-like structure surrounding the glomerulus. This creates a filtrate that contains many of the same constituents as plasma, minus the larger components like proteins and red blood cells.

Filtration is a critical first step in the process of urine formation, directly influencing the body’s fluid and electrolyte balance. Once the filtrate has been formed, it undergoes further processing where some substances are reabsorbed back into the bloodstream, while others may be secreted into the nephron for excretion, but these actions come after the initial filtration process has occurred.