What materials are primarily retained by the glomerulus during blood filtration?

The glomerulus plays a crucial role as the filtration unit of the kidney, functioning to separate blood components based on size and charge. During this filtration process, it effectively retains larger molecules and cells while allowing smaller substances to pass through.

Proteins and red blood cells are primarily retained by the glomerulus. This is due to their relatively large size compared to the pores in the glomerular filtration membrane, which are designed to exclude these larger entities from entering the urine. In a healthy kidney, the filtration barrier prevents the passage of proteins, such as albumin, and blood cells, ensuring that they remain in circulation.

Other substances, such as water, ions, nutrients, glucose, and waste products, can pass through the glomerulus and enter the filtrate. However, the retention of proteins and red blood cells is a key function of the glomerulus in maintaining the composition of blood and preventing loss of vital components.