Final answer:
Podocytes are the cells with long, interlacing foot processes called pedicels that form filtration slits in the filtration membrane of Bowman's capsule in the kidney.
Step-by-step explanation:
The cells within the filtration membrane that have long, interlacing foot processes are called podocytes. These cells form the visceral layer of Bowman's capsule. The extensions, known as pedicels, on one podocyte interdigitate with those of another podocyte, therefore contributing to the filtration membrane structure. These pedicels are crucial in forming filtration slits through which substances are filtered based on size and electric charge.
The filtration membrane also includes fenestrations in the capillary endothelial cells and the basement membrane, which together with podocytes, help to regulate the filtration process. This structure allows for the creation of a filtrate that is free from cells and large proteins, favoring the passage of substances with a small size (< 4 nm) and, to an extent, positively charged substances.