1. Transcellular Pathway: This pathway involves the movement of substances through the cell itself. It involves the following steps:

* Luminal membrane transport: The substance crosses the apical membrane of the tubular cell facing the lumen of the tubule. This can be via passive diffusion, facilitated diffusion, or active transport.

* Intracellular transport: The substance moves through the cytoplasm of the tubular cell.

* Basolateral membrane transport: The substance crosses the basolateral membrane of the tubular cell facing the interstitial fluid and blood vessels.

2. Paracellular Pathway: This pathway involves the movement of substances between the cells, through the tight junctions that connect adjacent tubular cells. This pathway is primarily for small, uncharged molecules.

3. Transcytosis: This pathway involves the movement of substances across the tubular cell via vesicles. This is a less common pathway than transcellular or paracellular transport, and is often used for larger molecules or those that need to be transported intact.

It's important to note that the specific pathway used for reabsorption depends on the substance being reabsorbed and the specific part of the nephron.