Does not contain microvilli, doesn't absorb
Things that we don't want but still have after filtration end up here for excretion (drugs, toxins)
Transport proteins, NKCC2s, are found here in the macula densa. It is a Na, K, 2Cl symporter into the cell.
Na/Cl symporters also found here, inhibited by thiazides
Hormone-regulated re-absorption of water happens here