Final answer:
Canaliculi are filled with tissue fluid that allows for the exchange of nutrients and waste products between osteocytes and blood vessels.
Step-by-step explanation:
Osteocytes are star-shaped cells found in bone tissue. These cells are connected to each other and to the central canal of an osteon through tiny canals called canaliculi. Canaliculi are filled with tissue fluid and **extend from the lacunae** where osteocytes are located. Apart from osteocytes, **canaliculi also contain tissue fluid**, which allows for the exchange of nutrients and waste products between osteocytes and blood vessels.