Final answer:
The blood vessel that runs down the middle of a Haversian system provides oxygen, nutrients, and waste removal to the bone cells.
Step-by-step explanation:
The blood vessel that runs down the middle of a Haversian system, known as a central canal or Haversian canal, provides oxygen, nutrients, and removes waste from the bone cells.
This network of blood vessels supplies necessary substances to the bone cells, such as oxygen and nutrients, for their survival and proper functioning. It also helps remove waste products, like carbon dioxide, from the bone cells.