On a giant pasteboard with pictures, and explanation on what each type of engineer.
Peeing in a cup is required for a drug test
Answer:
These are needed to mimic the blood vessels which these organs will use for the supply or drainage of fluids e.g blood.
In addition the empty tunnels serve as the routes for nutrients and oxygen supply for the organ.
In summary the tunnels provided a vascular structure to support the organ
Explanation:
Appositional growth is the term for the rise in diameter. The periosteum's osteoblasts build compact bone around the exterior bone surface.
