Final answer:
The outer portion of the periosteum is made of a fibrous membrane. It covers the entire outer surface of bone and contains blood vessels, nerves, and lymphatic vessels that nourish the compact bone.
Step-by-step explanation:
The outer portion of the periosteum is made of a fibrous membrane. The periosteum covers the entire outer surface of bone and contains blood vessels, nerves, and lymphatic vessels that nourish the compact bone. Tendons and ligaments also attach to bones at the periosteum.