Final answer:
Blood/lymph vessels and nerves enter bone from the periosteum through nutrient foramina; blood vessels provide nourishment while nerves play roles in pain sensation, blood flow regulation, and bone growth.
Step-by-step explanation:
Blood and Nerve Supply to Bones
The periosteum is a fibrous membrane that covers the outer surface of bones, providing an entry point for blood/lymph vessels and nerves into the bone. These vessels and nerves enter through nutrient foramen, small openings found in the diaphysis. The periosteum itself contains blood vessels that penetrate into the spongy bone, nourishing the bone cells, or osteocytes. Blood flow continues through into the marrow cavities before being collected by veins, which exit the bone through the foramina.
In addition to providing nourishment, the nerves that enter the bone with the blood vessels perform crucial roles such as sensing pain, regulating blood supplies, and influencing bone growth, especially in metabolically active regions. These functions illustrate the interconnected nature of the skeletal and nervous systems.
The inner surface of the bone is lined with the endosteum, which is involved in bone growth, repair, and remodeling. The deep layers of the periosteum and the marrow are key sites for bone growth and development, with the periosteum serving as an attachment point for tendons and ligaments.