Throughout life, bone is responsible for red and white blood cell production. Red bone marrow is the hemopoietic tissue of bone. Later in life, red bone marrow is replaced by yellow bone marrow, containing mostly fat cells. Thus, the body s ability to replace red blood cells, circulate oxygen, and prevent anemia is reduced as we age, similar to the reduction of bone density with age. Another term for a point of articulation is a joint.
Diarthroses are joints at which there is considerable movement.
If you look at diarthroses, they are connected by strong ligaments, or sheets of connective tissue composed of collagen. Between the two bones is a viscous synovial fluid surrounded by a synovial membrane, as well as articular cartilages that help to maintain the fluid movement of the joint. Tendons make connections between muscles and bone, a more cable-like connective tissue than ligaments. However, both tendons and ligaments act as binding structures for the skeletal system, and aid in resisting tension. When we go through the skeletal system for the next two lectures, we will be breaking it up into sections and discussing each section.