Chapter 5: The Skeletal System

1. List six functions of the skeleton.

a. Support b. Movement c. Protection d. Storage of minerals e. Fat storage f. Blood cell production
2. Compare compact and spongy bone. Compact bone is dense bone with very few spaces and is covered by a nourishing membrane called the periosteum. Spongy bone is identified by its many spaces that are filled with red bone marrow, which produces red blood cells.
3. Describe the structure of a long bone. Where are the yellow and red marrow found in adults? A long bone in the human body contains both compact bone and spongy bone. The compact bone is found on the outer surface of the bone and compose the shaft. The spongy bone is found at the ends of the long bone. Yellow bone marrow it found in the central shaft of the long bone surrounded by the compact bone. Red bone marrow is found in spaces of the spongy bone.
4. Describe the structure of an osteon, and explain the function of osteocytes and the central canal. The osteon consists of a central canal surrounded by concentric rings of osteocytes (mature bone cells) in a rigid matrix. O steocytes are located within a lacuna in the matrix. Canals connect the lacunae to each other and to the central canal. This allows for the transport of items between the cells and the blood vesels in the central canal.
5. Describe the formation of bone in a fetus. Explain how bone growth continues after birth. During fetal development, most of the skeleton is first formed of cartilage. Cartilage cells actively divide, allowing the skeleton to grow as the fetus does. Beginning around the third month of development, osteoblasts (bone-forming cells) form a ring of bone around the cartilage and create the shaft o the bone; the cartilage cells degenerate forming the center cavity of the bone. Osteoblasts then fill