Chapter 4 The Skeletal System 131 Know and Understand 1. List each of the five functions of the skeletal system and describe how they benefit the body. 2. Explain the differences between cortical bone and trabecular bone. 3. Describe where the diaphysis of a long bone is in relation to the epiphysis, and where the periosteum is in relation to the endosteum. 4. Briefly describe the process of remodeling. Analyze and Apply 5. Compare and contrast osteoblasts and osteoclasts and explain how they work together to reshape and remodel bones. 6. Explain why a physician might be worried about a child who broke a long bone close to the epiphyseal plate. 7. Keeping in mind the properties of cortical and trabecular bone tissue, describe the structure of a bone and why the two bone tissue types are found where they are in bones (outside or inside). 8. An elderly woman and her young granddaughter are involved in an automobile accident. The woman sustained several broken ribs, but her granddaughter did not have any injuries. In terms of bone mineralization, why might the older woman have sustained injuries, while her granddaughter did not? 9. Explain why someone whose job involves manual labor, such as construction, roofing, or carpentry, would have noticeably larger and stronger upper body bones than someone who has a different occupation. 10. Before reading further in this chapter, make labels for all the bones that you can name. Quickly research the bones identified on your labels. Taking turns with your classmates, place your labels on the correct bones of the classroom skeleton and tell what category (long, short, flat, sesamoid, irregular) each bone belongs to. 11. Draw or trace a cross-section picture of a long bone. Label the outside parts: epiphysis, diaphysis, and articular cartilage. Using different colors, draw and label the inside parts: trabecular bone, endosteum, yellow bone marrow, medullary cavity, and red marrow. On a separate piece of paper, describe each part that you have labeled. IN THE LAB Mini Glossary Make sure that you know the meaning of each key term. articular cartilage dense, white, connective tissue that covers the articulating surfaces of bones at joints bone marrow material with a rich blood supply found within the marrow cavity of long bones yellow marrow stores fat, and red marrow is active in producing blood cells cortical bone dense, solid bone that covers the outer surface of all bones and is the main form of bone tissue in the long bones diaphysis the shaft of a long bone endosteum membrane lining the medullary cavity epiphyseal plate growth plate near the ends of long bones where osteoblast activity increases bone length epiphysis the bulbous end of a long bone Haversian canals major passageways running in the direction of the length of long bones, providing paths for blood vessels Haversian system a single Haversian canal along with its multiple canaliculi, which branch out to join with lacunae, forming a comprehensive transportation matrix for supply of nutrients and removal of waste products also called an osteon hematopoiesis process of blood cell formation lacunae tiny cavities laid out in concentric circles around the Haversian canals medullary cavity central hollow in the long bones ossification process of bone formation osteoblasts specialized bone cells that build new bone tissue osteoclasts specialized bone cells that resorb bone tissue osteocytes mature bone cells osteon a Haversian system perforating (Volkmann’s) canals large canals that connect the Haversian canals also known as perforating canals oriented across bones and perpendicular to Haversian canals periosteum fibrous connective tissue membrane that surrounds and protects the shaft (diaphysis) of long bones remodeling process through which adult bone can change in density, strength, and sometimes shape trabecular bone interior, spongy bone with a porous, honeycomb structure LESSON 4.1 Review and Assessment Copyright Goodheart-Willcox Co., Inc.