Chapter 4 The Skeletal System 167 er LESSON 4.4 Joints Key Points • The three main categories of joints, with regard to function, are the immovable joints (synarthroses), the slightly movable joints (amphiarthroses), and the freely movable joints (diarthroses). • Articular tissues include articular fibrocartilage, tendons, and ligaments. LESSON 4.5 Common Injuries and Disorders of the Skeletal System Key Points • Common bone injuries include fractures, or breaks, and epiphyseal injuries. • Osteoporosis is a condition in which bone mineralization and strength are critically low, often leading to fractures. • Sprains, dislocations, and bursitis are common joint injuries and disorders. • The signs and symptoms of arthritis include joint inflammation, pain, stiffness, and sometimes swelling. Key Terms amphiarthrosis articular fibrocartilage ball-and-socket joint bursae condyloid joint diarthrosis gliding joint hinge joint ligament pivot joint saddle joint symphysis synarthrosis synchondrosis syndesmosis synovial joint tendon tendon sheath Key Terms amenorrhea anorexia nervosa apophysis arthritis avulsion bulimia nervosa bursitis dislocation female athlete triad fracture osteoarthritis osteopenia osteoporosis rheumatoid arthritis sprain stress fracture Assessment 2. The term for blood cell formation is _____. A. osteocyte B. hematopoiesis C. osteogenesis D. osteoblast 3. The strong, dense type of bone tissue is called _____. A. trabecular bone B. coxal bone C. cortical bone D. hard bone LESSON 4.1 Bone as a Living Tissue Learning Key Terms and Concepts 1. The five functions of the skeletal system are blood cell formation, movement, support, storage, and _____. Copyright Goodheart-Willcox Co., Inc.