1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Biology Sylvia S. Mader Michael Windelspecht Chapter 11 Skeletal System Lecture Outline Part 3

2 Skeletal remains Characteristics to be determined –Age is approximated through dentition, studying areas of bone ossification, and joint condition. –For gender, it is best to use the pelvic bone, but the thickness of long bones or skull characteristics may also be used. –Ethnicity is difficult to tell, but skull characteristics are most useful Bones of the Appendicular Skeleton

3 Types of joints (where bones meet bones) __________ – usually immovable such as the sutures between cranial bones ______________ – tend to be slightly movable such as the intervertebral disks __________ – freely movable joints such as the ball-and-socket hip and shoulder joints, and the hinge knee and elbow joints 11.4 Articulations

4 Anatomy of a synovial joint 11.4 Articulations Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: © Gerard Vandystadt/Photo Researchers, Inc. a. A gymnast depends on flexible joints.d. Hinge joint ulna humerus c. Ball-and-socket joint scapulahead of humerus b. Generalized synovial joint ligament meniscus joint cavity filled with synovial fluid bursae articular cartilage meniscus ligament Figure 11.9 The structure of a synovial joint.

5 Summary of synovial joints movements Flexion – __________ in joint angle Extension – _________ in joint angle __________ – body part moves toward midline __________ – body part moves away from midline 11.4 Articulations

6 Summary of synovial joints movements Rotation – body part moves around its own axis Supination – hand faces anterior or downward Pronation – hand faces posterior or downward Circumduction – body part moves so that a cone shape is outlined 11.4 Articulations

7 Summary of synovial joints movements Inversion – sole of foot turns inward Eversion – sole of foot turns outward 11.4 Articulations

8 Visualizing synovial joints movements 11.4 Articulations Figure Synovial joints allow for a variety of movement. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. extension flexion extension abduction adduction abduction Rotation: Body part moves around its own axis. adduction extension abduction adduction Inversion: Sole of foot turns inward. Eversion: Sole of foot turns outward. Circumduction: Body part moves so that a cone shape is outlined. d.c. Supination: Hand faces anterior or downward. Pronation: Hand faces posterior or downward. Abduction: Body part moves away from midline. Adduction: Body part moves toward midline. b. Extension: Joint angle increases. Flexion: Joint angle decreases. a.

9 What are the important cells in bone growth, remodeling, and repair? Osteoblasts – bone-forming cells Osteocytes – mature bone cells that maintain bone structure derived from osteoblasts Osteoclasts – bone-absorbing cells Chondroytes – cartilage-forming cells 11.5 Bone Growth and Homeostasis

10 How does bone develop? Ossification is the formation of bone in 2 distinct ways. : 1._____________________ – bone development between sheets of fibrous connective tissue; used in flat bones 2._____________________ – cartilage is replaced by bone; used by most bones 11.5 Bone Growth and Homeostasis