The Skeletal System Part II Bone Development Osteogenesis

The Skeletal System Part II

Bone Development · Osteogenesis (ossification) = the process of bone tissue formation · In embryos this leads to the formation of the bony skeleton · In children and young adults, ossification occurs as part of bone growth · In adults, it occurs as part of bone remodeling and bone repair Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 12

Changes in the Human Skeleton · In embryos, the skeleton is primarily hyaline cartilage · During development, much of this cartilage is replaced by bone · Cartilage remains in isolated areas · Bridge of the nose · Parts of ribs · Joints Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 12

Bone Growth · Epiphyseal plates allow for growth of long bone during childhood · New cartilage is continuously formed · Older cartilage becomes ossified · Cartilage is broken down · Bone replaces cartilage Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 13 a

Bone Growth · Bones are remodeled and lengthened until growth stops · Bones change shape somewhat · Bones grow in width Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 13 b

Long Bone Formation and Growth Figure 5. 4 a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 14 a

Long Bone Formation and Growth Figure 5. 4 b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 14 b

Types of Bone Cells · Osteocytes · Mature bone cells · Osteoblasts · Bone-forming cells · Osteoclasts · Bone-destroying cells · Break down bone matrix for remodeling and release of calcium · Bone remodeling is a process by both osteoblasts and osteoclasts Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 15

Bone Remodeling and Modeling http: //youtu. be/0 d. V 1 Bwe 2 v 6 c

Bone Fractures · A break in a bone · Types of bone fractures · Closed (simple) fracture – break that does not penetrate the skin · Open (compound) fracture – broken bone penetrates through the skin · Bone fractures are treated by reduction and immobilization · Realignment of the bone Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 16

Bone Fractures

Common Types of Fractures

Compression Fractures

Depression Fracture

Compacted Fracture

Spiral Fracture

Greenstick Fracture

Repair of Bone Fractures · Hematoma (blood-filled swelling) is formed · Break is splinted by fibrocartilage to form a callus · Fibrocartilage callus is replaced by a bony callus · Bony callus is remodeled to form a permanent patch Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 18

Stages in the Healing of a Bone Fracture Figure 5. 5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5. 19

Anatomy of a Fracture • https: //www. youtube. com/watch? v=P 5 Hw. YWSh Bhw&list=UUDCWg. YMRq. AQL 8 uqghy 328 -g