1. Chapter 7 Skeletal System
*You may want to attach paper to your study guide for further room for writing

2. Aids to Understanding Words
Complete the Aids to Understanding Words
You may just write what is in the parentheses
You may also want to write “key words” or “clues”

3. Living Tissues of Bone Bone tissue Cartilage Dense connective tissue
Blood
Nervous tissue

4. Classifying Bones by Their Shape
Long bones – long longitudinal axes, expanded at each end
Thigh bones, forearms
Short bones – cubelike, lengths/widths equal
Wrists, ankles
Flat bones - platelike, broad surfaces
Ribs, scapula, bones of skull

5. Classifying Bones
Irregular bones – variety of shapes, usually connected to other bones
Vertebrae, facial bones
Sesamoid (round) bones – small and nodular, embedded within tendons (muscle to bone), adjacent to joints
Kneecap (patella)

6. Parts of a Long Bone
Use the worksheet provided to label these parts AND write their functions (p.132 Fig.7.1)
Epiphysis (proximal and distal)
Diaphysis
Periosteum
Compact bone
Spongy bone
Medullary Cavity
Red Marrow (spaces) *see sheet
Yellow Marrow *see sheet

7. Bone Structure and Function
Bones have projections called “processes” that provide attachment sites for ligaments and tendons
Some bones have small holes to allow passage of blood vessels and nerve fibers
Shape of bones helps them to fit together

8. Periosteum Vascular, fibrous tissue covering the bone
Function – formation and repair of bone tissue
Generally located on the diaphysis (shaft)

9. Compact Bone vs. Spongy Bone
continuous matrix with no gaps
typically form outer walls of long bones
Spongy
branching bony plates
irregular connecting spaces
lace-like appearance
found in hollow tube of compact bone (long bone)

10. Osteocytes Osteocytes – bone cells Found in lacunae (bony chambers)
Form concentric circles around the central canal
Look at page 108 to refresh your memory
*cellular matrix of bone is composed of collagen (resilience) and calcium phosphate (hardness)

11. Flashcard Time!
Use the notecards provided to make flashcards for the following:
Long bones *
Short bones *
Flat bones *
Irregular bones *
Sesamoid bones *
*also list examples with the description

12. Flashcards Continued! Epiphysis Diaphysis Compact bone Spongy bone
Medullary cavity
Worth 10 points - due by the end of class!

13. Bone Development/Growth: Intramembranous Bone
Broad, flat bones of skull - form during first weeks of embryonic development
Membrane-like layers appear at future bone sites
Tissues enlarge to form osteoblasts
Osteoblasts deposit bony matrix  spongy bone  periosteum  compact bone (between periostem and spongy)
Ossification – formation of bone

14. Bone Development/Growth: Endochondral Bones
Most of the bones of the body – develop in fetus from masses of hyaline cartilage
Models of cartilage grow rapidly and then begin to change
Long bones - cartilage breaks down and disappears
Periosteum forms  encircles diaphysis  blood vessels and osteoblasts form spongy bone

15. Ossification of Endochondral Bones
Primary Ossification Center (diaphysis)
first region of bone formation, development proceeds to ends of bone
Secondary Ossification Center (epiphysis)
Spongy bone forms in all directions
Epiphyseal plate (cartilage) remains between centers

16. Epiphyseal Plate
Epiphyseal plate contains dividing cells that lengthen the bone
When the centers meet and the plate ossifies – lengthening is no longer possible
Look at page 134, Fig. 7.5
What happens if the plate is damaged before it ossifies?

17. Ossification Complete when adult size is reached
Homeostasis of bone tissue
Life long process of bone remodeling
Osteoclasts (cells that erode bone) reabsorb bone matrix
Osteoblasts (bone-forming cells) replace bone matrix
Hormones that control blood calcium help control the resorption and deposition (3-5% exchanged of bone calcium exchanged each year)

18. How is a fracture healed? Pages 136 - 137
Blood vessels rupture, and periosteum tears
Blood spreads and develops a hematoma (blood clot)
Vessels in surrounding tissues dilate – causing swelling and inflammation
Osteoblasts and new blood vessles invade the hematoma and form spongy bone

19. Fracture Healing ( continued)
Fibroblasts farther from a blood supply produce masses of fibrocartilage
Phagocytes and osteoclasts remove the hematoma and other bone debris
Fibrocartilage fills the gap between the ends of the broken bone
The cartilaginous callus is replaced by bone tissue
Phew! Smaller the fracture, faster the healing.

20. Factors Affecting Bone Growth/Development
Nutrition
Vitamin D for proper absorption of Calcium
Hormonal secretions
Growth hormones stimulate cell division
Sex hormones stimulate ossification of ephiphyseal plates (Why sex hormones?)
Physical exercise
Provides stress needed to thicken and strengthen bones

21. Book Work! Page 171, Chapter Assessments #s 1-8
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