1. SAP2b: Relate structure and function in skeletal system
Anatomy November 6th
Warm Up: Brief definition of these terms: pg 134: axial skeleton,
appendicular skeleton, compact bone, spongy bone,
Classwork: Introduction to skeletal system; color sheet bone structure
Closing: discussion of bone types

2. The Skeletal System
Chapter 6

3. System Functions: Support (bones, cartilage, ligaments)
Protection (ribs & skull)
Movement (muscle to bone by tendons)
Storage
Calcium & Phosphorus in bone
Adipose in Yellow Bone Marrow
Blood Cell Production
in Red Bone Marrow

5. Made of Connective Tissue with different substances in their Matrix:

6. Bone – collagen, calcium, phosphate
Cartilage – collagen & proteoglycans
Tendons – collagen (tough & ropelike)
Ligaments – collagen

7. Types of tissues
Collagen – common fibrous protein found in our bodies – makes up about 25% or more of the protein we have
Proteoglycans – carbohydrate and amino acid chains bound together

8. Bone Types:

9. Long Bones – longer than wide
ex. Ulna & Femur
Short Bones – long as they are wide
ex. Carpals & Tarsals
Flat Bones – thin & flat
ex. Scapula, ribs & skull bones
Irregular Bones – shape doesn’t fit other types
ex. Vertebrae & Facial Bones

10. Bone Structure/Contents:

11. Diaphysis – central shaft
Epiphysis – ends
Articular Cartilage – covers the Epiphyses

12. Medullary Cavity – spaces within the Diaphyses that contains Marrow
Red Marrow – forms blood cells
Yellow Marrow – adipose storage

13. Periosteum – dense connective tissue covering bone contains blood vessels & nerves

14. Endosteum – thinner connective tissue lining the Medullary Cavity

15. Osteoblasts – bone forming cells (they originate from the periosteum or from the bone marrow)
Osteoclasts – bone removing cells
Osteocytes – mature bone cells

16. Osteoclasts
Osteoblasts
Osteocytes

17. Lamellae – thin sheets of bone matrix
Lacunae – spaces in bone where osteocytes are located
Trabecular is synonymous with Cancellous or Spongy bone.

19. 2 Major Types of Bone Based on their Density:

20. 1.) Compact Bone – mostly solid (dense) cells
2.) Cancellous or
Spongy Bone -
A Lacy network of bone with small marrow filled spaces

21. Bone Formation/Growth

22. Ossification – Bone Formation
By Osteoblasts
A matrix of collagen and proteoglycans is laid down by the osteoblasts
Osteocytes form (this starts during fetal development & ends around yr of age)

23. Bone Growth in Length Composed of cartilage
Epiphyseal Plate also called the Growth Plate
Composed of cartilage
Found between the epiphysis & diaphysis
Growth occurs from this point.
When growth stops, the plate cartilage is replaced by bone and it is then called the Epiphyseal Line.

24. Bone Growth in Width
New bone lamellae (sheets of bone cells) are deposited onto existing bone
Osteoblasts are deposited onto new bone on top of the periosteum, which increases the width.

25. Bone Remodeling
Allows for bone to restructure and reshape itself to help to maintain bone strength
Existing bone removed by osteoclasts & deposition of new bone using osteoblasts

26. Incomplete & Closed Fracture Complete & Closed Fracture
Bone Fractures
Incomplete & Closed Fracture
Complete & Closed Fracture

27. Bone Fractures
Open Complete Fracture

28. Repair of Bone Fractures
Bones contain Nerves and Blood Vessels

29. What occurs in a broken bone…
damages blood vessels within
bleeding occurs & a clot forms
a fibrous network of connective tissue forms at the break – holding bone together
cartilage is added
this zone of tissue repair is called the Callus

30. Cancellous Bone is slowly remodeled to from Compact Bone
Continued….
Osteoblasts invade the Callus & forms cancellous bone – taking 4-6 weeks for completion
Cancellous Bone is slowly remodeled to from Compact Bone
Total healing time requires several months for normal bone strength to return

31. Bleeding & clotting occurs
Fibrous Connective Tissue & Cartilage is formed.
Compact bone eventually replaces cancellous bone.
Cancellous Bone forms.