1. Ch 7 – Skeletal System
Notes

2. Components of the bones...
Bone tissue
Cartilage
Dense connective tissue
Blood
Nervous tissue

3. Functions of the bones... Attach to muscles
Protect and support softer tissues
House blood-producing cells
Store inorganic salts
Form passageways for blood vessels and nerves

4. Bone Classification Bones are classified according to shape:
Long bones
Short bones
Flat bones
Irregular bones
Sesamoid/Round bones

5. Parts of a Long Bone Examples: femur
On the ends: epihyses - forms a joint with another bone.
Proximal vs distal
Made of spongy bone
Covered by articular cartilage
Area between epiphyses: diaphysis
Made 0f compact bone
Covered by periosteum
Firmly attached
Continuous with ligaments and tendons
Helps form and repair bone tissue
Epiphysis; spongy bone; articular cartilage; diaphysis; compact bone; periosteum

6. Compact vs Spongy bone Pg 134 Fig 7.2 Compact Spongy bone
Continuous extracellular matrix with no spaces.
Spongy bone
Conatins trabeculae
Reduces bone’s weight
In the middle...
Medullary cavity
Lined by spongy bone
Filled by marrow
Trabeculae; weight;

7. Microscopic Structure
Bone cells are called osteocytes
Compact
They form circles of lacuna around central canal.
The circular shapes are osteons
Central canal contains blood vessels and nerves.
Spongy
No osteons

8. Development and Growth
Bone development starts within the first few weeks of conception.
Two ways bones form:
Intramembranous bones
Endochondral bones
Ossification – the formation of bone
Formation of a bone

9. Intramembranous Bones
Skull
First forms as connective tissue.
Progenitor cells become osteoblasts.
Forms spongy bone tissue in all directions.
Osteocytes on the outside form compact bone.
Connective tissue; osteoblasts; spongy; compact bone

10. Endochondral Bones Most bones Start as masses of hyaline cartilage
Steps
Six steps – pg. 136
Hyaline cartilage; diaphysis; periosteum; blood vessels, spongy; compact

11. Bone function Four main functions
Support/Protect – Give Shape; marrow and blood vessels; stores fat (yellow marrow)
Body Movement – attach muscles; act as levers
Blood Cell Formation – hematopoiesis; red marrow (RBCs, WBCs, platelets)
Storage of Inorganic Salts – Calcium; negative feedback mechanism

12. Quizzes over bones 7.1/7.3 – Bone structure 7.9 – Axial/Appendicular
7.10/7.12/7.13/7.14/7.15 – Skull
7.21 – Thoracic Cage

13. Journal 2/21
What is the difference in the axial and appendicular skeletons?
What kind of developmental bones become part of the skull?

14. Joints – Sec 7.13 Another word for joints is ______________.
Two forms of classification:
Movement
Immovable (synarthrotic), slightly movable (amphiarthrotic), or freely moveable (diarthrotic).
Type of tissue
Fibrous, Cartliaginous, or Synovial

15. Fibrous Joints Joints that closely contact one another
Layer of dense connective tissue in between
Generally immovable (synarthrotic)
Some have limited movement

16. Cartilaginous Joints Connected by hyaline cartilage
Absorbs shock and equalizes pressure
Limited movement (amphiarthrotic)

17. Synovial Joints Most joints in the skeletal system
Free movement (diarthrotic)
More complex
Hyaline cartilage, dense connective tissue
Contains synovial fluid
Some conatin menisci – flattened, shock-absorbing pads of fibrocartilage.
Some contain bursae – fluid- filled sacs
Six different categories