1. Ch 6 SKELETAL SYSTEM
How many bones do you have in your body?

2. Label what you can

3. FUNCTIONS
1. SUPPORT– provides framework for body, support for soft tissues, attachment for tendons of skeletal muscles

4. FUNCTIONS
2. PROTECTION– of internal organs (brain, heart and lungs, spinal cord)

5. 3. LEVERAGE– muscles contract and pull on bones to provide movement
FUNCTIONS
3. LEVERAGE– muscles contract and pull on bones to provide movement

6. FUNCTIONS
4. MINERAL STORAGE– contribute to bone strength, stored calcium and phosphorus can be distributed to body at will (need Ca2+ for nerve impulses to cross synaptic cleft)

7. 5. BLOOD PRODUCTION– red marrow produces blood cells
FUNCTIONS
5. BLOOD PRODUCTION– red marrow produces blood cells

8. 6. ENERGY STORAGE– yellow marrow stores lipid (Energy reserve)
Functions
6. ENERGY STORAGE– yellow marrow stores lipid (Energy reserve)

9. Types of Bones
A. LONG BONES– longer than they are wide; curved; strong-absorb stress at several different points
EXAMPLES: femur, tibia, ulna, humerus, fingers, toes

10. Types of Bones B. SHORT BONES– as wide as they are tall;
EXAMPLES: wrist and ankle bones

11. TYPES OF BONES
TYPES OF Short bones
SESAMOID BONES – small; usually located in tendons (where there is a lot of physical stress) of hands, feet and knees; variable (#, ossification)
EXAMPLES: knee cap (everyone has)
fabella

12. TYPES OF BONES
C. FLAT BONES– thin spongy bone sandwiched between two layers of compact bone; protective; forms large surface area for muscle attachment; site of blood production in adults
EXAMPLES: cranial, sternum, rib, scapula, ilium

13. TYPES OF BONES D. IRREGULAR BONES– complex shapes
EXAMPLES: vertebrae, some facial bones, heel, ischium

14. TYPES OF BONES
E. SUTURAL BONES– small bones b/w joints of some cranial bones; variable (#)

15. HISTOLOGY (OSSEOUS TISSUE)
Composition:
1/3 COLLAGEN FIBERS (protein); function: FLEXIBILITY +
STRENGTH
2/3 MINERAL SALTS (mainly Ca & P); function : HARDNESS
Connective Tissue
Cells Matrix
Fibers Ground Substance

16. Histology (Osseous Tissue): Cell Types:
Osteoprogenitor (Osteogenic) Cells: stem cells (only bone cells that divide), precursors of osteoblasts
Osteoblasts: Bone building cells (secrete collagen; mineral salts deposited in collagen framework = calcification)
Osteocytes:– mature bone cells that maintain daily cellular activities of bone; most numerous
Osteoclasts: huge multinucleated cells; break down bone & allow for growth, maintenance & repair (lysosomal enzymes + acids digest protein & minerals = resorption (reg. Blood Ca2+)

18. Histology (Osseous Tissue): Cell Types:
Osteoprogenitor Cells  Osteoblasts  Osteocytes

19. What is the hardest substance in the body?

20. What spongy bone looks like. Video Links:
Short clip of Osteoblasts and Osteoclasts
Explanation of how bone is remodeled:

21. Bone Remodeling:
Rank Ligand:

22. LONG BONE GROSS ANATOMY (Ex: HUMERUS)
Each bone is an ORGAN With its own osseous tissue, cartilage, dense connective tissue, epithelial tissue, adipose tissue and nervous tissue

23. LONG BONE GROSS ANATOMY
DIAPHYSIS – long, main portion of bone (shaft)

24. LONG BONE GROSS ANATOMY
EPIPHYSIS – proximal and distal ends of bone (heads)

25. LONG BONE GROSS ANATOMY
METAPHYSIS – region where diaphysis meets epiphysis

26. LONG BONE
ARTICULAR CARTILAGE– thin layer of hyaline cartilage covering ends (epiphyses) of bones that contact other bones articulation/joint), reduces friction, absorbs freely moveable joints

27. LONG BONE GROSS ANATOMY
PERIOSTEUM– dense, white fibrous covering (dense irregular conn. tissue) around surface of bone – protects, nourishes, repairs, allows for growth, allows for attachment of tendons (& muscle) and ligaments

28. LONG BONE GROSS ANATOMY (Ex: HUMERUS)
PERIOSTEUM– dense, white fibrous covering
FIBROUS OUTER LAYER: OUTER LAYER: tendon (muscle) and ligament attachment and provides route for vascular and nervous tissue
2. CELLULAR INNER LAYER: growth & remodeling; osteoprogenitor cells, osteoblasts, & osteoclasts

29. LONG BONE GROSS ANATOMY

30. LONG BONE GROSS ANATOMY (Ex: HUMERUS
MEDULLARY CAVITY – cavity containing yellow marrow (fat cells – energy storage) in adults

31. LONG BONE GROSS ANATOMY (Ex: HUMERUS)
ENDOSTEUM – lining of medullary cavity containing osteoprogenitor cells, osteoblasts, & osteoclasts