Skeletal System

Bone Classification: By Shape

Long - Longer than wide (support mobility, energy storage blood cell)

Short - Cube shaped, stability, limit move, distribute

Flat - provide protection, broad surface, hematopoesis

Irregular - form = function

Sesamoid - pattela, protects tendons, ligaments, from wear and tear

Bone Tissue

Cortical Bone: Compact Bone

Trabecular bone: Spongy Bone

Microscopic Structure of Compact Bone

Osteons: Central Canal, Concentric Lamellae, Lacunae, Canaliculi

Perforating Canals

Compact: Rigid outter shell

Microscopic Structure of Spongy Bone

Trabeculae and red marrow spaces

Orientation along stress line

Spongy: Distritube forces equally reduces weight, support marrow

Bone is a Type of Connective Tissue

Cells

Gels

Fibers

Bone Cells

Osteoprogenitor cells: Stem cell can become osteoblast

Osteoblast: Build

Osteocytes

Osteoclasts: use enzymes and acids to breakdown bone

Red Bone Marrow

Function and regulation

Locations in Adults v Infrants

Yellow bone Marrow

Function and Composition

Locations in Adults v Infants

Yellow to Red Conversion

A patient undergoing chemotherapy develops sever anemia and fatigue. Blood tests show a drastic drop in all blood cell types. Which type of bone marrow is most likely affected, and why would chemotherapy case this condition?

Red bones marrow

Red marrow rapid growth

A mountain climber moves from sea level to 12,000 ft elevation for several months. Predcit what happens to the proportion of red and yellow marrow and explain why?

Yellow marrow convert to Red marrow

Red marrow goes up. Yellow Marrow goes down

Periosteum and Endosteum

Periosteum

Organization and composition

4 Functions

• Appositional growth

• Repair

• Attachment Site

• Protection

Do you think periosteum is thicker in adults or children?

Children because they still growth

Endosteum

Organization and composition

Function

• Bone remodeling

Comparison Table

Gross Anatomy of a Long Bone

Diaphysis, Epiphysis, Metaphysis

Medullary cavity, Articular Cartilage

Periosteum, Endosteum

Name two functions of the periosteum

Protection, repair

Which bone cell type is responsible for bone resorption?

Osteoclasts

The periosteum is thick and highly osteogenic in which age group?

Child

What type of bone marrow predominates in infants, and why?

Red because they need to growth

What type of bone marrow predominates in adults, and why?

Yellow to storage energy

The functional signigicance of the medullary cavity is to:

A: Strengthen compact bone

B: Reduce bone mass and store marrow

C: Anchor muscles

D: Provide attachment for ligaments

B: Reduce bone mass and store marrow

Remember when you were younger and you bumped your ankle with your scooter. Why does this cause suck immediate pain even though bone tissue itself isn’t hight innervated?

Periosteum is highly innvervated

In a growing child, why might the periosteum the thicker and more active than in an older adult, even before considering remodeling?

Children are still growth so their bones be thicker