The Skeletal System

Mini-Lecture One

The Skeleton• Word comes from the Greek Word meaning “dried-up” body.

2 subdivisions: • Axial• Appendicular

Components of the Skeletal System:

• 206 Bones

• Joints• Cartilage• Ligaments

Functions of Bone:

Support: Internal Framework of Body

Functions of Bone:

• Blood Cell Formation: (Hematopoiesis)–(hem’’ah-to-poi-e’sis)

Functions of Bone: • Protection: Protects soft body organs.

Functions of Bone:• Movement: Together with muscles they allow movement of the body.

• Storage–Fat–Minerals

•Calcium•Phosphorus

Functions of Bone:

Bones are Classified in Two Ways:

•By Tissue Type •By Shape

Bone Tissue• Compact:

–Dense–Looks “smooth”

• Spongy:–Small needlelike pieces of bone

–Lots of open space

Spongy bone

Compact bone

Shape of bones•Long•Short•Flat• Irregular

Long bonesMade up of

mostly compact bone

This is the traditional shape

of bone

Short bones Cube

Shaped

Mostly spongy bone

Flat Bones

•Thin

•Flat

•Usually Curved

• Examples: Skull, Ribs, Sternum

Compact with Spongy Bone

Irregular boneAll Other Bones

Examples: Vertebrae & Hip

Bones