skeletal system written

Skeleton

The hard framework of bones that supports the body, protects organs, and allows movement

Bone

A hard connective tissue that forms the skeleton

Function of skeleton

Support, protection, movement, blood cell formation, mineral storage

Types of bones

Long bones, short bones, flat bones, irregular bones

Long bone

A bone longer than its width found in limbs

Example of long bone

Femur

Short bone

A cube-shaped bone providing stability

Example of short bone

Carpal bone

Flat bone

A thin bone that protects organs

Example of flat bone

Sternum

Irregular bone

A bone with complex shape

Example of irregular bone

Vertebra

Compact bone

The hard outer layer of bone

Spongy bone

Porous bone found at ends of long bones

Location of compact bone

Shaft of long bones

Location of spongy bone

Epiphysis and flat bones

Bone marrow

Soft tissue inside bones

Red bone marrow

Forms blood cells

Yellow bone marrow

Stores fat

Bone cell that builds bone

Osteoblast

Mature bone cell

Osteocyte

Bone cell that breaks bone

Osteoclast

Bone matrix

Rich in calcium salts

Function of calcium in bone

Gives hardness and strength

Structure of long bone

Diaphysis and epiphysis

Diaphysis

Shaft of long bone

Epiphysis

End of long bone

Epiphyseal plate

Site of bone growth in length

Medullary cavity

Cavity containing bone marrow

Osteon

Structural unit of compact bone

Haversian canal

Central canal of osteon

Blood cell formation site

Red bone marrow

Importance of skeleton in movement

Bones act as levers for muscles

Axial skeleton

Skull, vertebral column, rib cage

Appendicular skeleton

Limbs and girdles