Skeletal System

Parts of the skeletal system

bones(skeleton)
joints
cartilage
ligaments

divided into 2 divisions

axial
appendicular

axial skeleton

head ribcage spine

appendicular skeleton

arms legs hips shoulders

functions of bones

supports the body
protects soft parts
movement
storage of minerals and fats
blood cell formation(hematopoeisis)

bones of the human body

the skeleton has 206 bones

two types of bone

compact bone
spongy bone

compact bone

homogeneous

spongy bone

small needle like pieces of bone
many open spaces

classification of bones

long bones
short bones
flat bones
irregular bones

long bones

typically longer than wide
have a shaft with heads at both ends
contain mostly compact bone
femur, humerus

short bones

mostly cube-shaped
comprised of spongy bone
wrist carpals, ankle tarsals

flat bones

this and flattened
usually curved
thin layers of compact bone around a layer of spongy bone
skull ribs sternum

irregular bones

irregular shape
do not fit into other bone classification categories
vertebrae and hip bones

long bone

diaphysis
epiphysis
periosteum
sharpey's fibers
arteries
articular cartilage
medullary cavity

diaphysis

aka:shaft
composed of: compact bone

epiphysis

aka: ends of the bone
composed mostly of: spongy bone

periosteum

outside covering of the diaphysis
fibrous connective tissue membranes

sharpy's fibers

secure periosteum to underlying bone

arteries

supply the bone cells with nutrients

articular cartilage

covers the external surfaces of the epiphyses
made of hyaline cartilage
decreases friction at joint surfaces

medullary cavity

cavity of the shaft(marrow)
contains yellow marrow (mostly fat) in adults
contains red marrow (for blood cell formation) in infants