The skeleton Flashcards
How many bones in the skeleton
206, light only 14% of body weight
what is the axial skeleton
Bones of skull, spine, & rib cage (80 bones)
what is appendicular skeleton
Bones of limbs and supporting girdles (shoulder girdle & pelvic girdle) 126 bones
what are the first 3 functions of bones
Structural Support - provides internal framework for body
Protection - vital organs of thorax, spinal cord, brain, etc.
Blood Cell and Platelet Formation - occurs within bone marrow cavities of certain bones
what are the 4th and 5th functions of bones
- Reservoir of Minerals (most important are calcium & phosphorus) - hormones control the movement of calcium and phosphorus to and from bones according to needs of body
Movement - attachment of muscles by tendons (muscles use bones as levers to move body parts)
what are long bones
Longer than they are wide
has a shaft and two ends
found in arms & legs
what are short bones
Usually cube-shaped (length, width, & height about the same)
Found in wrist and ankles
what are flat bones
Thin, flattened, and usually curved
Often protect vital organs
Most bones of skull, ribs and sternum
what are irregular bones
Odd looking bones that don’t fit into other categories
Vertebrae
what are sesamoid bones
Unusual bones, in that they are flat, small bones that are wrapped within tendons and move over bony surfaces
Patella
what is the use of bone markings
All bones have various markings (eg. projections, lines, holes, etc.) that serve as: attachment sites for tendons or ligaments, passageways for nerves and blood vessels, or points of articulation with other bones.
