| A | B |
|---|
| skeletal system | internal framework of body |
| periosteum | tough outer membrane covering of bone |
| marrow | cavity in center of bones, makes blood cells |
| cartilage | smooth, thick layer of tissue between bones |
| joint | place where two bones meet |
| ligament | bone links bone |
| immovable joint | fixed, little or no movement |
| movable joint | allows movement |
| fracture | break in bone |
| biomaterials | artificial materials used to replace body parts |
| osteoporosis | disease that breaks down bone, causes it to become brittle and weak |
| muscle | organs that relax and contract, work in pairs |
| voluntary muscle | muscles that you are able to control |
| involuntary muscle | muscles that you can't control consciously |
| skeletal muscle | move bone, voluntary, striated |
| cardiac muscle | heart, striated, involuntary |
| smooth muscle | found in intestines, internal organs, nonstriated, involuntary |
| tendon | muscle to bone |
| epidermis | top layer, contains melanin |
| dermis | thick layer, contains nerves, glands and hair follicles |
| melanin | chemical that controls pigment |
