| A | B |
|---|
| Skeleton | All of the bones in an organism. Provides structure |
| Internal skeleton | Located inside of body. Ex.: humans |
| External skeleton | Also known as exoskeleton. Hard outer covering that provides structure, support, protection. Ex.: insects, lobsters |
| Joint | Area where two bones meet. Most provide for movement; include fluid for lubrication and cartilage for protection. Ligaments hold bones together. |
| Cartilage | Smooth, slippery substance. Provides cushion, protection for bones in joints; prevents the bones from wearing against each other. Provides some structure in nose and ear. Provides flexibility in ribcage. |
| Ligament | strong connective tissue fibers that hold bones together |
| Tendon | strong connective tissue fibers that hold muscle to bone |
| Fluid | Thick, slippery liquid that provides lubrication in joints |
| Skeletal system | All of the bones in the body, together with the ligaments and cartilage |
| Outer covering | Thin, tough, smooth layer around outside of bone. Provides protection and attachment point for muscles |
| Compact bone | Solid, dense layer around outer surfaces of bones |
| Spongy bone | Highly porous regions of bone inside layer of compact bone; observed in ends of long bones (femur, etc.) and inside flat bones, like ribs. Holes are filled with fat cells, marrow, etc. Spongy bone is porous, but not squishy like a sponge! |
| Marrow | Squishy, fatty tissue found in centers of long bones. Primary site of blood cell production |
| Rickets | Bone disease resulting in weak or misshapen bones. Caused by vitamin D deficiency – insufficient exposure to sunlight |
| amphiarthrosis | A slightly movable joint, such as the joint joining the two pubic bones. |
| appendicular skeleton | The bones of the upper and lower extremities of the bodyarticular cartilage: cartilage covering the joint ends of bones. |
| axial skeleton | the bones of the head neck and torso. |
