SKELETAL SYSTEM:

BONES:

Cranium: top of skull

Mandible: jaw bone

Vertebrae: back bones

Clavicle: collar bone

Scapula: shoulder blade

Sternum: center of chest

Rib: self-explanatory

Pelvis: hip bone

Humerus: top of arm

Radius: thumb side of forearm

Ulna: outside of forearm

Femur: top of leg

Tibia: larger bone in lower leg

Fibula: smaller bone in lower leg

Patella: kneecap

Phalanges: fingers and toes

GENERAL:

Skeleton: All of the bones in an organism. Provides structure, support and protection.

Internal skeleton: located inside of body. Ex.: humans, vertebrates

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.