| A | B |
|---|
| homeostasis | maintaining a stable internal environment |
| tissue | a group of cells working together |
| organ | a group of tissues working together |
| organ system | a group of organs working together |
| hinge joint | elbow or knee |
| ball and socket joint | shoulder or hip |
| gliding joint | ankle or wrist |
| voluntary muscles | we control the muscle movement |
| involuntary muscles | we do not control the muscle movements |
| flexor | biceps |
| extensor | triceps |
| melanin | protects skin from harmful UV rays from the sun |
| hair | provides protection and warmth; dead except in follicle |
| dermis | lower layer of skin; contains living cells |
| epidermis | outer layer of skin; dead skin cells |
| chemical digestion | enzymes break down food |
| mechanical digestion | physically (mashing & grinding) break down food |
| veins | carry blood into the heart |
| arteries | carry blood away from the heart |
| capillaries | exchange of oxygen and carbon dioxide occurs here; very thin walls |
| nose | main passageway into respiratory system |
| pharynx | throat; leads to larynx and esophagus |
| larynx | contains vocal chords |
| trachea | windpipe |
| alveoli | where exchange of oxygen and carbon dioxide occurs inside the lungs |
