| A | B |
|---|
| anatomy | structure of an organism and its parts |
| physiology | study of functions or processes in an organism |
| tissue | cooperating unit of many similar cells that perform a specific function |
| organ | unit consisting of several tissues that together perform a specific task |
| organ system | unit of multiple organs that together perform a vital body function |
| epithelial tissue | sheets of closely packed cells that cover the surface of the body and line the internal organs |
| connective tissue | groups of cells that hold together and support other tissues and cushion, insulate, and connect organs |
| nervous tissue | tissue that transmits signals in the body in response to changes in the environment |
| neuron | nerve cell; basic unit of nervous tissue |
| skeletal muscle | voluntary muscle tissue attached to the skeleton that allows movement of the body |
| cardiac muscle | involuntary muscle tissue that causes the heart to pump blood |
| smooth muscle | involuntary muscle tissue found in most organs of the body |
| homeostasis | internal stability or "steady state" maintained by the body |
| hormone | signal molecule released into the bloodstream that triggers particular responses |
| interstitial fluid | aqueous solution that fills the gaps between cells in a tissue |
| integumentary system | outer covering that physically separates the body from the external environment |
| epidermis | outermost layer of skin |
| melanin | pigmented protein that gives skin its color |
| dermis | layer of skin beneath and supporting the epidermis, made up mostly of fibrous connective tissue that gives the skin its strength and elasticity |
| hypodermis | deepest layer of skin; contains adipose tissue, a connective tissue that includes fat-storing cells and blood vessels |
| vertebra | segment of the backbone; encloses and protects the nerve cord |
| cartilage | type of connective tissue softer than bone |
| marrow | specialized tissue found in bone |
| joint | area where one bone meets another |
| ligament | strong fibrous connective tissue that holds together the bones in movable joints |
| arthritis | skeletal disorder characterized by swollen joints |
| osterporosis | disorder in which bones become thinner, more porous, and more easily broken |
| tendon | dense connective tissue that attaches a muscle to a bone |
| muscle fiber | single, long cylindrical muscle cell containing many nuclei |
| myofibril | unit of muscle fiber made up of smaller units that contract (sarcomeres) |
| sarcomere | unit of contraction in a muscle fiber |
| actin | twisted, thin filament in a muscle fiber |
| myosin | thick filament in a muscle fiber; has bump-like projections |
