maintenance of boundaries
keeps the body's internal environment distinct from the external environment
reproduction
provides new cells for growth and repair
growth
occurs when constructive activities occur at a faster rate than destructive activities
digestion
the tuna sandwich you have just eaten is broken down to its chemical building blocks
excretion
elimination of carbon dioxide by the lungs and elimination of nitrogenous wastes by the kidneys
responsiveness
ability to react to stimuli; a major role of the nervous system
movement
walking, throwing a ball, riding a bicycle
metabolism
all chemical reactions occurring in the body
maintenance of boundaries
at the cellular level, membranes; for the whole organism, the skin
nutrients
includes carbohydrates, proteins, fats, and minerals
atmospheric pressure
essential for normal operation of the respiratory system and breathing
water
single substance accounting for over 60% of body weight
oxygen
required for the release of energy from foodstuffs
water
provides the basis for body fluids of all types
appropriate body temperature
when too high or too low, physiological activities cease, primarily because molecules are destroyed or become nonfunctional
ventral
body cavity in which the abdominopelvic and thoracic cavities are subdivisions
dorsal
main cavity made up of the cranial and spinal cavity
thorcal
body cavity totally surrounded by bone