The gastrovascular cavity provides the nutrient exchange surface in mammals.
	Interstitial fluid is the go-between for body cells and the circulatory system.
	An animal is a closed system that is separate and distinct from its environment.
	Animals are able to live as long as they remain isolated from their environments.
	Diffusion is sufficient to remove carbon dioxide, a metabolic by-product, from an ape's body.

	bone, muscle, blood, and adipose
	nervous, epithelial, connective, and muscle
	muscle, epithelial, bone, and cartilage
	blood, nervous, connective, and muscle
	simple squamous, simple cuboidal, simple columnar, and stratified squamous

	the total amount of energy an animal uses in a unit of time
	the amount of heat lost by an animal in a unit of time
	typically higher in an ectothermic animal than in an endothermic one
	determined when the organism is at rest with an empty stomach
	directly proportional to body size

	hummingbird, dog, mouse
	fish, dog, mouse
	dog, cat, mouse, salamander
	frog, rabbit, snake
	gazelle, lion, elephant

	exchange of materials with the surrounding environment
	idea that all vertebrates are built in a similar way
	correlation of structure and function
	maintenance of a relatively constant internal environment
	cooperation of body parts to form tissues, organs, and systems

	ensures that conditions in an organism do not vary too much above or below their set points
	promotes decreases in metabolic rate rather than increases
	increases the speed and rapidity of negative responses
	produces a response by lowering some set point of an organism's metabolism
	causes an effector to signal the control center of an organism, which creates the stimulus to make a response

	a stimulus will initiate a response that returns the system to near its initial parameters
	a stimulus will prevent a small change from becoming too large
	only an effector and control center are necessary to complete the control system
	a change in a variable will amplify rather than reverse the change
	the range of acceptable values for a given parameter will be narrower than if the system were regulated by negative feedback

	You roll down the car window to allow the cool breeze to blow through.
	The water in the lake is so cold that your legs become numb.
	You sweat profusely as you mow the lawn on a hot summer day.
	After sunset, you can feel heat from the warm pavement.
	As you lie on the sand, you can feel the sun's warm rays on your skin.

	produce more heat when needed
	reduce the loss of heat to the environment
	slow metabolism when food is not available
	increase heat loss by evaporation
	absorb heat from the environment

	torpor, which is a slowing of motion as exhibited by the tree sloth in the Amazon basin as it forages through the trees
	hibernation, which allows desert animals to survive summer droughts
	estivation, which is what nocturnal animals do when their temperature drops and metabolism slows during the day
	slowing respiration and circulation as well as decreasing body temperature and metabolism
	migration to avoid environmental stress and famine