Organ Systems and Homeostasis

cell

basic unit of all forms of life

homeostasis

relatively constant internal physical and chemical conditions that organisms maintain despite changes in internal and external environments

tissue

group of similar cells that perform a particular function

organ

group of tissues that work together to perform closely related functions

organ system

group of organs that work together to perform a specific function

receptor

senses a change in the environment (stimuli)

control center

analyzes information and determines appropriate response

effector

a muscle or gland that responds according to the control center

positive feedback

feedback that tends to amplify the initial stimulus; takes body away from starting point

negative feedback

feedback that counteracts the initial stimulus; returns body to starting point