define Flashcards
effector
muscles and or glands that receive signals from the nervous system and form a response to the stimulus
receptor
receive a stimulus from the source and transmit signals about what they receive to the nervous system
control centre
receives signals from a receptor in the body, sends signals to an effector to elicit a response in the body. in humans, the control centre is brain
negative feedback
any change or deviation from the normal range of function in opposed or resisted eg, body temperature, blood pressure, ph, blood glucose levels
homeostasis
maintenance of relatively stable internal conditions even through external conditions constantly change
osmoregulation
the maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentrations
thermoregulations
the maintenance of a constant internal temperature of an organism independent of the temperature of the environment
dilute
to make or become less concentrated
diffusion
passive movement of molecules from a region of high concentration to a region of low concentration
isotonic
two solutions having the same osmotic pressure, cell size doesn’t change
hypotonic
a solution that has a lower osmotic pressure relative to another solution, fluids rush IN cell gets bigger
hypertonic
a solution that has a high osmotic pressure relative to another solution, fluids rush OUT, cell gets smaller
passive transport
movement with no energetic cost, movement occurs down gradients (high to low)
active transport
movement with an energetic cost. movement occurs against gradients (low to high)
semi permeable membrane
a membrane that allows some things through but keeps out others. the cell membrane is an example of semi preamble membrane
