Definitions Flashcards
Homeostasis
Property of a system in which variables are regulated so that internal conditions remain stable and relatively constant
Control variable
Physiological variable that is manipulated in order to maintain the regulated variable with normal values
Regulated variables
Physiological variable for which sensors are present in the homeostatic circuit and is maintained at a stable level by a negative feedback system
Sensor
A device that measures the magnitude of a physiological variable by generating an output signal that is proportional to the magnitude of a stimulus
Set point
The range of values of the regulated variable that the homeostatic variable circuit attempts to maintain
Error detector
Determines the difference between the set point value and the actual value of the regulated variable
Controller signal
Receives info from the error detector and sends output signals to increase or decrease the activity of effectors
Effector
A component of the homeostatic circuit that is activated by the controller to change the value of the regulated variable
Simple diffusion
Movement of particles from a place of high concentration to low, down conc gradient
Osmosis
Passive transport, exclusively the movement of water across cell membranes via channel proteins
Filtration
Water and solutes being driven through the cell membrane by hydrostatic pressure, passive process
Facilitated diffusion
Carrier-mediated transport of a solute through the cell membrane down it’s concentration gradient- passive
Active transport
Carrier-mediated transport of solutes through the cell membrane up its concentration gradient using energy provided by ATO
Vesicular transport
Movement of large particles, droplets of fluid or numerous molecules at once through the cell membrane in bubble-like vesicles of membrane
