Homeostasis Flashcards
what is hoeostasis?
the maintenance of aconstant internal environment by the use of control systems and negative feedback
how is homeostasis maintained?
by self-regulating processes which involve control systems and negative feedback
what does it mean that the systems are dynamic?
the conditions are changing all the time
why is homeostasis important?
Organisms can operate efficiently.
Enzymes will be able to work within narrow limits.
Living organisms with control systems are independent of their environment.
Body temperature, blood pressure, heart rates, and concentration of the blood can be controlled.
Each cell can control the levels of metabolites by feedback inhibition or end-product inhibition.
what is needed for homeostasis to take place?
control system
what does a control system consist of?
a detector, regulator and effector
what is the purpose of a control system?
to respond to changes in the level of a detected variable by working to bring the level of the variable back to the desired or ideal level (set point)
why are control systems dynamic?
because the level of the variables are constantly changing
how is over-correction of a change prevented?
through the involvemet of negative feedback in the control system
what are the detectors?
receptors or specialized cells that respond to particular stimli and convert that information into nerve impulses that take the information to the regulator in the control systems
where are detectors present?
in organs, around blood vessels
what is the set point?
the ideal/ optimum level of a particular variable
what is the function of the regulator/ control center?
The regulator is receptive to messages from the detector in a control system.
When it receives those messages, it makes comparisons between the information received and the set point, for a particular variable.
Then it sends messages to the effector. These messages can be stimulatory or inhibitory so that a change will be brought about to eventually restore the variable to the set point.
what is an effector?
a muscle/ gland which is stimulated or inhibited by the regulator to contract or relax, or secree hormones or stop secretion, respectively
this brings about a response by the control system
what is negative feedback?
the switching off or corrective mechanisms once the reference point or set point is reached.
