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Unformatted text preview: y of the internal environment. All
thing in the body fluctuate to certain range. Negative feedback is way to maintain homeostasis.
-this diagram is about how body respond to dehydration through negative feedback, as shown in maintain
blood volume/blood pressure, and osmolarity in face of dehydration.
- See Fig. 20-13 Physiological Control Systems: General Features
1. Homeostatic mechanisms are tonically active
phasically v tonically. set point is the target of regulation 1. tonically (whole system is constant), constantly active,
keep things in range. if things happen, system shift to go
back to normal
2. "set point"=ideal range in which parameter should be
control within. that setpoint itself is subject to regulation.
when need arise, those change do not occur by fiddling
with individual pathway. change occur by changing the set
point, so system can come back to homeostasis to the new
set point. ex: temperature: chemical raise body temperature
to new set point.
3. there's not one mechanism to control something. even
like blood level have multiple mechanisms. the system is
4. do not think the mechanisms as passive, waiting for
things to occur. there ar...
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- Spring '09