Homeostasis Flashcards
1
Q
homeostasis definition
A
maintain variability around a set point
2
Q
negative feedback
A
- turns down
- attempts to maintain set point
3
Q
positive feedback
A
- turns up
- attempts to amplify the variable
4
Q
examples of negative feedback
A
- BP at rest
- Blood glucose
5
Q
examples of positive feedback
A
- BP at exercise
- Oxytocin
6
Q
highly controlled homeostatic variables
A
- BP
- CO2
- O2
- Blood Glucose
- Core Body Temperature
- pH
- Electrolytes
7
Q
gain definition
A
effectiveness of controlling physiological variable
8
Q
high gain
A
fast, small response (core body temperature)
9
Q
low gain
A
slow, large response (BP)
10
Q
Order of feedback loop
A
- Stimulus
- Sensor/Receptor
- Afferent pathway
- Integrating Center
- Efferent Pathway
- Target/Effector
- Response
11
Q
a-pancreatic cells secrete
A
glucagon
12
Q
b-pancreatic cells secrete
A
insulin, amylin
13
Q
what does deconditioning (bed rest) do?
A
causes a low gain system in a normally high gain system, inability to maintain BP with ambulation (orthostatic intolerance)
14
Q
what does dehydration do?
A
- volume contraction
- high gain system
- large increase in ADH to reclaim H2O
15
Q
what does hydration do?
A
- volume expansion
- low gain system
- dont need to work hard to recover H2O
