Homeostasis Flashcards
Homeostasis
-condition of equilibrium (balance)
Control systems:
-detect deviations from normal
-integrate info
-make adjustments
Set point
-normal range for a given system
Circadian rhythm
-24hr endogenous (internal) oscillators
-major regulatory factor
Intrinsic controls
-local to organ
Extrinsic controls
-outside organ
-nervous and endocrine
Feedback loops
-responses after a change (negative and positive)
Feedforward loops
-responses made in anticipation of change
Components of negative feedback loop
-opposes initial change
1) sensor
2) control center
3) effector
Explain the negative feedback loop that occurs when one gets cold
Explain the negative feedback loop that occurs when one is warm
Explain blood pressure control
What happens when you eat? (blood glucose increases)
What happens when blood glucose drops?
What happens when blood Ca2+ levels are high?
What happens when blood Ca2+ levels are low?
Positive feedback loops
-amplifies initial change
-snowball effect
-until an outside factor shuts it off
Components of a positive feedback loop
1) initial stimulus
2) response
3) increase in stimulus
4) outside factor shuts off
What happens when someone goes into labor?
Disorder
-abnormality of function
Disease
-illness characterized by a recognizable set of signs and symptoms
What impact does age have on homeostasis
-progressive decline in the body’s ability to restore homeostasis
Example of feedforward mechanism
-saliva production prior to eating
-preparing for the breakdown of carbohydrates
Explain the feedforward mechanism for exercise
