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Homeostasis. KEY CONCEPT Homeostasis is the regulation and maintenance of the internal environment of the body. I. Homeostasis Conditions within the body must remain within a narrow range – like your body temperature.
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KEY CONCEPTHomeostasis is the regulation and maintenance of the internal environment of the body
I. HomeostasisConditions within the body must remain within a narrow range – like your body temperature a. Homeostasis involves keeping the internal environment within set ranges
pore sweat glands hair follicle muscle goose bump b. Control systems help maintain homeostasis. • sensors gather data • control center receives data, sends messages • communication system delivers messages to target organs, tissues • targets respond to change
II. Feedback Loops a. Negative feedback loops are necessary for homeostasis • Feedback compares current conditions to set ranges. • Negative feedback stops the change
Holding breath, CO2 levels rise O2 /CO2 level returns to normal Control system forces exhale, inhale b. Negative Feedback Loop Example:
platelets blood vessel fibrin clot white blood cell red blood cell • Example: Torn blood vessel stimulates release of clotting factors c. Positive feedback increases change • growth hormones stimulate cell division