Balancing Act-Mechanism of Homeostasis

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Homeostasis

Mechanisms of Homeostasis

What is Homeostasis ?Homeostasis is the regulation and maintenance of the internal environment of the body

Mechanisms of Homeostasis

I. Why Homeostasis?Conditions within the body must remain within a narrow range – like your body temperature

a. Homeostasis involves keeping the internal environment within set ranges

Mechanisms of Homeostasis

How does Homeostasis work?

b. Organ systems work together to maintain homeostasis so organism can survive and function normally

Mechanisms of Homeostasis

c. Control systems help maintain homeostasis. Receptor : Organs that gather data

control center : receives data/ messages

communicate messages to effector organs

Effector : Organs that respond to change

pore

sweat glands

hairfolliclemuscle

goosebump

Mechanisms of Homeostasis

Example:

O2 / CO2 level returns to normalEffector

ResponsesControl system forces exhale, inhale

Control system gets information

Holding breath, CO2 levels rise

ReceptorSenses change

NervousRespiratoryMuscular

Mechanisms of Homeostasis

II. Feedback Loops

Feedback compares current conditions to set ranges.

Two types:a. Negative feedback loopsb. Positive feedback loops

Mechanisms of Homeostasis

Negative Feedback

Negative feedback stops the changeExample: Maintaining body temp.

Mechanisms of Homeostasis

c. Positive feedback increases change –Example: Torn blood vessel

stimulates release of clotting factors

–growth hormones stimulate cell division

platelets

fibrin

white blood cellred blood cell

blood vessel

clot