1. Maintaining Life & Homeostasis Notes

2. Necessary Life Functions
MAINTAINING BOUNDARIES – inside stays distinct from outside
MOVEMENT – change in body position & transport material inside body
RESPONSIVENESS – ability to sense change in environment & react

3. DIGESTION – process of breaking down ingested food
METABOLISM – sum of all chemical reactions occurring in body
EXCRETION – process of removing waste

4. REPRODUCTION – producing offspring
GROWTH – increase in size

5. Survival Needs NUTRIENTS – contains chemicals for energy
OXYGEN – needed to release energy
WATER – required for metabolism; stable body temperature

6. STABLE BODY TEMPERATURE - needed for metabolism
ATMOSPHERIC PRESSURE – force exerted by weight of air; allows for exchange of gases

7. Homeostasis
body’s ability to maintain relative stable internal conditions
HOMEOSTATIC IMBALANCE – inability to maintain homeostasis; cause of illness, disease, or aging

8. Homeostasis Control Mechanism (Feedback Loop)
RECEPTER – sensor that detects change; relays information to control center
CONTROL CENTER – determines set point; analyze information received by receptor, then determines appropriate response

9. EFFECTOR – receive information from control center & produce a response
2 Types:
NEGATIVE FEEDBACK MECHANISM - decrease original stimulus

10. POSITIVE – increase original stimulus