1. Homeostasis Introduction

2. Homeostasis – the process of maintaining a constant internal environment despite changing external conditions

3. Homeostasis
Ensures that the organs of the body operate within their normal limits and are working efficiently
Based on a feedback system
Information is sent to a control center which directs the organ to react accordingly

5. Two Major Control Centers
Brain – nervous system
Glands – endocrine system

6. Several Factors (Activities) must be regulated to maintain homeostasis:
1. Temperature
Skin
Controlled by the hypothalamus

7. Several Factors (Activities) must be regulated to maintain homeostasis:
2. Heart Rate
Heart
Controlled by the medulla oblongata

8. Several Factors (Activities) must be regulated to maintain homeostasis:
3. Respiration Rate
Ribs and Diaphragm
Controlled by the medulla oblongata

9. Several Factors (Activities) must be regulated to maintain homeostasis:
4) Blood Pressure
Heart and Arteries
Controlled by the medulla (cardiac output, arteriole resistance)
Kidneys
Controlled by the hypothalamus which directs the pituitary gland to control water levels in the blood

10. Several Factors (Activities) must be regulated to maintain homeostasis:
5) Water Balance
Kidneys
Controlled by the hypothalamus which directs the pituitary gland

11. Several Factors (Activities) must be regulated to maintain homeostasis:
6) Blood sugar levels
Pancreas
Controlled by the Islet of
Langerhands controls sugar levels
Insulin – reduces blood sugar levels
Glucagon – increase blood sugar levels

12. Several Factors (Activities) must be regulated to maintain homeostasis:
7) Detoxification
Liver
Controlled by the liver which removes harmful substances from the blood and inactivates them, returning them to the blood to be removed by the kidneys

13. Remember… in order to maintain homeostasis (process of maintaining a constant internal environment despite changing external conditions) these activities must be regulated by your control centers!!

14. Now to build up to these high function levels of organization in an organism that help maintain homeostasis let’s begin with the basic building blocks…