1. Homeostasis The Human Body Compared to a Fish Tank

2. Fish Tank Conditions in the tank must be kept constant, or the same, in order for the fish to stay healthy and survive

3. In order for the fish to survive the fish tanks must maintain: warm temperature: ~78 degrees Fahrenheit high nutrient level: food for the fish, plants and bacteria high oxygen (O2) level and low carbon dioxide (CO2) level: for the fish to “breath” low nitrogen-waste level: poisonous for the fish

4. How do we maintain stable conditions in a tank? • Heater : temperature • Feeding the fish daily : nutrient levels • Air pump : oxygen • Filters : removes waste • Plants : carbon dioxide • Cleaning the tank : removes waste

5. Specific systems and organs in your body have specific roles in maintaining homeostasis Job Main System Responsible Primary Organ Responsible Respiratory system lungs Digestive system small intestine Excretory system kidneys Integumentary and nervous system skin and brain • O2 levels up and CO2 levels down • Nutrient levels up so you have energy • Waste levels down • Temperature constant

6. Integumentary (Skin) Respiratory (Lungs) Excretory (Kidneys) Nervous Integumentary Muscles Digestive system

7. Stimulus and Response Why animals and plants do what they do OR A fancy way of saying cause and effect in science.

8. What is a stimulus? Stimulus: any change in an organism’s environment that causes the organism to react. It is a fancy way of saying “cause”. Stimulus – singular Stimuli – plural Example: You are hot and begin to sweat.

9. What is a response? Response: how the organism reacts to a stimulus and results in a change in behavior. It is a fancy way of saying “effect”. Example: Getting a drink when you are thirsty.

10. There are two types of stimuli: External Stimuli and Internal Stimuli

11. What is an external stimulus? External stimulus: a stimulus that comes from outside an organism. Examples: 1. You feel cold so you put on a jacket. 2. A snake lunges at a rabbit so the rabbit runs away. 3. A dog feels hot so it goes to lay in the shade.

12. What is an internal stimulus? Internal stimulus: a stimulus that comes from inside an organism. Examples: 1. You feel hungry so you eat some food. 2. A cat feels thirsty so it drinks water. 3. You feel sick and vomit.

13. Which organ system is responsible? • One of the jobs of your nervous system is to sense changes in the environment (stimuli) and respond to them.

14. Examples of homeostasis Stimulus: your stomach is empty and your body needs fuel Response: your stomach growls

15. Examples of homeostasis Stimulus: bright light Response: your pupils get smaller

16. Examples of homeostasis Can you think of anymore? Brainstorm with your table and fill in the chart with examples 5-7

17. Exit Ticket Explain homeostasis in exactly ten words NO MORE NO LESS 10 words! Really, exactly ten words