Homeostasis and Behavior

1. Homeostasis and Behavior

2. Every organism constantly interacts with its environment. http://www.youtube.com/watch?v=h6-evXswaQs

3. stimulus vocabulary word! • stimulus - anything that causes a reaction or change in an organism. Example:An animal is cold so it moves into the sun. Example: Getting a drink when you are thirsty.

4. response vocabulary word! • response - an organisms reaction to a stimulus. Example: An animal is cold so it moves into the sun. Example:Getting a drink when you are thirsty.

5. Environments change all of the time. • External conditions like weather change • Internal conditions like hydration and hunger change

6. vocabulary word! • homeostasis – maintaining a stable balance in the body. • Organisms’ bodies constantly respond to stimuli to maintain homeostasis.

7. How are stimuli detected? • All organisms are able to detect changes in and around them and to respond to them.

8. external stimulus vocabulary word! • external stimulus – stimulus coming from outside an organism. • light, touch, water, gravity, electricity, temperature, darkness etc…

9. Examples: 1. You feel cold so you put on a jacket. 2. A snake lunges at a rabbit so it runs away. 3. It is a very hot, sunny day so a dog sits in the shade.

10. internal stimulus vocabulary word! • internal stimulus – a stimulus coming from inside an organism. • chemicals and hormones

11. Examples: 1. You feel hungry so you eat some food. 2. A cat feels thirsty so it drinks water. 3. A dog feels sick so it’s body triggers a fever.

12. Where do responses come from? • When a stimulus is detected, the nervous system gathers the information. • Then it decides how to respond • quick – nerve impulses • slow - hormones

13. responses vocabulary word! • taxis – an animal’s movement toward or away from a stimulus. • tropism – a plant’s movement toward or away from a stimulus.

14. To maintain homeostasis, organisms must constantly respond to external and internal stimuli. • behavior - set of actions taken by an organism in response to a stimulus. • fight or flight • finding food • hibernation • migration • food storage • dormancy vocabulary word!

15. fight or flight • Many animals must decide to fight or flee when in danger. • The body produces adrenaline to prepare them. • The heart and breathing rates increase.

16. finding food and shelter • living organisms must have a food source and a place to live. • hunger is an internal stimulus • most organisms live where they can find food

17. migration vocabulary word! • migration – mass movement of a species toward resources like food, water or warmer temperatures.

18. hibernation vocabulary word! • hibernation – deep sleep during which an animal slows all of its body processes to save energy. • estivation – deep sleep during hot temperatures which an animal slows all of its body processes to save energy.

19. plant strategies • Plant are not able to migrate so they use different techniques to survive. • food storage – plants can store food in bulbs or tubers (onions and potatoes). • dormancy – plant temporarily stops growing. Some also shed leaves.

20. Homeostasis • An organisms response to internal and external stimuli helps to maintain homeostasis • Homeostasis – balance or equilibrium inside a living organism • Blood sugar levels • Sweating/shivering • Fever • Vomiting • Plant tropisms

21. Blood Glucose Levels • In order to maintain homeostasis, your body tries to keep a certain blood glucose level • When blood glucose is low, you should eat • When blood glucose is high, your pancreas should release insulin • Problems with this system can create diabetes

22. Pill Bugs http://youtu.be/p97-JHO-RNM