Stimulus & Response Notes Title your page: Stimulus & Response Notes

Put these notes in Slide Show/ Full Screen Mode. There are examples at the end that give you practice identifying stimulus and response. As you click the “next arrow” the answer will come up. Full Screen mode will let you guess before seeing the answer. OR

Stimulus Achange in organism’s environment A change in organism’s environment  Internal Stimulus  External Stimulus

Internal Stimulus (change from INSIDE an organism)  Feeling “hungry” or “thirsty”  Ingesting bad food (food poisoning)  Germs  Needing to urinate  Needing to sneeze  Fatigue (tiredness) External Stimulus (change from OUTSIDE an organism)  Touching a hot stove  Hearing a loud sound  Predators: “fight or flight”  Fight- organisms’ natural reaction to fight another when scared  Flight- organisms’ natural reaction to run away from fear/ danger  Temperature (heat or cold)

Response An organisms reaction to change.  Hearing a loud sound  jumping in fright  Food poisoning  vomiting  Heat  sweating KEY Stimulus Response Stimulus and Response have a similar relationship to Cause and Effect. Important

FYI  For this topic, you are only required to know if the STIMULUS is internal or external. You will NOT be required to know if the RESPONSE is internal or external. READ ONLY

External Stimulus Response Opening a can of dog food stimulates a dog’s salivary glands. This stimulation came from outside the dogs body which makes it external. The response is drooling. Draw and write everything on this slide.

Homeostasis The tendency of a system or maintain internal stability. Synonyms: equilibrium, sameness, balance The purpose of response to stimuli in organisms is to maintain homeostasis, a balance within it’s internal systems. Same State of balance

 Stimulus brings organism OUT of homeostasis (internal balance)  Ex: Hot temperature  Response is the body’s natural reaction to bring the organism back INTO homeostasis.  Ex. Sweating

Examples  Stimulus = Is this internal or external? Is this internal or external?  Response =  Stimulus = Is this internal or external? Is this internal or external?  Response = Lack of water Wilting Bacteria or Virus Fever Use the picture to determine each answer. When you click the “next arrow” the correct answer will appear. Mentally, make a guess for each one before revealing the answer. Write both examples in your notebook. Drawing the picture is optional

ASSIGNMENT:  Write a summary explaining: Internal Stimulus Internal Stimulus External Stimulus External Stimulus Response Response Homeostasis Homeostasis Use examples to support your explanation As a resource, there is a Brain Pop video on NetSchool. You can use this Pavlov’s dog example or you can make up your own.