Homeostasis The Human Body Compared to a Fish Tank

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

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 (O 2 ) level and low carbon dioxide (CO 2 ) level: for the fish to “breath” low nitrogen-waste level: poisonous for the fish

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

Specific systems and organs in your body have specific roles in maintaining homeostasis Job O 2 levels up and CO 2 levels down Nutrient levels up so you have energy Waste levels down Temperature constant Main System Responsible Primary Organ Responsible Respiratory system lungs Digestive system small intestine Excretory system kidneys Integumentary and nervous system skin and brain

FishbowlHuman Body Function Glass tank Barrier- keep certain things inside and certain things outside Air pumpKeep O 2 level stable: high FilterKeeps waste level stable: low HeaterKeep temperature stable FeederKeep nutrient level stable: high Integumentary (Skin) Respiratory (Lungs) Excretory (Kidneys) Nervous Integumentary Muscles Digestive system

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

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

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.

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

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.

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.

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.

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

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

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

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