Valves and Pumps - A Demonstration

Weblinks

Key Questions

• What is a pump?
• What is a valve?
• What is the difference between an open and closed system?

Materials

For each student

• turkey baster
• sample pumps (balloon pump, bicycle pump)
• sample valves (plumbing faucets, liquid soap dispensers)

Procedure

Part One: Discussion

1. Demonstrate the pumps. Ask questions about what is the device doing, where the water comes from, and where it goes. Ask students for examples of other types of pumps.

A turkey baster represents an open system; the water does not circulate back to the reservoir in the baster. Like wise, the balloon pump and the bike pump force air into a chamber. After explaining open and cloak systems, ask for examples of open and closed systems. An example of an open system is household plumbing. Examples of closed systems include the refrigeration units of refrigerators and hot water heating systems in houses. The human circulatory system is a closed system.

2. Demonstrate a faucet which is an example of a valve. Ask questions to stimulate a discussion such as, "What does this faucet do?" Explain that the faucet is a valve. Valves regulate the flow of a liquid or gas. Demonstrate other valves.

Notes to the Teacher: Valves and Pumps

A pump is a device for moving a liquid or gas from one place to another. Examples of pumps include bike pumps, balloon pumps, squirt guns, turkey basters, eye droppers, squirt bottles (cleaning products, Windex), and gas pumps.

A valve, at its most basic, is a device for regulating the flow of a liquid or gas (or a loose material, such as grain) by covering and uncovering openings. Examples of valves include faucets, garden hose nozzles, and soap dispensers.

Web Links

Exercise and Heart Disease

http://www.jhbmc.jhu.edu/CARDIOLOGY/rehab/exercise.chd.html
Look here for information such as the benefits of regular exercise, guidelines for safe exercise, and how to calculate your target heart rate.

McGill Virtual Stethoscope Project
Go to this link to listen to the body with a virtual stethoscope.

| lesson 1: Pulse of Life| lesson 2: Keeps on Pumpin' | lesson 3: Under Pressure | lesson 4: Sounds of the Heart | lesson 4a: Valves and Pumps | lesson 5: Lub Dub (valves) | lesson 5a: The Heart as a Pump | lesson 6: Go With the Flow | lesson 7: Lung Model | lesson 8: Ins and Outs of Respiration | lesson 9: Catch Your Breath | lesson 10: O₂ CO₂ Skit | lesson 11: X-Rays |

Habits of the Heart ©2000 Science Museum of Minnesota