Browse by Grade & Topic: Human Systems and Health

Trace the path of blood through a beating heart and the network of blood vessels that supplies blood to the body. Take blood samples from different blood vessels to observe blood cells and...

Digestion is a complex process, involving a wide variety of organs and chemicals that work together to break down food, absorb nutrients, and eliminate wastes. But have you ever wondered...

Everything we know about the world comes through our senses: sight, hearing, touch, taste, and smell. In the Senses Gizmo, explore how stimuli are detected by specialized cells, transmitted...

Observe how different colors of light are reflected or absorbed by colored objects. Determine that white light is a combination of different colors of light, and that one or more component...

Once light enters the eye, it must be focused on the retina. Manipulate the pupil diameter to regulate the amount of light that enters then eye, then change the lens shape to focus light....

FREE with no time limit!

Observe how photoreceptors on the retina are stimulated by different colors of light. Determine that cone cells are stimulated by specific colors of light and enable us to see color, while...

Test your hearing range by listening to low-, medium-, and high-frequency sounds. Compare the relative loudness of sounds at each frequency to create an equal-loudness curve. In a quiet...

Control a simulated person running on a treadmill. Your challenge is to use clothing, exercise, and sweat to maintain a constant body temperature as air temperature goes up and down....

FREE with no time limit!

Explore a wide variety of cells, from bacteria to human neurons, using a compound light microscope. Select a sample to study, then focus on the sample using the coarse and fine focus...