Blood: A Working System
Investigate blood at different scales, separate its mixture, trace what it transports, and model how its components respond when a blood vessel is injured.
Prepare a Virtual Blood Smear
Guide a trained laboratory professional through collecting a labeled sample and preparing a thin smear. Then unlock the microscope.
After placing the drop, drag the angled spreader toward the right to make a thin feathered smear.
Safety boundary: This is a virtual demonstration. Students should only view commercially prepared blood slides and should never collect or prepare blood in class.
Virtual Blood Microscope
Begin with low magnification. Focus the image, then zoom in to look for patterns. The field is an instructional model, not a diagnostic blood smear.
Where does this blood travel?
Start with the whole body. Then zoom into the heart, a network of blood vessels, and the blood inside them.
Your place in the body
More oxygenLess oxygen
Blue is a diagram color. Blood is always red.
One system. Two connected loops.
Follow blood from the body to the lungs and back again. The heart keeps both loops moving.
The heart is a muscular pump.
Watch the muscle squeeze, the chambers fill, and the valves open and close. Choose a structure to see its job.
Different vessels do different jobs.
An artery carries blood away from the heart. Smaller branches lead to capillaries, then veins return blood.
A moving mixture inside the vessels.
This is the same material you examined under the microscope. Its components work together throughout the body.
Illustration credits
Body atlas adapted from Mariana Ruiz Villarreal (LadyofHats), with updates by Jmarchn · public domain. Heart illustration adapted from Wapcaplet, Yaddah, Stenemo and Jmarchn · CC BY-SA 4.0. The adapted heart artwork is shared under that license. Color, labels, animation and interactive layers added for this lab.
Blood Is a Mixture
The sample has already been separated. Zoom into each layer to investigate what collected there, then shake the tube to remix the components.
≈55%
≈45%
Less dense liquid portion
White blood cells and platelets
Denser cells settle below
Plasma layer
A yellowish liquid, mostly water, with dissolved nutrients, salts, proteins, and wastes. Individual dissolved materials are represented symbolically.
Scale note: The white-blood-cell and platelet layer is enlarged in the tube so it can be selected. In a real separated sample, it is typically less than 1% of the blood volume.
Why Are Blood Vessels Everywhere?
Select a tissue. The tissue surrounding the vessel will change, but the same four blood components continue traveling through its vessels.
Blood's Response to Injury
Watch blood continue through a damaged vessel. Compare an open skin tear with an internal muscle injury, then follow the early response.
