PBS
Pbs Learning Media: Amazing Heart Facts
This feature from the NOVA: "Cut to the Heart" highlights facts about the heart, including its size and placement, and will help you to understand the importance of this wondrous organ in our bodies.
University of Utah
University of Utah: Cardiovascular Pathology Index
This site features a detailed index of photographs for cardiovascular pathology. You can see what a normal human heart looks like and what a sick one looks like too. Come and check it out.
McGraw Hill
Glencoe Biology: Circulatory System: Self Check Quiz
Five multiple-choice quiz questions covering the human circulatory system. Students have the opportunity to check their answers after submitting their results.
BioEd Online
Bio Ed Online: It Begins With the Heart
In this lesson, students can learn basic information about the human heart, including its role in circulation, and its external appearance.
OpenStax
Open Stax: Anatomy & Physiology: The Lungs
Students learn the overall function of the human lungs, and then summarize the blood flow pattern associated with the lungs.
North Central Regional Educational Laboratory
Kids learn.org: Circulatory System
What do you know about the circulatory system? This site features several links to help you increase your knowledge of this fascinating human body system.
BioEd Online
Bio Ed Online: Microgravity
In this lesson students will use water balloons to simulate the effects of gravity and microgravity on fluid distribution in the body.