This site provides an explanation of smooth muscle, muscle that is present in the walls of hollow organs like the urinary bladder, uterus, stomach, intestines, and in the walls of passageways, such as the arteries and veins of the...

This simulation explores the relationship between the amount of surface area in the small intestine and the rate at which it absorbs food particles into the circulatory system.

Learn how our body works at this personal site from a fourth grade teacher. Colorful graphics and lots of fun facts.

A detailed description of the human heart and its parts.

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.

This comprehensive site from Kids Health provides an indepth look at the characteristics of blood, its functions, and its importance. This site is a great starting point for understanding blood. Also includes links to similar sites.

A downloadable PDF comic book in Spanish with information on how to prevent heart disease and promote healthy hearts.

A downloadable PDF comic booklet with information on how to prevent heart disease and promote healthy hearts.

[Free Registration/Login may be required to access all resource tools.] Describes how the heart pumps blood throughout the body.

This concise PBS NOVA site contains interesting facts about the heart and how it works.

An informational text about the human heart, its parts, and it functions. A question sheet is available to help students build skills in reading comprehension.

Explore the relationship between pressure and vessel diameter and create a model that represents how elevated blood pressure may affect weakened vessels. Design and critique a repair device.

Investigate biotechnology design by creating a model of a one-way valve from plastic tubing. Describe the mechanical action of the valve.

A comprehensive resource on earthworms, offering the following sections: "Facts about Earthworms," "Migration and Annual Cycle," and "Lessons Activities and Information."

Test your knowledge of the heart by finding the different parts in this 13 question quiz.

[Free Registration/Login may be required to access all resource tools.] Discusses the different types of blood vessels and their roles.

WebMD offers information on congenital heart disease, including types, symptoms, diagnosis, and treatment.

[Free Registration/Login may be required to access all resource tools.] What does the heart look like? How does it pump blood? Learn more about the heart in this learning module produced by CK-12.

This PBS site has a concise explanation of how the heart works. There is also a moving diagram of a working heart.

This resource provides an overview about heart disease.

Read this passage and study the graphic to complete the five-question quiz related to the Chronic myelogenous leukemia and Philadelphia Chromosome.

Practice for the MCAT by answering questions based on the given bar graphs showing apoptosis and cytokinesis rates.

Molarity and osmolarity are two distinct concepts. Molarity (M) is the number of moles of solute per liter of solution. The unit of molarity is the mole (mol). Osmolarity (Osm/L) is the total concentration of all solutes in the solution....

Learn how molarity and molality differ. The molality of a solution is equal to the moles of solute divided by the mass of solvent in kilograms, while the molarity of a solution is equal to the moles of solute divided by the volume of...