Biology Pages
Kimball's Biology Pages: Animal Circulatory Systems
This page has information on different types of animal circulatory systems. Scroll to the bottom of the page to find out about mammals.
Biology Pages
Kimball's Biology Pages: Anatomy of the Human Circulatory System
This site is produced by John W. Kimball, a retired biology teacher who wrote the textbook that these pages came from. The excerpt explains the different parts of the circulation system and how they function. Includes great pictures!
Earth Life
Earth Life: Blood
A very good description of the blood and circulatory systems of mammals and the important role that blood plays in the physiology of animals.