This site offers a brief discussion of the mode of transmission and lists those at greatest risk. This site has a lot of text explaining about strokes, aneurysms, and other phenomena related to cerebral circulation. There are many links to other medical centers that contain diagrams and images of angiograms. This site features a multitude of links providing information on polio and other diseases with similar symptoms. A good explanation of the cause of tinnitus, plus links to additional information and a bibliography.
Pictures are available on some of the sites.
A clear drawing explains the roles of receptors and carrier molecules in this process. A photomicrographic atlas of blood cells and bone marrow. This site illustrates photomicrographs of blood parasites and has links to other image-containing sites. This site discusses heart risk factors in laypersons' terms. A technical discussion about the relationship between free radicals and atherosclero sis.