Learn about the drugs put into contact lenses on this Moment of Science.
Pacemakers are electrical devices that monitor the heart rate and helps get it up to speed when it starts pumping too slowly. The small battery powered disk is inserted just beneath the skin above the heart. A couple of attached wires monitor the heart and carry signals and impulses to and from the heart.
More importantly, rats and humans often suffer from the same diseases. That’s because humans and rats have the same basic physiology, similar organs, and similar body plans.
Modern medicine, along with better living conditions and healthier diets, enables many people to live into their seventies and eighties. Deaths due to infectious diseases like smallpox and polio have declined, and formerly fatal conditions like diabetes and heart disease can be kept in check.