9781422282953

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S T E M I N C U R R E N T E V E N T S

INTRODUCTION Marvels of Medicine

F or thousands of years, people around the world have fought to combat the outbreak of disease and promote goodhealth.Inancient times, some cultures thought diseasewas the result of evil spirits, and they turned to religion, not science, in search of cures. People called shamans were both spiritual leaders and healers. Early doctors in such places as Egypt andChina also discovered that certain herbs could cure some diseases, and scientists still study the power of some plants and herbs to prevent or treat diseases. Later, the Islamic countries of the Middle East created the first large hospitals, which also trained doctors. Islamic books on surgery and othermedical practices were used for several hundred years across parts of Europe, North Africa, and Asia. Over the last 500 years, the rise of modern science has led to a greater understanding of what causes many illnesses and how they can be treated. Themicroscopewas an important tool for studying the human body, which

led to the understanding that it and all other living things are made up of cells. Some illnesses, such as cancer, start with changes that occur at the cellular level. The microscope also led to the discovery of microorgan- isms, such as bacteria and viruses. Scientists learned that they play a role in causing many diseases. With the “germ theory” of disease, doctors saw that good hygiene could prevent disease, and that drugs that killed a particular microorganism could cure some illnesses.Late in the19thcentury, a new piece of medical technology appeared: the X-ray.For the first time, doctors could see inside the body of a living patient to diagnose illnesses or detect broken bones. One of the greatestmedical break- throughs was the use of vaccines to prevent illness.Patients receive small doses of thevirus that causes adisease. It stimulates the body’s own defenses. If the actual virus enters the body afterward, the patients are able to fight off the disease.An early kind of