| A | B | 
|---|
| Hippocrates | "Father of Medicine", introduced scientific approach and ethics | 
| Monks | Cared for sick in dark and middle ages, kept ancient medical writings | 
| Galen | Studied and drew early anatomy text, used animals and fallen gladiators | 
| Andreas Vesalius | Published accurate anatomy drawings | 
| Rene Laenec | Invented the stethoscope | 
| Anton van Leeuwenhoek | Invented the microscope | 
| William Harvey | Accurately described circulation of blood | 
| Edward Jenner | Discovered smallpox vaccine by using cowpox | 
| Ignaz Semmelweis | Introduced handwashing into care of childbearing women, preventing childbed fever | 
| Louis Pasteur | Proved that microorganisms cause disease | 
| Joseph Lister | Used antiseptic spray during surgery to prevent infection | 
| Wilhelm Roentgen | Discovered X-rays | 
| Alexander Fleming | Discovered penicillin in mold | 
| Jonas Salk and Albert Sabin | Developed vaccines to prevent polio | 
| Florence Nightingale | Made nursing a respectable profession, drastically decreased deaths of soldiers | 
| Clara Barton | Nurse in Civil War, founded Red Cross | 
| Sigmund Freud | His studies formed basis of psychology and psychiatry | 
| Romans | Had good sanitation and designated places for this sick, early hospitals | 
| Greeks | Observed and measured effects of disease | 
| Hebrews | Had laws concerning handling of food which prevented illness |