- 
  
  Distinguished veins from arteries
 - 
  
  He was the earliest physician known to use acupuncture and pulse diagnosis
 - 
  
  
 - 
  
  The first pharmacy was established in Baghdad
 - 
  
  Persian physician Rhazes was the first to identify smallpox and to suggest blood as the cause of infectious disease
 - 
  
  Frederick II created a set of laws concerning medical education standards and licensure
 - 
  
  invented the spectacles
 - 
  
  
 - 
  
  He conducted the first public dissection for his students and spectators
 - 
  
  Researchers found a way to treat the black death by applying a warm water poultice of butter, onion and garlic, plus various other remedies.
 - 
  
  He discovered capillaries, improving the knowledge of how the heart works
 - 
  
  Allowed for the study of microscopic organism
 - 
  
  He discovered blood cells and observed animal and plant tissues and microorganisms using a microscope
 - 
  
  
 - 
  
  Rene Laennec invented the stethoscope, making examinations of the heart easier
 - 
  
  Performed the first successful transfusion of human blood
 - 
  
  He used chloroform as an anesthetic, which helped during surgeries and minor procedures as it numbed the patient
 - 
  
  This helped ophthalmologist's in examining the retina and other parts of the eye
 - 
  
  Along with Charles Pravaz, Wood invented hypodermic syringes making injecting and extracting blood and other substances easier
 - 
  
  
 - 
  
  This drug is used to cure syphilis
 - 
  
  He discovered vitamin D and proved that its absence causes rickets
 - 
  
  Performed the first heart transplant
 - 
  
  He invented the artificial kidney dialysis machine
 - 
  
  Brigham and Women’s surgeons performed the nation's first triple-organ transplant, removing three organs from a single donor and transplanting them into three individual patients
 - 
  
  Ralph Weissleder developed fluorescent molecular probes that fluoresce upon contact with tumor enzymes, allowing the detection of tumor cells
 - 
  
  
 - 
  
  Found that C-reactive protein predicts the chances of developing heart disease, leading to new guidelines for predicting cardiovascular disease
 - 
  
  While studying a tiny cluster of nerve cells behind the eye, researchers discovered a pathway involved in how the brain’s circadian clock sends signals that control the body’s daily rhythms
 - 
  
  Researchers discovered the architecture of the first transmembrane protein-conducting channel, paving the way for an understanding of how proteins are transferred
 - 
  
  Conducted a study to combat the herpes virus type 2, creating a vaccine
 - 
  
  Scientists discovered how to use human skin cells to create embryonic stem cells