Ask unlimited questions for free
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
The familiar sounds of your heart are made by the heart's valves as they open and close.
People with high total cholesterol have about two times the risk for heart disease as people with ideal levels.
Multiple sclerosis is a condition wherein the body's nervous system is weakened by an autoimmune reaction that attacks the myelin sheaths of neurons.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
For a complete list of videos, visit our video library