Ask unlimited questions for free
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
The ratio of hydrogen atoms to oxygen in water (H2O) is 2:1.
By definition, when a medication is administered intravenously, its bioavailability is 100%.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
For a complete list of videos, visit our video library