The Importance of Organ Donation
Organs are systems of cells and tissues that perform a specific task -- respiration, for example, or ridding the body of waste. Organs are equipped with higher than necessary capacity. For instance, a 20-year-old's heart can pump 10 times more than the amount of blood needed [source: NLM]. This reserve capacity diminishes as we age, however. The heart, lungs and kidneys especially diminish over time, more so than other organs.