Also found in: Dictionary. Related to Investment income: Net Investment Income, Interest income. The revenue from a portfolio of invested assets. The income one derives from capital gains, dividends, and other activities related to the purchase and sale of securities. This differs from wages and salary primarily in that one does not need to work for investment income. One can manage one's investments oneself, or one can hire a money manager to do it.
Heart, How It Works. The normal heart is a strong, muscular pump a little larger than a fist. It pumps blood continuously through the circulatory system. Each day the average heart beats (expands and contracts) 100,000 times and pumps about 2,000 gallons of blood. In a 70-year lifetime, an average human heart beats more than 2.5 billion times. The circulatory system is the network of elastic tubes that carries blood throughout the body.
With a resting heart rate around 75 beats per minute, that's just over 5 liters per minute. Coincidentally, the average adult male has about 5 liters of blood in his body at any given time. So, as a rule of thumb, you can expect the entire blood volume to pass through the heart once per minute. Note this is at rest.