Plasma is a) a liquid ground substance containing dissolved proteins. b) a dissolved ground matrix and a lining of epithelial cells. c) a liquefied ground substance that includes several dissolved cells. d) platelets, red blood cells, and white blood cells. e) platelets and a watery ground substance.
A normal resting heart rate can range anywhere from 40 to 100 beats per minute. Below is a chart relating resting heart rate and fitness level. As can be seen on this chart, your resting heart rate can vary with your fitness level and with age â the fitter you are, generally the lower the resting heart rate.
According to the American Heart Association, a normal resting heart rate is 60 to 80 beats a minute, or about one beat per second. Well-trained athletes sometimes have resting heart rates as low as 40 beats per minute, but for those who exercise only casually or not at all, a heart rate this low is not normal. It is best to take your heart rate before you get out of bed after a night of sound sleep.