One Little Red Corpuscle May Travel One
Hundred and Sixty-Eight Miles
in a Single Day.
The speed at which the blood circulates in the veins and arteries of a
healthy man is something surprising. All day long, year in and year out,
the round trips continue from the heart to the extremities and back again.
The red blood corpuscles travel like boats in a stream, going to this or
that station for such service as they have to perform; and the white
corpuscles, the phagocytes, dart hither and thither like patrol boats,
ready to arrest any contraband cargo of disease germs.
The mileage of the blood circulation reveals some astounding facts in our
personal history. Thus it has been calculated that, assuming the heart to
beat sixty-nine times a minute at ordinary heart pressure, the blood goes
at the rate of two hundred and seven yards in the minute, or seven miles
per hour, one hundred and sixty-eight miles per day and six thousand three
hundred and twenty miles per year. If a man of eighty-four years of age
could have one single blood corpuscle floating in his blood all his life
it would have traveled in that same time five million one hundred and
fifty thousand eight hundred and eight miles.