Page 124 - Design in Nature

CHAPTER 6

Blood:

Life-giving Fluid

Crucial Functions of Blood
Blood is a liquid that is created to give our bodies life. As long as it
circulates within the body, it warms, cools, feeds and protects by cleansing

the body of toxic substances. It is almost solely responsible for
communication within our bodies. In addition, it immediately repairs any
fractures in the walls of veins and so the system is rejuvenated.
On average, there is 1.32 gallons (5 litres) of blood in the body of a
human weighing 132 pounds (60 kilograms). The heart can make this
amount of blood circulate in the body easily within a minute. However,
while running or exercising, this rate of circulation can increase to five times
as high. Blood flows everywhere: from the roots of the hair to the toes, inside
veins of varying sizes. The veins have been created of such a flawless
structure that no clogging or sediments are formed. A variety of nutrients
and heat are carried through this complex system.

Oxygen Carrier
The air that we breathe is the most crucial substance for our survival.
The oxygen is as necessary for the cells' burning of sugars in energy
production as it is for setting a log on fire. This is why oxygen has to be
carried from the lungs to the cells. The blood circulatory system, resembling
a complicated network of pipelines, serves this very purpose.