SOLUTIONS TO EXERCISES, LESSON 10
The three general components of any circulatory system are the vehicle,
The primary circulatory system of the human body is the cardiovascular system.
It includes a heart, blood, and blood vessels.
One function of the cardiovascular system is transport. Some substances carried
by the cardiovascular system are dissolved or suspended in the fluid portion of the
blood. Others are bound up in special cellular elements, the RBCs.
The cardiovascular system also provides protection against foreign substances.
This function involves active attack by white blood cells as well as other processes of
Blood is the vehicle of the cardiovascular system. Thus, it is the component that
Making up about 55 percent of the total blood volume is plasma. Its major
The physical characteristics of water make it a very good vehicle. Since water is
fluid, it can flow through the conduits. Since it can dissolve many substances, it is often
called the "universal solvent." Water is essentially non-compressible. In addition, water
has important temperature characteristics. Water has an ample heat-carrying capacity.
Water can dissipate great quantities of heat through evaporation. (para 10-10a)
Many substances are dissolved or suspended in the water of the plasma. These
substances include various gases, end products of digestion, various control substance,
and waste products. Also, there are three major plasma proteins--albumin, globulins,
and fibrinogen. The tonicity of the plasma proteins and dissolved salts are called
electrolytes. In addition, fibrinogen is important to clotting. (para 10-10b)
In adults, the formed elements make up about 40% to 45% of the total blood
The primary function of RBCs is to contain the protein called hemoglobin, which
in turn carries oxygen.
The shape of the RBC increases its capacity for the flow of substances into and
out of the cell.
Within the cytoplasm of the RBC is a special protein called hemoglobin.
Because of its iron atoms, it has a great affinity for oxygen.