THE CARDIOVASCULAR SYSTEM


                             vessels   waste     flows      role  uses


A. The main …….. of the cardiovascular system in the body is to transport oxygen to all the tissues
in the body and remove, from the same tissues, metabolic …….. products. The system …….. blood as
the medium for exchanging oxygen, nutrients and waste products throughout the body. The blood ……..,
i.e. the pipes through which blood …….. and the heart, the pump that makes blood circulate form the
system.


   pressure               over        diastole       relaxation        systole        considered

B. What causes blood to run through the vessels is blood …….. Just as water flows through pipes
from areas of greater pressure to lesser, so, too, blood flows through the body from areas of
higher pressure to areas of lower pressure. Blood pressure is manifested in both the heart’s
contraction, which is called …….., and in its …….., which is called …….. . A systolic blood
pressure of 120 millimetres of mercury is …….. right in the middle of the range of normal blood
pressure, as is the diastolic pressure of eighty. In common terms, this normal measurement would be
given as "120 …….. 80".


        amount                  on           by            ventricles             generally

C. Blood pressure depends …….. many factors, including the …….. of blood pumped by the heart. The
diameter of the arteries through which blood is pumped is also an important factor. …….., blood
pressure is higher when more blood is pumped …….. the heart, and the diameter of an artery is
narrow. Systolic pressure is measured when the heart …….. contract. Diastolic pressure is measured
when the heart ventricles relax.


   aorta      four        right      lungs     pulmonary            great      ventricle    away
                                            atrium left

D. The heart is a ……..-chambered organ with four main vessels, which either bring blood to or carry
blood …….. from the heart. The four chambers of the heart are: the right …….., the right …….., the
left atrium, and the left ventricle. The …….. veins include the superior and inferior vena cava,
which bring blood from the body to the right atrium. The …….. artery which transports blood from
the …….. ventricle to the …….., and the …….., the body's largest artery that transports oxygen-rich
blood from the …….. ventricle to the rest of the body.


            mitral       valves      tricuspid          aortic       pulmonary    lungs

E. If you look carefully, you can see a series of one-way …….. that keep the blood flowing in one
direction. The blood first enters the heart at the right atrium. A contraction of the right atrium
then forces blood through the …….. valve and into the right ventricle. When the right ventricle
contracts, the muscular force pushes blood through the …….. valve into the pulmonary artery. The
blood then travels to the …….. where it receives oxygen. Next, it travels out of the lungs via the
pulmonary veins, and to the left atrium. From the left atrium, the blood is forced through the ……..
valve into the critically important left ventricle. The left ventricle is the major muscular pump
that sends the blood out to the body systems. When the left ventricle contracts, it forces the
blood through the …….. valve into the aorta. From (t)here, the aorta and its branches carry blood
to all the tissues of the body.