A FEW WORDS about CARDIOVASCULAR SYSTEM J

A. The main …… of the cardiovascular system in the body is to transport oxygen to all tissues in
the body and remove, from these same tissues, metabolic …….. products. The system itself consists
…. the blood, the medium for exchanging oxygen, nutrients and waste products throughout the body,
the blood ……., the pipes through which the blood …….. and the heart, the pump which forces blood to
flow through the blood vessels.

                    of        vessels         waste         flows          role

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

          pressure    over      diastole           relaxes        systole      considered

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.

             amount           on           by          ventricles           generally

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 ……… vessels 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, which transports
oxygen-rich blood from the …….. ventricle to the rest of the body.

        aorta        four          right           lungs          pulmonary           great
                             ventricle      away     atrium      left

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 into 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 travels 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 ……… valves and into the aorta. From here, the aorta and
its branches carry blood to all the tissues of the body.

       mitral                valves      tricuspid          aortic       pulmonary    lungs