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THE
CARDIOVASCULAR SYSTEM
The Functions of the
Cardiovascular System
The functions of the cardiovascular
system is two fold:
 To supply all body tissues with oxygen
and nutrients and
 To transport cellular waste products to
the appropriate organs for removal
from the body
The Anatomy of the Heart
If you cut open a heart,
you can see many of
its main structural
features.
The organ is hollow, not
solid and if divided
into right and left
sides, you see the
heart contains four
cavities
Heart Chambers
 Atria--the
upper
chambers of the
heart.
 Ventricles--the
lower chambers
of the heart
Heart
Aorta
Left atrium
Right atrium
Left ventricle
Right ventricle
THE ATRIA
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The atria are
divided into 2 sides
called atrium
The right and left
atrium are the
receiving chambers
of the heart because
blood enters the
heart through veins
THE VENTRICLES
The ventricles are:
Divided into 2 separate chambers
The discharging chambers because
blood is pumped from the heart into
the arteries
 The left ventricle is the most powerful
part of the heart
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Heart Chambers
The area that is the
separating wall or partition
between the left and right
sides of the heart is known
as the septum.
The atria are divided by the
interatrial septum
The ventricles are divided by
the interventricular
septum
Superior
vena cava
Aortic artery
Pulmonary artery
Pulmonary veins
Pulmonary veins
Left atrium
Pulmonary valve
Mitral valve
Right atrium
Left ventricle
Tricuspid valve
Chordae tendinae
Interventricular
septum
Right ventricle
Inferior
vena cava
Papillary muscles
Descending aorta
HEART
HEART
THE WALL OF EACH
CHAMBER IS
COMPOSED OF A
CARDIAC MUSCLE
TISSUE REFERRED
TO AS THE
MYOCARDIUM
The Walls of the Heart
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Each chamber of the heart is lined with a thin
layer of very smooth tissue called the
endocardium
The heart has a lining called the pericardium
which consists of two layers of fibrous tissue
with a small space in between. The
pericardium consists of two layers of fibrous
tissue with a small space in between
Visceral pericardium is the inner layer of the
pericardium
Parietal pericardium is the outer layer of the
pericardium
Blood Supply to the
Myocardium
The myocardium we know is a
muscle which beats
constantly. It must have a
continuous supply of oxygen
and nutrients and it must be
able to remove waste.
This is accomplished through
coronary arteries and veins
The Heart Valves
There are two valves that separate the
atrial chambers from the ventricles
 The bicuspid or mitral valve is located
between the left atrium and the left
ventricle
 The tricuspid valve located between the
right atrium and the right ventricle and
controls the opening between the
atrium and ventricle to prevent the
backflow of blood
Heart Valves
The pulmonary semilunar valve is
located between the right ventricle and
the pulmonary artery and allows blood
going to the lungs to flow out of the
right ventricle
 The aortic semilunar valve is located at
the beginning of the aorta and allows
blood to flow out of the left ventricle
up into the aorta
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Cardiac Valve Disorders
Disorders of the cardiac valves
can have several effects on
the heart.
 Incompetent valves means
valves leak allowing some
blood to flow back into the
chamber from which it came
 Stenosed valves are valves
that are narrower than
normal, slowing blood flow
from the heart chamber
Heart Action
The heart serves as a muscular pumping
device for distributing blood to all parts of
the body.
 Contraction of the heart is called systole.
 Relaxation of the heart is called diastole.
 Thus the doctor or nurse, when taking your
blood pressure is reading your systolic and
diastolic pressure
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Blood Flow
The heart acts as two
separate pumps. The right
atrium and the right
ventricle perform a task
quite different from the
left atrium and the left
ventricle.
Let’s examine exactly how
blood flows through the
heart
Blood Flow
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The right atrium receives the
blood from tissues
From the right atrium blood
goes through the tricuspid
valve into the right ventricle
The right ventricle receives the
blood and pumps blood
through the pulmonary
semilunar valve into the
pulmonary artery and then to
the lungs where oxygen is
added and carbon dioxide is
lost
Blood Flow
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Blood rich in oxygen returns
to the left atrium which
receives blood from the lungs
Blood flows through the
mitral valve into the left
ventricle
The left ventricle receives
blood where it travels
through the aortic semilunar
valve into the aorta where
blood is pumped to all parts
of the body
Blood Flow
Blood flows into the heart muscle by way
of two small vessels--the right and left
coronary arteries
The coronary arteries are the aorta’s first
branches
If a blood clot occurs in these arteries, it’s
called a coronary thrombosis and
coronary embolism
Coronary Thrombosis
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What happens if a blockage occurs?
A coronary thrombosis blocks some part of the
coronary artery and thus blood cannot pass
through the vessel and reach the heart muscle
cells it normally supplies.
The heart muscle thus is deprived of oxygen
and the heart muscle cells soon die or are
damaged. What happens?
An individual could possible experience a
myocardial infarction and tissue death occurs
CORRECTIVE PROCEDURES
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Percutaneous transluminal coronary
angioplasty or balloon angioplasty can
perhaps be performed. A balloon is used to
open a partially blocked coronary artery
Coronary artery bypass surgery is another
surgical procedure that may be performed for
those who suffer from severely restricted
coronary artery blood flow. In this procedure
the veins are “harvested” or removed from
other areas of the body and used to bypass
partial blockages in coronary arteries
CORRECTIVE PROCEDURES
OPCAB—Drop the heart-lung machine
 Percutaneous myocardial
revascularization (PMR)
 Growth factor capsules
 Transmyocardial revascularization
 Zap plaque
 MRI
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HeartBeat
The rate and regularity of the heartbeat is
determined by electrical impulses from
nerves that stimulate the muscular
tissue of the heart
To effectively pump blood throughout
the body, the beating of the heart must
be in sync
How does this happen?
The HeartBeat
The sinoatrial node is called the
pacemaker of the heart. Electrical impulses
from the sinoatrial node start each wave of
muscle contraction in the heart which
forces blood into the ventricles.
 Impulses also travel to the atrioventricular
node which sends electric impulses to the
 Bundle of His which carries impulses to
the right and left ventricles causing them
to contract and forcing blood into the aorta
and pulmonary arteries
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Electrical Waves
The electrical events
that cause the heart
to beat can be
monitored on an
electrocardiogram
where dr’s read P
waves, QRS
complex waves, and
T waves
Heart Sounds
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The heart makes what is referred to as the
lubb/dupp sound which is caused by valves
slamming shut between the atria and ventricles
and the semilunar valves closing in the aorta and
pulmonary arteries.
The first lubb sound is caused by the abrupt
closure of the AV valves as the ventricles contract
The dupp or second heart sound is caused by
closing of both the semilunar valves when the
ventricles undergo relaxation
Blood Vessels
There are 3 major
types of blood
vessels
 Arteries
 Veins
 Capillaries
Let’s examine each
of them
ARTERIES
Arteries are large blood vessels that
carry blood away from the heart to
all regions of the body. What are
the different arteries?
 Aorta which is the largest artery
 Coronary Arteries which are
branches from the aorta and
supplies blood to the heart muscle
 Arteriols which are smaller arteries
that carry blood to capillaries
VEINS AND CAPILLARIES
Veins for a low-pressure collecting
system to return waste filled blood to
the heart. They also serve as blood
reservoirs because they can expand to
hold a large volumn of blood or
constrict to hold smaller amounts.
 Vena Cava
 Superior Vena Cava
 Inferior Vena
Blood Composition
Most blood is composed
of 55% liquid plasma
and 45% formed
elements or blood
corpuscles which
include red blood
cells, white blood cells
and platelets
Let’s examine the makeup of blood
Plasma
Plasma transports nutrients, hormones,
and waste and is composed of 91%
water and 9% clotting proteins.
If the 9% clotting proteins have been
removed from plasma, it is known as
Serum
The clotting proteins found in plasma
are Fibrinogen and Prothrombin
Formed Elements
Formed elements are suspended in the
plasma and there are many different
typed of cells. The three main types
and several subtypes of formed
elements are:
 Erythrocytes
 Leukocytes
 Thrombocytes
Erythrocytes
Erythrocytes, which are produced in bone
marrow, are red blood cells that contain
hemoglobin. Hemoglobin is the blood protein
that plays an important role in transporting
oxygen through the body. Hemoglobin is the
red pigment that give blood its color.
Normal hemoglobin ranges from 12 to 14 grams
per 100 in females
Normal hemoglobin ranges from 14 to 16 grams
per 100 in males
If your blood count is less than 10, then you are
said to be anemic
Leukocytes
Leukocytes are white blood cells that
fight diseases in the body. There are
two subgroups
 Granular leukocytes which have
granules in their cytoplasm
 Nongranular leukocytes which do not
have granules in their cytoplasm
 Let’s examine each of these subgroups
Granular Leukocytes
There are three types of granular
leukocytes that are formed in
bone marrow
 Neutrophils
 Basophils
 Eosinophils
Nongranular Leukocytes
There are two types of nongranular
leukocytes formed in lymph glands,
bone marrow, and the spleen
 Lymphoctyes which are produced to
protect the body
 Monocytes which dispose of dead
and dying cells and other debris
Thrombocytes
Thrombocytes or
platelets are also
manufactured in
bone marrow and
play an important
role in the
clotting of blood
BLOOD TYPES
Blood types are identified by certain antigens
or substances that can stimulate the body to
make antibodies. Everyones blood is one of
the following types A, B, AB, and O
 Type
A
 Type B
 Type AB
 Type O
RH System
Rh positive blood contains and antigen
called an Rh factor
 Rh negative blood does not contain the
Rh factor
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