Cardiovascular System
Prima & Passorn
Functions of the
Cardiovascular System
Delivering materials to cells;
 Carrying wastes away;
 Additionally, blood contains
cells to fight diseases
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Delivering Materials
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Starting by the heart, which pumps the
blood in your blood vessels continuously
throughout your body, carrying many
essential substances your body needs,
like glucose.
Removing Wastes
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The cardiovascular system also
transports wastes from your cells. As an
example, when cells break down glucose
for energy, carbon dioxide is released as
waste, which will be picked up by the
blood, transported to the lungs, and
exhaled.
Fighting Diseases
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Your blood contains cells that can help
preventing you from diseases, blood loss,
the entry of microorganisms, and seals
cuts.
The Heart
Atrium: upper chamber of the heart
 Ventricle: lower chamber of the heart
 The atria (atrium, plural form) receive blood
entering the heart. Blood flows from the atria
to the ventricles, which pump blood out of
the heart.
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Your Heartbeat
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First the atria contract, pumping blood into
the ventricles. Then the ventricles contract,
pumping blood into the large blood vessels
going toward the lungs or toward the rest of
the body.
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The rate at which your heart muscles contract
is regulated by the pacemaker, a small group
of cells in the wall of the right atrium. It
receives messages from your brain to increase
or decrease your heart rate.
Blood Vessels
Blood vessels are networks for transferring
blood pumped by your heart. The three main
types of blood vessels in your body are:
 Arteries
 Capillaries
 Veins
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Arteries are blood vessels that carry blood
away from the heart. They mostly carry
oxygen-rich blood except for arteries that
carry oxygen-poor blood from the heart to the
lungs.
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Capillaries are the branches for the smallest
arteries. As blood flow through the capillaries,
oxygen and dissolved nutrients diffuse
through the capillary walls and into your
body’s cells, and wastes from your body cells
diffuse into the blood.
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Veins are large, thin-walled blood vessels
formed by small blood vessels that join
together from the capillaries, and carry the
blood to the heart.
Blood pressure is the force with which your
blood pushes against the walls of your blood
vessels.
 Normal blood pressure: 90/60 to 119/79
 Low blood pressure: lower than 90/60.
Medications dehydration, and allergic
reactions.
 High blood pressure: consistently 140/90 or
greater, as known as hypertension
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Blood: The Four Components
Plasma: the liquid component of the blood
Red Blood Cells: the cells that carry oxygen from
the lungs to all the parts of your body
White Blood Cells: help protect you against
diseases and foreign substances
Platelets: cells fragments that play an important
role in the blood clotting process
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Blood Types
A person’s blood type is determined by the proteins
present on the surface of the red blood cells.
Blood type is determined by the presence or absence
of the Rh factor protein.
Transfusions
During a transfusion, blood from a donor is transferred
to the patient’s bloodstream.
If a patient is given the wrong blood type during a
transfusion, the blood will clump together in the
patient’s blood vessels. This is a life-threatening
reaction.
Cardiovascular Diseases
Hypertension and high blood cholesterol are two factors
that increase your risk of heart attack and stroke.
Hypertension
 Hypertension damages blood vessel walls due to the
increased force of the blood.
 The heart must work extra hard to pump blood through
the body.
 The heart muscle may weaken and eventually fail to
pump blood adequately.
Blood Cholesterol
Cholesterol is transported in your blood by carriers known
as lipoproteins.
Low- density lipoproteins(LDL) - carry cholesterol to body
tissues for use or storage.
 LDL is called “bad cholesterol” because it may become a
component of plaque.
 If the level of LDL cholesterol in your blood is continually
high, you could develop atherosclerosis.
 Atherosclerosis is a condition in which an artery wall
hardens and thickens due to plaque buildup.
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High-density lipoproteins(HDL) pick up excess
cholesterol from body tissues and artery walls and carry
it to the liver.
HDL is called “good cholesterol” because it cleans your
arteries of excess cholesterol.
If your HDL levels are low, you could be at increased risk
for atherosclerosis.
Heart Attack and Stroke
As artery walls thicken, blood flow is constricted.
 If the artery carries blood to your heart muscles, a
heart attack may result.
 If the artery carries blood to your brain, a stroke
may result.
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Other Cardiovascular Disorders
Heart Murmur
Murmur is a sign of a problem in the heart , such as valve
not closing properly.
Opening in Heart Wall
If the hole does not seal after birth, oxygen-rich and
oxygen-poor blood will mix in the heart, reducing its
efficiency.
Arrhythmia
 Arrhythmia- irregular heartbeat.
 Some arrhythmias are signs of serious heart conditions.
Keeping Healthy
To help maintain cardiovascular health, you should
exercise regularly: eat a nutrient-rich, balanced diet: and
avoid smoking
Exercise
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Heart muscles strengthen, allowing more blood to be
pumped with each beat.
Blood pressure may decrease.
HDL levels may increase.
Stress levels may lower.
Diet
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To reduce your risk of cardiovascular disease, limit your
intake of fried or processed foods and of foods made
from animal products.
Avoid Smoking

Tobacco products damage blood vessels and contribute
to the development of atherosclerosis and hypertension.
Acknowledgements
Prentice Hall Health Book
 Google.com/images
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