Transcript File the circulatory system

THE CIRCULATORY SYSTEM
Health Science 1
Marta Valdes, Instructor
WHAT ARE THE FUNCTIONS OF THE
CIRCULATORY SYSTEM ?
•Circulates blood through the body
•Transports water, oxygen and food to cells
• Removes wastes from the cells.
•Helps fight disease
•Helps maintain the correct body temperature
THE HEART
The heart is a muscular pump. It is located in the
center of chest slightly tilting to the left.
It is divided into two halves by a central partition
called the SEPTUM.
Each half is then, divided by valves into an ATRIUM
above (A for above) and a VENTRICLE below.
We, therefore have a right and left ATRIUM and a
right and left VENTRICLE.
Heart

Walls of the heart are made up of three layers of
tissue:
– Endocardium
– Myocardium
– Epicardium
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Atria and ventricles
Heart valves
Conduction system
Coronary circulation
BLOOD VESSELS
There are 3 vessel types:1.Arteries
2.Veins
3.Capillaries
The structure of ARTERIES, VEINS and
CAPILLARIES is different.
ARTERIES
• ARTERIES have thick walls.
• Most carry oxygenated blood away from the
heart.
• Pulsate as the heart beats.
• Are more elastic than VEINS and also have
higher pressure.
The PULMONARY ARTERIES are different,
they carry de-oxygenated blood from the
heart to the lungs.
Any vessel
LEAVING
the heart is
called an
ARTERY.
VEINS
• Any vessel ENTERING the heart is called a
VEIN.
• They have much thinner walls than arteries.
• VEINS carry de-oxygenated blood to the
heart.
• They contain many VALVES which keep deoxygenated blood flowing to the heart and
avoid the possibility of blood flowing
backwards.
VEINS
• VEINS rarely pulsate.
• They are less elastic than arteries.
• They carry blood at a lower pressure.
The PULMONARY VEINS, which leave the
lungs on the way to the heart, are different
from other veins, they carry oxygenated blood.
CAPILLARIES are vessels that link the ARTERIES with the VEINS.
TO SUM UP THE DIFFERENCES BETWEEN CAPILLARIES, VEINS AND ARTERIES
SMOKING
The ARTERIES need to be clear and free from
obstruction in order to carry blood and
supplies to the working muscles.
But these passageways can be blocked by lipids
which can be caused by smoking.
Nicotine, one of the main components of
tobacco, affects the nervous system, which
controls the HEART RATE.
HEART RATE increases
raises BLOOD PRESSURE.
Other conditions associated with smoking
include Coronary Heart Disease (CHD) and
STROKES.
It is said that risk of a heart attack is
decreased after the smoker has stopped
smoking for one year.
WHY DO WE NEED TO TAKE OUR BLOOD PRESSURE ?
Blood pressure varies with:
1. AGE
2.GENDER
3.ALTITUDE
4.MUSCULAR DEVELOPMENT
5.STRESS
6.TIREDNESS
Guidelines
The Seventh Report of the Joint National Committee
on Detection, Evaluation, and Treatment of High
Blood Pressure (JNC VII) uses the following
guidelines to define HTN in adults: (Brashers, 2006,
Category
Systolic
Diastolic
p.1)
Normal
Pre-hypertension
and
120-139 or
<120
<80
85-89
Stage 1
hypertension
140-159
or
90-99
Stage 2
hypertension
>160
or
>100
What can I do to reduce the
risk of high blood pressure ?
1. Check your weight
2. Limit your alcohol consumption
3. Avoid smoking
4. In some people too much salt may unbalance the
body chemistry and affect blood pressure.
5. Avoid situations that cause stress, anxiety or
worry.
6. Exercise regularly- this will help to control stress,
keep your blood pressure normal and your whole
system in good shape.
Management of
Hypertension
Prevention
Patient education
Life-style modification
Medication
The Effects of Aging on
the Cardiovascular
System
• Less efficient contraction
• Decreased elasticity of the arteries & veins
•Proper diet and regular exercise can help to
keep the cardiovascular system healthy
Disorders of the Cardiovascular System
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Disorders of the blood
– Anemia
– Leukemia
– Bleeding disorders
Disorders of the blood vessels
– Atherosclerosis
– Venous disorders
Disorders of the heart
– Coronary artery disease
– Heart failure
– Conduction disorders
Disorders of the Blood Vessels
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Atherosclerosis
– Blocking of the arteries
– Plaques build up on the inside of the
arteries, restricting blood flow
– Can lead to myocardial infarction (heart
attack), stroke
– Risk factors: high blood cholesterol, lack
of exercise, smoking
Disorders of the Blood Vessels
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Venous disorders
– Venous thrombosis: blood clots form in
the veins; danger of embolism
– Venous (stasis) ulcers: skin breakdown as
a result of poor circulation
Risk Factors for Cardiovascular Disease
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Nonmodifiable cardiac risk factors
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Age
Gender
Heredity
Body build
Modifiable cardiac risk factors
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Smoking
Inactivity
Obesity
High-cholesterol diet
Heart Disease
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Coronary artery disease
– Disease of the arteries that supply the heart with oxygen
and nutrients
– Two closely related conditions:
 Angina pectoris: pain that occurs when heart muscle is
deprived of oxygen
 Myocardial infarction: heart attack; part of the heart
muscle dies
Heart failure
– Heart is unable to pump enough blood to meet the body’s
needs
– Types
 Cor pulmonale (right-sided heart failure)
 Congestive heart failure (left-sided heart failure)
– Treated with medication; fluid intake may be restricted
Conduction disorders
– Electrical impulses that cause the heart to contract cannot
get through
Electrocardiography
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In this test, sensors are attached to
the person’s chest
Tracing of electrical activity of the
heart on paper is called an
electrocardiogram (EKG, ECG)
Stress test: EKG obtained while a
person exercises
Echocardiography
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In this test, sound waves are bounced
against the body to produce an image
Provides information like:
– Size and shape of the heart
– Its pumping strength
– The location and extent of any damage to
its tissues
Doppler Ultrasound and Radiography
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Doppler ultrasound: sound waves are
used to check the blood flow in the
large arteries and veins of the arms
and legs
Radiography: Allows the doctor to see
the heart and vessels without actually
entering the body