Transcript cardiovascular fitness- the circulatory system

THE CIRCULATORY SYSTEM
Health Science 1
WHAT ARE THE FUNCTIONS OF THE
CIRCULATORY SYSTEM ?
•Circulates blood through the body
•Transports water, oxygen and food to cells and
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, also 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.
THE HEART AS A DOUBLE
CIRCULATORY PUMP.
BLOOD VESSELS
There are 3 vessel types:1.Arteries
2.Veins
3.Capillaries
ARTERIES
The wall of the heart is supplied with blood
from two small vessels called the coronary
ARTERIES. These can be blocked by blood
clots and when this happens blood supplied to
part of the heart wall is cut off, resulting in
sudden death.
The structure of ARTERIES, VEINS and
CAPILLARIES is different.
The ARTERIES have a relatively thick wall.
Most ARTERIES and ARTERIOLES (very small
arteries) carry oxygenated blood away from
the heart.
They pulsate as the heart beats.
They 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
VEINS carry de-oxygenated blood to the
heart.
They have much thinner walls than arteries.
They contain many VALVES which keep deoxygenated blood flowing to the heart and
avoid the possibility of blood flowing
backwards.
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.
Any vessel ENTERING the heart is called a
VEIN.
CAPILLARIES
CAPILLARIES are vessels that link the
ARTERIES with the VEINS.
At one end they carry oxygenated blood which
transfers supplies of oxygen and nutrients to
the muscles.
At the other end CAPILLARIES pick up waste
and so carry de-oxygenated blood into 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 which raises BLOOD
PRESSURE.
Other conditions associated with smoking
include 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 ?
If you go to a doctor for a check up, you are
very likely to have your blood pressure
checked.
WHAT IS BLOOD PRESSURE ?
As you get older the blood vessel walls become
less elastic and the small vessels do not
expand to let through the blood pumped from
the heart.
This means that resistance to the flow of
blood is increased and this means that blood
pressure rises.
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
Epidemiology I
Epidemiology
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The most common primary diagnosis in the United States, 50 million
American affected.
Only 70% are aware they have HTN
Of those aware of their HTN, only 50% are being treated.
Only 25% of all hypertensive patients have their BP under control
HTN is a risk factor for coronary artery disease (CAD), congestive
heart failure (CHF), stroke, and renal failure
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.
Management of
Hypertension
Prevention
Patient education
Life-style modification
Medication
6. Exercise regularly- this will help to control
stress, keep your blood pressure normal and
your whole system in good shape.
REVISION
Heart
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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
The Effects of Aging on
the Cardiovascular
System
Age-Related Changes
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Less efficient contraction
Decreased elasticity of the arteries and
veins
Proper diet and regular exercise can
help to keep the cardiovascular system
healthy
Disorders of the
Cardiovascular System
Types of Disorders
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Disorders of the blood
– Anemia
– Leukemia
– Bleeding disorders
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Disorders of the blood vessels
– Atherosclerosis
– Venous disorders
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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:
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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
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Cor pulmonale (right-sided heart failure)
Congestive heart failure (left-sided heart failure)
– Treated with medication; fluid intake may be restricted
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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
Cardiac Rehabilitation
Focus of Cardiac Rehabilitation
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Help the person to regain strength and
adopt heart-healthy habits
Help the person to begin an exercise
program designed to strengthen the
heart muscle and make it a more
effective pump
Help the person to learn healthy
dietary changes
Provide supportive emotional therapy