THE CARDIOVASCULAR SYSTEM:

North American Health Concept

Heart disease in North America is a leading cause of
death for men and women. Heart disease was once
thought to affect men much more often than women, but
this has changed dramatically over the past 50 years,
affected by the changing lifestyles of women. Coronary
artery disease, commonly known as “hardening of the
arteries,” is a common disease/disorder of the
cardiovascular system. It often leads to angina and to
myocardial infarction. Many cases of cardiovascular
diseases can be prevented. To maintain a healthy heart,
physicians recommend limiting salt intake, quitting
smoking, and eating a healthy diet full of fruits,
vegetables, grains, fish, meats, and dairy products that
are low in fat. In addition, a healthy weight and lifestyle
should be maintained through inclusion of a program of
regular exercise. Personal health promotion activities
should include stress reduction exercises that help us
cope with the increasingly busy and stressful demands of
life in the 21st century.
The cardiovascular system or circulatory system?
The cardiovascular system is sometimes also referred to
as the circulatory system, although they are not quite the
same thing. The term cardiovascular speaks to the two
parts of the system: cardio meaning heart and vascular
meaning vessels. Anatomically, the major structures are
the heart and blood vessels (arteries, veins, capillaries),
but it is difficult to think of this system without including
reference to the lungs (part of the respiratory system).
The main function of the cardiovascular system is to
distribute blood through blood vessels throughout the
body. The main function of the heart is to pump the blood
(to function as the engine of the cardiovascular system),
beginning the process of circulation.
The cardiovascular system: Anatomy and
Physiology
The heart consists of myocardial tissue and is divided into
four chambers: two atria and two ventricles. The left and
right atria are the two upper chambers of the heart, the
left and right ventricles the two lower chambers. Blood
that is high in oxygen (oxygenated) flows into the left
atrium from the lungs through the pulmonary veins. The
left atrium then contracts to pump a supply of blood to
the left ventricle. The aorta is found in the left ventricle. It
branches into a complex series of arteries that bring
oxygenated blood to all of the organs of the body. When
the blood reaches the capillaries, it delivers oxygen and
in exchange picks up the waste product carbon dioxide to
carry away through veins back to the heart. This blood in
the veins empties first into the vena cava (the main vein
in the human body), which then carries it to the right side
of the heart. Next, this blood is pumped through the
pulmonary artery to the lungs where it exchanges the
carbon dioxide waste for a new supply of oxygen. The
cycle then repeats. This cycle is powered by the
contraction of the heart, which is caused by electrical
impulses within the heart. The contraction of the heart is
known as the heartbeat. The circulatory system is a
subsystem of the cardiovascular system. It concerns itself
with blood and the function of blood, but it is difficult to
think of the circulatory system without thinking about the
lymphatic system. They are essential to each other.
Lymph cells assist in cleansing the blood of dead cells
and bacteria. Blood is the mode of transport for lymph,
nutrients, hormones, electrolytes, gases (oxygen and
carbon dioxide), water, and wastes to and from cells. The
capillaries are the site of this exchange between the
blood and the tissues that surround them. Blood also
helps stabilize body temperature and the natural pH
balance.
In summary, the cardiovascular system is most often
thought of in terms of the heart, blood vessels, and the
lungs. The circulatory system is most often thought of as
the blood vessels, blood, lymph, and the heart.
Physiology Of The Pulse
When the left ventricle of the heart contracts, it forces
blood into the aorta and from there a wave of blood
surges through the arteries. This wave is called a pulse.
Pulse is measured in beats per minute (bpm). The pulse
can be palpated at various sites on the body where an
artery crosses over a bony prominence. A tachycardia
and a bradycardia are examples of variations in rate. In
each of these cases, the rhythm of the pulse is referred to
as irregular, meaning the interval between each beat is
not equal in length.
Blood pressure
Blood pressure refers to the pressure of the blood within
the arteries. When the left ventricle of the heart
contracts, blood is forced out into the aorta and travels
through the large arteries to the smaller arteries,
arterioles, and capillaries. When the left ventricle
contracts and pumps blood into the aorta, force is
exerted on the arterial wall. This force is referred to as
systolic pressure. When the heart is in the process of
filling, the ventricle relaxes. The change in arterial
pressure that results as the ventricle relaxes is called the
diastolic pressure. Blood pressure is assessed using a
sphygmomanometer. This piece of equipment is
commonly called a blood pressure cuff or cuff. Blood
pressure is measured in millimeters of mercury (Hg). It is
usually stated as a fraction— systolic over diastolic—as in
110 over 70. t is also written in fraction form, 110/70.

Congestive Heart failure

Heart failure, also known as congestive heart failure, is a
condition that develops when your heart doesn't pump
enough blood for your body's needs. This can happen if
your heart can't fill up with enough blood. It can also
happen when your heart is too weak to pump properly. A
myocardial infarction, or heart attack, often decreases
the strength of contraction of the left ventricle of the
heart so that the heart fails to pump effectively. The
etiology of a myocardial infarction (MI) may include
coronary artery disease (CAD), heart valve disease,
hypertension, or a combination of these factors. When
the left ventricle of the heart is damaged and not able to
pump blood efficiently, the vessels in the lungs become
edematous. This leads to pulmonary congestion.
This leads to pulmonary congestion. A plasma leak into
the alveoli and bronchial walls results when excessive
back pressure in the capillaries of the lungs co-occurs.
This is the condition of pulmonary edema. It interferes
with normal oxygen and carbon dioxide exchange. A
diagnosis of congestive heart failure is made in the
presence of pulmonary congestion and pulmonary edema
associated with heartrelated causes.
Angina And Myocardial Infarction
Angina is a type of chest pain. It is caused by a narrowing
of the arteries. Sometimes when the heart is asked to
pump harder in response to physical or emotional stress,
the coronary arteries cannot supply enough oxygen to
the heart muscle. The result can be chest pain or angina
pectoris. When the heart is deprived of oxygen for too
long, a myocardial infarction occurs. Oxygen-deprived
cells die. Again, chest pain is experienced. An MI (heart
attack) is usually caused by a progressive narrowing of
the coronary arteries. Blockage or occlusion of an artery
can occur suddenly. It may be the result of a thrombus or
an embolus.