Hi Everyone !!!

The next e-mails , I will focus on the Circulatory System and how
important it is to our body and health ! But for now, get to know
what it is ....where it is....what's in it !!!!!

The Circulatory System

Circulatory System, or cardiovascular system, Heart + Blood Vessels +
Blood in humans, is really the combined function of the heart, blood,
and blood vessels to transport oxygen and nutrients to organs and
tissues throughout the body and carry away waste products.
How does it function?
1)It increases the flow of blood to meet increased energy demands
during exercise and regulates body temperature.
2) It protects the body from foreign substances or organisms that
invade the body, by way of the blood's immune system, such as
white blood cells and antibodies, which are sent to regions under
attack.
3)Also, in the case of injury or bleeding, the circulatory system
sends clotting cells and proteins to the affected site, which quickly
stop bleeding and promote healing.

II. Components of the Circulatory System



The heart is the engine of the circulatory system.
It is divided into four chambers:
1) right atrium,
2) the right ventricle,
3) the left atrium
4) the left ventricle.
The walls of these chambers are made of a special muscle called
myocardium, which contracts continuously and rhythmically to pump
blood.
Two stages for each heart beat:
1)diastole, when the heart is at rest
2) systole, when the heart contracts to pump deoxygenated blood
toward the lungs and oxygenated blood to the body.
During each heartbeat, typically about 60 to 90 ml (about 2 to 3 oz)
of blood are pumped out of the heart. If the heart stops pumping,
death usually occurs within four to five minutes.
That is why, it is very important to know the warning signs of
impending heart attack :
1 )Crushing or even vague pain on mid chest unrelated or related to
exercise
2)feeling of indigestion
3)pain/ numbness radiating to LEFT ARM
3) sweating, feeling of impending doom
4)WHAT TO DO ? CPR ….HAVE SOMEONE CALL 911 IMMEDIATELY !!!!!!
THE
PARAMEDICS will arrive in 3-5 minutes in most cases and can check the
heart rhythm right away by connecting to a monitor- in that case,
they will know what the heart is doing ; THEY HAVE THE GADGETS –
they
can "defibrillate" or send electrical shocks to the heart
hopefully
to convert the heart rhythm right away ……or simply inject life
saving drugs to the heart …….en route to the emergency room
…….OXYGEN….CPR……NEVER DRIVE SOMEONE IF HAVING SYMPTOMS
OF HEART
ATTACK ! This will decrease their chances of getting enough
oxygenation and help.

Blood consists of three types of cells:
1)rbc'S OR red blood cells - CARRIES OXYGEN !!!!!
2) wbc's or white blood cells – fights diseases
4) platelets – responsible to clot your blood, so you won't
bleed to death! ALL of which are carried through blood vessels in a
liquid called plasma. Plasma is yellowish and consists of water,
salts, proteins, vitamins, minerals, hormones, dissolved gases, and
fats.

Three types of blood vessels form a complex network of tubes
throughout the body.
1)Arteries carry blood away from the heart
2) veins carry it toward the heart.
3)Capillaries are the tiny links between the arteries and the veins
where oxygen and nutrients diffuse to body tissues.
The inner layer of blood vessels is lined with endothelial cells that
create a smooth passage for the transit of blood. This inner layer is
surrounded by connective tissue and smooth muscle that enable the
blood vessel to expand or contract. Blood vessels expand during
exercise to meet the increased demand for blood and to cool the body.
Blood vessels contract after an injury to reduce bleeding and also to
conserve body heat.

Arteries have thicker walls than veins to withstand the pressure of
blood being pumped from the heart. Blood in the veins is at a lower
pressure, so veins have one-way valves to prevent blood from flowing
backwards away from the heart. Capillaries, the smallest of blood
vessels, are only visible by microscope—ten capillaries lying
side by
side are barely as thick as a human hair. If all the arteries, veins,
and capillaries in the human body were placed end to end, the total
length would equal more than 100,000 km (more than 60,000
mi)—they
could stretch around the earth nearly two and a half times.

The arteries, veins, and capillaries are divided into two systems of
circulation: systemic and pulmonary.
1)The systemic circulation carries oxygenated blood from the heart to
all the tissues in the body except the lungs and returns deoxygenated
blood carrying waste products, such as carbon dioxide, back to the
heart.
2)The pulmonary circulation carries this spent blood from the heart
to the lungs. In the lungs, the blood releases its carbon dioxide and
absorbs oxygen. The oxygenated blood then returns to the heart before
transferring to the systemic circulation.


MARIA VILLARTA , RN