Transcript Circulatory system pp

Organ Systems
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The circulatory
system
What is the purpose of the
circulatory system?
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The purpose of the
circulatory system is to:
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Transport nutrients and
oxygen to all the cells of
the body.
Transport wastes and CO2
away from the cells to be
excreted.
Transport hormones.
Work with immune system
to fight off infections.
What are the components of the
circulatory system
There are three major
components of the
circulatory system.
1. Blood
2. Blood vessels
3. The heart
The Blood
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There are four major components of the
blood. Each plays a very specific role.
The components are:
Red Blood Cells
 White Blood Cells
 Platelets
 Plasma
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Red Blood Cells
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Red blood cells are red
because they contain the
molecule Hemoglobin.
Their primary responsibility is
to carry oxygen to the cells,
and carry CO2 away from the
cells.
Red blood cells have no nuclei.
Red blood cells are created in
your bone marrow.
Sometimes they are referred
to as Erythrocytes.
White Blood Cells
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The white blood cells
function to help your
body fight off infections.
There are different types
of white blood cells, but
they all work towards the
same purpose.
Sometimes white blood
cells are referred to as
Leukocytes or
lymphocytes.
Plasma
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Plasma is the liquid portion of your blood,
and it is made up mostly of water.
Dissolved nutrients and wastes are carried
along by the plasma.
Hormones are also trasported through
your body in the plasma.
Platelets
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Platelets are the smallest portion of your blood.
Platelets are responsible for repairing breaks in
your blood vessels.
The secrete a stickly protein called fibrin, which
helps to clot blood at the site of a break.
This is an example of a positive feedback
mechanism.
This clot solifies in air and becomes a scab.
Blood Types
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Not everybody has the same type of blood.
Proteins present on our red blood cells determine if we
have type A, B, AB or O blood.
The presence of absence of another protein determine if
we are “+” or “-”.
We will do a lab to investigate blood types and
transfusions tomorrow.
The Blood Vessels
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There are 3 major types of blood vessels,
and 2 intermediate types.
The major types are
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Arteries
Veins
Capillaries
Blood Vessels (cont.)
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The two intermediate
types are called
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Arterioles: Vessels
that link arteries to
capillaries..
Venuoles: Vessels
that link capillaries to
veins.
Blood vessels
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Arteries are the blood vessels
that carry blood away from the
heart.
They are the thickest and most
muscular of all blood vessels.
They need to be able to
expand with each beat of the
heart. We are familiar with
this as our pulse.
The largest blood vessel in the
body, the Aorta, is considered
an artery.
Except for the pulmonary
artery, all arteries carry
oxygen rich blood which has a
bright red color.
Blood vessels
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Veins are the only blood
vessels that have valves
in them.
The valves are there to
stop the back flow of
blood in your blood
vessels.
Veins carry blood back to
the heart.
Except for the pulmonary
veins, all veins carry
oxygen poor blood that is
a dark red color.
Question
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Which blood
vessels do you
think technicians
use when you
make a donate
blood at a blood
drive?
Blood vessels
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The capillaries are the smallest and most
abudant of blood vessels in your body.
It is through the very thin walls of the
capillaries that all diffusion and osmosis
occurs.
Capillaries pick up nutrients through the
capillaries surround the S.I., and oxygen
through the alveoli in the lungs.
Arterioles and Venuoles
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These vessels are simply smaller versions
of arteries and veins.
Their job is the connect larger arteries and
veins to the capillaries.
Arterioles have the same characteristics as
arteries and venuoles have the same
characteristics of veins.
The heart
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The heart is a fist-sized muscular organ
that is found in the center of your thoracic
cavity (Chest).
It is surrounded by a thin protective
membrane called the pericardium.
The heart is protected by the rib cage.
The heart
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The human heart consists of four chambers. In
order the blood flows from:
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The right atrium
The right ventricle
After a round trip to the lungs…
The left atrium
The left ventricle
And then through the Aorta to all the blood vessels in
the body.
Superior vena cava
Pulmonary Vein
Circulation.
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The heart actually consists of two pumps,
the right and left ventricles.
The right ventricle pumps the blood to the
lungs and back. This is called pulmonary
circulation.
The left ventricle pumps the blood to the
entire body and back. This is called
systemic circulation.
Pulmonary circulation
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Blood enters the Right Atrium.
It passes through the tricuspid valve into the
Right Ventricle.
The Right ventricle pumps blood into the
pulmonary arteries.
The pulmonary arteries carry blood to the lungs.
In the lungs, the blood flows into the capillaries
surrounding the alveoli. It is here the blood
picks up O2 and drops off CO2
Pulmonary circulation cont.
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The now oxygenated blood flows from the
capillaries into veins and then into the
pulmonary veins.
The pulmonary veins carry the blood back
into the heart at the left atrium.
This concludes pulmonary circulation, and
we begin systemic circulation.
Systemic circulation
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O2 rich blood enters the left atrium.
The blood passes through the mitral valve
and enters the left ventricle.
The left ventricle pumps blood into the
aorta.
The blood flows from the aorta into
arteries.
The arteries flow into arterioles.
Systemic circulation cont.
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The blood then flows into the capillaries.
It is here in the capillaries that all diffusion
occurs. Nutrients, which were picked up
near the S.I. and O2 from the lungs are
delivered to all the cells in the body.
Wastes and CO2 pass from the cells to the
blood.
The blood now flows into venuoles.
Systemic circulation cont.
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The blood now enters the veins.
The veins then flow into the vena cava. There
are two of these.
The superior vena cava collects all the blood
from the top part of your body, the inferior vena
cava from the lower part.
The vena cava delivers the blood to the right
atrium. Systemic circulation is complete.