The
Cardiovascular
System
Did You Ever Wonder
How Penicillin Works?
Penicillin is an antibiotic medicine that
works by preventing bacteria from building
new cell walls when they divide.
How Does Penicillin Travel
through Your Body?
Through your
Cardiovascular System
The Cardiovascular System
has 5 Components
1.
2.
3.
4.
5.
Arteries
Blood Vessels
Capillaries ( tubes that carry blood )
Veins
Heart
(a pump)
Blood
Three Types of Blood Vessels
• There are three types of vessels (tubes)
that blood flows through.
• Arteries – carry blood away from your
heart
• Veins – carry blood in toward your heart
• Capillaries – tiny vessels carry blood to all
your cells
Arteries
• Arteries are strong, flexible blood
vessels that carry blood from the
heart to the rest of the body.
• They expand to accept the blood
pumped into them with each beat of
the heart, and contract when the
heart relaxes.
• As the arteries become smaller and
narrower they turn into capillaries.
Capillaries
• are the smallest
blood vessels
…some capillaries
are so narrow that
only one red blood
cell can fit through
at a time!
• Capillaries
connect arteries
and veins.
Capillaries
Veins
Arteries
Capillaries
Capillary beds carry blood to
all the cells in your body
vein
artery
A Capillary’s Job
• Nutrients, oxygen (O2) and other
substances must leave your blood to get to
your body’s cells.
• Capillary walls are only one cell thick so
these substances can pass through to get
to your body’s cells.
• When your cells are done with these
substances, waste products such as
carbon dioxide (CO2) leave the cells, pass
through the capillary walls and enter
the blood to be carried away from the cells.
What happens in each capillary?
4) Blood
from the
capillary
enters a
vein
3) CO2 and waste
products leave the cells
and enter the capillary
2) Oxygen and nutrients
leave the capillary and
enter the cells
1) Blood
from an
artery
enters
the
capillary
Example:
• Capillaries surround alveoli in the lungs
• This is where the blood gives up carbon
dioxide and picks up oxygen
Veins
• Veins carry blood toward
the heart.
• Veins are less elastic (less
stretchy) than the arteries.
• Veins have valves that
open to let blood through
and close to prevent blood
from flowing backward
due to the pull of gravity.
• Varicose veins are caused
by weakened valves that
allow blood to flow
backward and pool inside
the vein, causing a bulge.
Amazing Heart Facts
• The aorta, the largest artery in the body, is
almost the diameter of a garden hose.
• Capillaries are so small that it takes 10 of
them to equal the thickness of a human hair.
• Give a tennis ball a good, hard squeeze.
You're using about the same amount of
force your heart uses to pump blood out to
the body. Even at rest, the muscles of the
heart work hard—twice as hard as the leg
muscles of a person sprinting.
Your Heart’s Job
• Your heart is a double pump
• It is an organ made of cardiac muscle
• It pumps blood throughout your body
–To the lungs to pick up oxygen
–To your body to supply your body’s
cells with oxygen and other
important substances
Blood Flow
• The following slides will follow the
path of blood through the heart.
• Keep in mind, this is a one-way flow
• In medical diagrams, the left and
right are labeled from the patient’s
point of view.
• What looks like your left on the
diagram is really the patient’s right.
As you view the following slides:
• Color the arrows on the heart
diagram indicating the direction of
blood flow
• Use blue to indicate de-oxygenated
blood.
• Use red to indicate oxygenated
blood.
De-oxygenated blood enters
the right atrium
Through the
Superior
Vena Cava
Through the
Inferior Vena
Cava
Right
Atrium
De-oxygenated blood passes
through the Tricuspid Valve into
the Right Ventricle
Right
Ventricle
The blood is pumped from the
right ventricle through the
pulmonary artery into the lungs
The blood picks up oxygen
in the lungs then heads into
the left atrium
Left
Atrium
Aorta
The oxygen-rich blood
is pumped into the
left ventricle then out
through the aorta to
the body
Left
Ventricle
Notice that the path of
this blood travels
under the pulmonary
artery
Label your Human Heart Diagram
1. Aortic valve
2. Superior vena
cava
3. Right atrium
4. Pulmonary valve
5. Tricuspid valve
6. Inferior vena
cava
7. Right ventricle
8. Aorta
9. Pulmonary artery
10. Left atrium
11. Pulmonary vein
12. Bicuspid (Mitral)
valve
13. Left ventricle
14. Septum
Key Terms
Blood Vessels
– Arteries
• Including the aorta
and pulmonary
artery
– Veins
• including the Vena
cava (superior and
inferior) &
pulmonary vein
– Capillaries
Heart Chambers
– Right atrium
– Left atrium
– Right ventricle
– Left ventricle
Heart Valves
– Tricuspid valve
– Pulmonary valve
– Mitral valve
– Aortic valve