Download CIRCULATORY SYSTEM

CIRCULATORY SYSTEM
Mr. Z’s Cool Science Classes
CATALYST
• The remainder of the unit is on the
CIRCULATORY AND RESPIRATORY
Systems. How are they related?
Functions of the Circulatory System
• Organisms composed of a small # of cells do not
need a circulatory system.
• Why?
• B/c Oxygen, nutrients, and waste products can
easily diffuse back and forth across cell
membranes
• THE HUMAN CIRCULATORY SYSTEM
CONSISTS OF THE HEART, A SERIES OF
BLOOD VESSELS, AND THE BLOOD THAT
FLOWS THROUGH THEM.
Functions of the Circulatory System
• Larger organisms, however, cannot rely on
diffusion.
• Most of their cells are not in direct contact
with the environment, and substances in
one part of the organism may be needed
in another part.
3 COMPONENTS OF
CIRCULATORY SYSTEM
• HEART
• BLOOD VESSELS
• BLOOD
HEART
• YOUR HEART IS
COMPOSED
ALMOST ENTIRELY
OF MUSCLE, IS A
HOLLOW ORGAN;
ABOUT THE SIZE
OF YOUR
CLENCHED FIST.
HEART
• The heart is enclosed by a protective tissue
called the pericardium.
• Myocardium- ( myo-greek meaning muscle,
kardia meaning heart) a thick layer of muscle
that contracts to pump blood through the
circulatory system.
• If Itis means “inflammation,” what does
myocarditis mean?
HOT QUESTION?
• If Itis means “inflammation,” what
does myocarditis mean?
• INFLAMMATION OF THE HEART
HEART
• ATRIUM (atria plural) - upper chamber
that receives blood
• VENTRICLE- lower chamber, which
pumps blood out of the heart
• The heart has 4 chambers– 2 atria and 2
ventricles.
The Heart
• Blood could not help the body if it
didn’t flow.
• Blood flows because the circulatory
system has a pump – the heart.
• The heart forces blood to move all over
the body.
• Keeping fit, not smoking, and eating
food low in animal fats will reduce the
risk of diseases that affect the heart
Circulation Through the Body
• The heart functions
as 2 separate pumps.
• Pulmonary Circulation
-Right Side pumps
blood from heart to
lungs
• Systemic Circulation Oxygen-rich blood
flows into left side of
heart and to rest of
body.
Circulation through the Heart
• Valves-there are flaps of connective tissue
between the atria and the ventricles.
• Blood moving from the atria holds the valves
open. When the ventricles contract, the valves
close, which prevents blood from flowing back
into the atria.
• This system of valves keeps blood moving
through the heart in one direction, like traffic on
a one way street.
HOT QUESTION!!!
• What is the function of the heart valves?
• The function of the heart valves is to
prevent any backflow of blood from the
ventricles to the atria
“lub-dub”
• Throughout a
lifetime, the
average person’s
heart beats about 3
billion times!!!!!
• To do all that work,
the
heart
requires
a
3,000,000,000
lot
of
oxygen!
times!
BLOOD VESSELS
• AORTA-large blood vessel, which is the st
of a series of blood vessels that carry the
blood on its round trip through the body
and back to the heart.
• As blood flows through the circulatory
system, it moves through 3 types of blood
vessels—arteries, capillaries, and veins.
1. Blood returning to the heart is low in oxygen.
– This blood is pumped through the right side of the
heart into arteries that lead to the lungs.
2. As blood flows through the capillaries in the
lungs, it picks up oxygen and gets rid of
waste.
3. Leaving the lungs, the blood travels through
veins, back to the heart.
– Blood returning to the heart from the lungs is ready
to deliver oxygen to the rest of the body.
• Oxygen-rich blood is
pumped through the left
side of the heart and out
the aorta, the largest
artery in the body.
• From the aorta , blood
flows to all parts of the
body through a
system of increasing
smaller arteries.
• The smallest of the
blood vessels are the
capillaries.
Capillaries are the side streets and alley of the circulatory
system.
The walls are only one cell thick! And, most are so narrow
that blood cells must pass through them in single file.
The real work of the circulatory – bringing oxygen to the
tissues and gathering carbon dioxide and other waste
products from them – is done in the capillaries.
Once blood has passed through the capillary system, it
must be returned to the heart. This is the job of veins.
Pulse
• Each time your heart
beats, it pumps the blood
through your arteries and
you can feel it. It is called
a pulse.
• You can feel your pulse
where your arteries are
close to the surface of
your skin.
• Gently place two fingers
(not your thumb!) on the
side of your neck or on the
inside of your wrist or
elbow.