The Circulatory System
The Heart
Vocabulary Woo-Hoo!
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Myocardium
Atrium
Ventricle
Valve
Aorta
Artery
Capillary
Vein
What Factors Affect Heart Rate?
• Make a list of things that might affect how fast your heart beats…
• Can we test any of them right now?
• Mini-Lab
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Write the Question:_________________________________________
Write a Hypothesis: _________________________________________
Experiment!
Record Data
Results-Make a graph
Conclusion-what happened? Were you right?
The Circulatory System
The human circulatory system consists of the
heart, blood vessels, and blood.
The Heart
• Your heart is about the size of your fist and is slightly to the left of
your sternum.
• It is made of mostly muscle
• The heart is enclosed in a sac of tissue called the pericardium
• The myocardium is a thick layer of muscle that causes the heart to
pump.
• The heart pumps on average 72 times per minute
• During one year the average person pumps enough blood to fill an
Olympic size swimming pool!
Valves—like gateways from one
chamber to another or the
ventricles to the arteries, the
valves keep blood from going
backwards. Valves keep blood
flowing in the right direction.
Right Atrium—receives
deoxygenated blood from
the body
Right Ventricle– receives
blood from atrium above
and pumps blood to the
lungs through the
pulmonary artery
Left Atrium—the upper
chamber, receives blood
from the lungs and pumps it
into the lower chamber.
Left Ventricle—receives
blood from atrium above it,
pumps oxygen rich blood
into the Aorta and out to the
body.
Color and Label the Heart Diagram
Pulmonary Veins
Left Atrium
Left Ventricle
Aortic Valve
Mitral Valve
Aorta
Right Atrium
Right Ventricle
Pulmonary Artery
Superior Vena Cava
Inferior Vena Cava
How the Heart Works Animation Video
• 5 facts!!
Your Heartbeat
• When the muscle fibers in your atria and
ventricles are stimulated (by the Sinoatrial
node), the atrial muscles contract followed by
the ventricle muscles (the 2 step pattern = lub
dub rhythm)
• Your heart will beat faster or slower depending
on your body’s need for exercise (more
oxygen=faster and more beats per min)
Arteries have thick walls
to withstand the
pressure
Smallest of the blood
vessels
Narrow walls, delivers
the oxygen and
nutrients to the tissues
Veins
Large vessels that carry
blood from the heart to
tissues of the body
supplying oxygen
Capillaries
Arteries
Blood Vessels
As blood flows through the circulatory system it moves
through three types of blood vessels—arteries,
capillaries, and veins
Once the blood has
passed through the
capillary and no longer
has oxygen it goes back
to the heart in the vein
Once in the heart it can
be pumped to the lungs
for more oxygen
Veins have valves to
keep the blood moving
to the heart
Circulation
Blood Pressure
•Your heart produces pressure
•The force of the blood on the walls of
the arteries is known as BLOOD
PRESSURE
•Without pressure, blood would stop
flowing
Diseases of the Circulatory System
High Blood Pressure
• Aka Hypertension
• Heart works harder
• Can cause heart
attack or stroke
Atherosclerosis
• Fatty deposits called
plaque build up on
the inner walls of
the arteries
• If the artery is
blocked, oxygen
cannot make its way
to the body or the
heart=heart attack
Valve Problems
• Can be damaged
due to disease or
birth defects
• Causes blood to
flow backwards or
inefficiently
• Lack of oxygen to
the body
Do you have a Heart Murmur? What is it?
What is a Heart Attack??
Case Study—A look at Long QT
Answer the following during the
first video Clip1. What is the electrical activity of
the heart responsible for?
2.
Briefly describe what happened
to Kevin Oill.
3.
How does a defibrillator work?
4.
What evidence did the medical
team use to diagnose Kevin's
Long QT Syndrome?
Answer the following during the
second video Clip1. How was Kevin's disorder
treated with technology?
2.
What did Dr. Zipes mean by the
phrase "umbilical cord attached
to medical therapy?"
3.
What are pacemakers? How
have they evolved? What are
the pros and cons of living with
a pacemaker?