Download The Heart

The Heart
Did you know?
 The heart beats 100000 times in a day,
pumps 4000 liters of blood to around
1000000 km of blood vessels. In a day!!!
 The heart can continue to beat even
when separated from the body
 heart beating
 Doctors have long known that mornings
are the prime time for heart attacks.
 The Male heart weighs 10 ounce and the
female heart 8 ounce.
 The heart starts beating at 4 weeks after
conception
 People who are optimistic suffer fewer
heart attacks and stroke and have a 55
percent less chance of suffering
cardiovascular diseases
Location of the Heart
 The heart is located
between the lungs behind
the sternum and above the
diaphragm.
 It is located in the center of
the chest surrounded by
the pericardium.
 Its size is about that of a fist,
and its weight is about 250300 g.
Coronary arteries –blood
supply to the heart
Structure of the human
heart
 The walls of the
heart are composed
of cardiac muscle,
called myocardium.
 Layers (peri, myo,
endo---cardium)
 It consists of four
compartments/cha
mbers
 the right and left atria
and ventricles
The Heart Valvesatrioventricular valves and
semilunar valves
 The tricuspid valve regulates blood
flow between the right atrium and
right ventricle.
 The pulmonary valve controls blood
flow from the right ventricle into the
pulmonary arteries
 The mitral valve/bicuspid lets oxygen-
rich blood from your lungs pass from
the left atrium into the left ventricle.
 The aortic valve lets oxygen-rich
blood pass from the left ventricle into
the aorta, then to the body
Blood circulation via
heart
• The blood returns from the systemic circulation to
the right atrium and from there goes through the
tricuspid valve to the right ventricle.
• It is ejected from the right ventricle through the
pulmonary valve to the lungs. (pulmonary circulation)
• Oxygenated blood returns from the lungs through the
pulmonary veins to the left atrium, and from there
through the mitral valve to the left ventricle.
• Finally blood is pumped through the aortic valve to the
aorta and the systemic circulation..
The heart
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Path of Blood Flow-seatwork
Place the following items in the correct sequence: body tissue, aorta, bicuspid valve, left atrium,
lungs, pulmonary trunk, pulmonary arteries, left ventricle, pulmonary veins, right atrium, right
ventricle, tricuspid valve, aortic valve, pulmonary valve.
Oxygen poor blood is collected from the inferior and ___________
_______ ________. It is released into the _________ _______ where it
moves through the _________ valve into the ________ __________.
When the right ventricle contracts, blood is forced through the _________
valve into the ____________ _______ which splits into the left & right
pulmonary __________. Blood is taken via the arteries to the _____
where oxygen & carbon dioxide diffuse through the simple squamous tissue.
Oxygen-rich blood then returns to the heart via the ___________
________ which empty into the _________ ________. Once the atrium
contracts, the blood passes through the __________ ________ into the
_________ _________. Once the ventricle contracts blood is forced
through the _________ valve and out of the _________ to travel to the
_______ ________ .
The Heartbeat/The
Cardiac cycle
 Systole (atrial systole/ ventricular systole)
 Diastole (atrial diastole/ventricular diastole)
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The Conduction System
 Electrical signal begins in
the sinoatrial (SA) node:
"natural pacemaker."
 causes the atria to
contract.
 The signal then passes
through the
atrioventricular (AV)
node.
 sends the signal to the
ventricles via the
“bundle of His”
 causes the ventricles to
contract.
The Conduction System
The normal electrocardiogram
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What is the role of the
brain in controlling the
heart rate
 Increase body activity
 Increase demand for oxygen
 Increase rate of getting rid of CO2
 Increase CO2 in the bloodstream is monitored
by the medulla
 Medulla sends a signal through the cranial nerve
to the SA node to increase the heart rate
 Vagus nerve from the brain does the opposite