Activity 4.3.1
The Heart of
the Matter
Essential Question 1
 What
types of muscles help move
blood around the body?
Cardiac Muscle
Smooth Muscle
Skeletal Muscle
Cardiac Muscle
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Cardiac muscle fibers are shorter in length and larger in
diameter than skeletal muscle fibers.
Cardiac muscle fibers have actin and myosin filaments
arranged in the same way as skeletal muscle, but usually
only one nuclei.
In contrast to skeletal muscle, cardiac muscle does not
fatigue, cannot be repaired when damaged and is
regulated by the autonomic nervous system.
Gap junctions between the fibers allow ions to travel
between cells to permit the rapid fire of action potentials.
Excitement of a single fiber results in stimulation of all the
other fibers in the network (ALL OR NONE) . As a result,
each network contracts as a functional unit.
Cardiac Muscle
Smooth Muscle
Arteries have smooth muscle that functions
to regulate the flow of blood through the
artery.
 Contraction of the smooth muscle decreases
the internal diameter of the vessel in a
process called vasoconstriction.
 Relaxation of the smooth muscle increases
the internal diameter in a process called
vasodilation.
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Smooth Muscle
Where else can you find
Smooth Muscles
Walls of
stomach
Uterus
Intestines
Iris of the eye
GI Tract
Respiratory
Tract
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.
Kidneys
Bladder
Ureters
Ciliary
muscle
Sphincter
Trachea
Bile duct
Skeletal Muscle.
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Veins pass between skeletal
muscles. The contraction of
skeletal muscle squeezes the
vein.
Repeated cycles of
contraction and relaxation of
skeletal muscle, as occurs in
the leg muscles while
walking, helps facility blood
back to the heart.
Skeletal Muscle
What do you remember from PBS
about the heart?”
1_______________
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 3___________
 4___________
 5___________
 6___________
 7___________
 8___________
 9__________
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Position and Shape of the Heart.
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The heart is located in the thoracic cavity in
between the lungs, 60% of it lying to the left of
the median plane.
The heart is cone-shaped, with a broad base at
the top from which the large blood vessels enter
and exit.
The tip, known as the apex, points downwards
and lies close to the sternum.
Pericardium
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A membrane that surrounds and protects the
heart. It is composed of two layers containing a
small volume of fluid which serves as a lubricant,
facilitating the movement of the heart by
minimizing friction.
The inner layer is firmly attached to the heart wall
and is known as the visceral layer or epicardium.
The outer layer is composed of relatively inelastic
connective tissue and is termed the parietal layer.
Layers of the Heart Wall
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The wall of the heart consists of three layers:
 epicardium (external layer), is the thin, transparent outer
layer of the wall and is composed of delicate connective
tissue.
 myocardium (middle layer), comprised of cardiac muscle
tissue, makes up the majority of the cardiac wall and is
responsible for its pumping action. The specific regions
dictates the thickness of the myocardium.
 endocardium (inner layer). is a thin layer of endothelium.
It provides a smooth lining for the chambers of the heart
and covers the valves. It is continuous with the endothelial
lining of the large blood vessels attached to the heart
Fibrous Skeleton
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In addition to cardiac muscle tissue, the heart wall also
contains dense connective tissues that:
 forms the fibrous skeleton of the heart.
 forms rings that surround the four heart orifices.
The skeleton performs several functions:
 It serves as a point of attachment for the heart valves.
 It prevents the valves from overstretching as blood passes
through them.
 It acts as an electrical insulator thereby preventing the
direct spread of action potentials from the atria to the
ventricles.
Chambers of the Heart
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The heart contains four chambers where the thickness
of the myocardium of the chambers varies according
to its function.
The two upper chambers are the atria. The atria are
thin-walled because they deliver blood into the
adjacent ventricles. On the upper surface of each
atrium is a pouch-like appendage which is thought to
increase the capacity of the atrium slightly.
The two lower chambers are the ventricles. The
ventricles are equipped with thick muscular walls
because they pump blood over greater distances.
Ventricles
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The right and left ventricles act as two separate
pumps that simultaneously eject equal volumes
of blood. The right ventricle only pumps blood
into the lungs, which are close by and present
little resistance to blood flow so work load is less.
On the other hand, the left ventricle pumps blood
to the rest of the body, where the resistance to
blood flow is considerably higher. Therefore, the
left ventricle works harder than the right ventricle
to maintain the same blood flow rate.
Consequently, the left ventricle is significantly
thicker than that of the right.
Right Atrium (RA)
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The right atrium forms the section of the base of
the heart and receives blood from the superior vena
cava, inferior vena cava and coronary sinus.
Blood flows from the right atrium to the right
ventricle through the tricuspid valve (also know as
the right atrioventricular valve).
The right atrium also houses the sinoatrial node.
Right Ventricle (RV)
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The right ventricle forms most of the anterior surface
of the heart and is crescent-shaped in cross-section.
The tricuspid valve provides the means for blood to
leave the RA and move into the RV
The right ventricle is separated from the left by a
partition called the interventricular septum.
Deoxygenated blood passes from the right ventricle
through the pulmonary semi-lunar valve to the
pulmonary trunk, which conveys the blood to the
lungs.
Left Atrium (LA)
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The left atrium forms the section of the base of the
heart and is similar to the right atrium in structure
and shape.
It receives oxygenated blood from the lungs via the
pulmonary veins.
Blood passes from the left atrium to the left ventricle
through the bicuspid or mitral valve.
The left atrium lies under the tracheal bifurcation
and enlargement of this area of the heart can cause
breathing difficulties.
Left Ventricle (LV)
The left ventricle forms the apex of the
heart and is conical in shape.
 Blood passes from the left ventricle to the
ascending aorta through the aortic valve.
 From here some of the blood flows into the
coronary arteries, which branch from the
ascending aorta and carry blood to the
heart wall.
 The remainder of the blood travels
throughout the body.
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Coronary vasculature
Conduction system
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Animation: Conducting System of the Heart
Think about blood supply to....
EKG
Electrical Conduction
Essential Question 2 & 3
 What
is the relationship
between the heart and the
lungs?
 What is the pathway of blood
in and out of the heart in
pulmonary and systemic
circulation?
Activity 4.3.2
Varicose
Veins
Varicose Veins
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Normally, one-way valves
in the veins keep blood
flowing from your legs up
toward your heart.
Varicose veins are caused
by weakened valves in the
veins in your legs.
When these valves do not
work as they should, blood
collects in your legs, and
pressure builds up.
Varicose
Veins
As pressure builds in
the veins, the walls
of the veins become
weak, dilated, and
twisted.
 Venous return is
slowed, causing
blood to become
sluggish.
www.sirweb.org/news
/videoClips.shtml

Causes of Varicose Veins
Varicose veins often run in families.
 Aging increases your risk.
 Increased pressure on leg veins from
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Being overweight
 Pregnancy
 Or having a job where you must stand for
long periods of time.
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The structure of blood vessels is in direct
relationship to the function it performs
Artery
Vein
Capillary
Cross section of an artery
 Why
don’t
we get
varicose
arteries.
Essential Question
4. How do the structure of arteries, veins
and capillaries relate to their function in
the body?
5. What unique features of veins help
move blood back to the heart?
6. What are varicose veins?
7. Why don’t we ever hear about varicose
arteries?
View Vessel Slides
Draw in your journal what you saw in the
slides
 With team of 4 devise a way to explain how
varicose veins form and why we done get
varicose arteries.
 Final product could be drawing, diagram,
information brochure, clay model, or a
letter to your grandmother to answer her
questions about varicose veins.
 Present your findings to the class
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Activity 4.3.3
Go With the Flow
The Flow
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Blood vessels move blood from the heart to the lungs to pick
up oxygen and deliver this oxygen to all of the tissues of the
body.
Arteries flow away from the heart and branch into smaller
vessels called arterioles.
Arterioles lead into the capillary beds, thin nets of vessels
where gas exchange occurs.
Blood then converges back into small veins called venules
and eventually back into the major veins to be returned to
the heart.
Vessel size varies dramatically along this path.
Make paper Flag for these
vessels
Ascending Aorta
Descending Aorta
Brachiocephalic artery
Subclavian artery/vein
Carotid artery vein
Radial artery/vein
Ulnar artery/vein
Common Iliac Vein
Superficial palmar arch
Renal artery/vein
Iliac artery/vein
Femoral artery/vein
Popliteal artery/vein
Posterior Tibial artery/vein
Superior Vena Cave
Inferior Vena Cava
Internal Jugular vein
Build this on Maniken
One Brachiocephalic Artery
The aorta is the largest artery in the body
about the diameter of a garden hose.
 The capillaries, on the other hand, are so
tiny that about ten of them would be as
thick as one of the hairs on our head.
 The structure of blood vessels relates
directly to their particular function and to
the amount of pressure exerted on the
vessel walls.
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.
Essential Question
8.
What are the major arteries
and veins in the body and
which regions do they serve?
Arteries in the arm
Veins in the Arm
Veins more superficial
Activity 4.3.4
Cardiac Output
Cardiac Output
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Cardiac Output is a measure of how
much blood the heart can pump in one
minute by the ventricles.
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Cardiac Output (ml/min) = Stroke
Volume (75ml/beat) X Heart Rate (BPM)
What are some diseases that affect
CO if dependent on SV & HR
hypertension
 heart failure
 infection and sepsis
 cardiomyopathy
 rhythm disturbances
 coronary artery disease
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Essential Question
9. What is cardiac output?
10. How does cardiac output help assess
overall heart health?
11. How does an increased or decreased
cardiac output impact the body?
Changes in cardiac output
often signal diseases of the heart and
these changes can impact the function of
other body systems.
 Increased blood pressure in vessels can
indicate possible blockages, and these
blockages can interrupt blood flow to an
organ or limb
 Increased BP decreases Cardiac Output in
a diseased heart
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Activity 4.3.5
Smoking Can Cost
You an Arm and a
Leg!
Essential Question
12. What is blood pressure?
13. How can the measurement of
blood pressure in the legs be
used to assess circulation?
Blood Pressure
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When your heart beats, the
contraction forces blood through
the arteries to the rest of your
body. This pressure created on the
arteries is called systolic blood
pressure, and measured in (mm
Hg)
A normal systolic blood pressure is
below 120.
The diastolic blood pressure
number or the bottom number
indicates the pressure in the
arteries when the heart rests
between beats.
A normal diastolic blood pressure
number is less than 80.

http://www.sirweb.org/video/Peripheral
_Arterial_Disease_Smoking.mpg
http://www.sirweb.org/video/Peripheral_Arte
rial_Disease_Smoking.mpg
http://www.sirweb.org/news/videoClips.shtml
Complete Part I and share your findings with
class before receiving part II
Part II-Draw a feedback loop to show the
body responds to an increase in BP
 Part III- Take ABI measurements
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Example of BP feedback loop
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In the example to the right
blood pressure has
increased. Receptors in the
carotid arteries detect the
change in blood pressure
and send a message to the
brain. The brain will cause
the heart to beat slower
and thus decrease the
blood pressure. Decreasing
heart rate has a negative
effect on blood pressure.
FYI
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Decreased blood volume or blood pressure stimulates the release of
Renin that starts the process
The glomulerus, a bundle of capillary blood vessels found in the kidney,
senses a drop in blood flow or a drop in sodium and secretes an enzyme
called renin into the bloodstream.
Renin moves to the liver where it converts the inactive peptide
angiotensiongen to angiotensin I.
Angiotensin I travels to the lungs where another enzyme converts it to
angiotensin II.
Angiotensin II makes its way to the adrenal glands at the top of the kidneys
where it stimulates the production of aldosterone.
Aldosterone helps the kidneys conserve sodium and water, leading to
increased fluid volume and sodium levels.
NOTE: If blood flow to the kidneys or the amount of sodium increases, less
renin is produced in an attempt to normalize blood pressure.
Animation:
http://www.people.vcu.edu/~elmiles/hormones/KidneyHormones
3.html
Ankle Brachial Index (ABI)
A test done by measuring blood pressure
at the ankle and in the arm while a person
is at rest.
 Measurements are usually repeated at
both sites after 5 minutes of walking on a
treadmill.
 A slight drop in the ABI with exercise,
even if you have a normal ABI at rest,
means that you probably have PAD.

Part IV Activity 4.3.5
Doppler ultrasound device
 Activity 4.3.5 Student Resource Sheet
– ABI Worksheet.
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Project 4.4.1
The Body’s
Response to
Exercise
Essential Question
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1. What is the connection between
power and movement in the body?
 ATP
Recall how the body generates ATP.
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Food (primarily glucose) and oxygen are both vital to
the assembly of ATP
ATP is always stored in the body but the amount in the body can only last 2 or 3
seconds. When it is used it is broken down from one adenozine and three
phosphate molecules into adenzine diphosphate (2 phosphate molecules) and a
separate phosphate molecule. This reaction is exothermic and produces energy.
There are three main ways it can be resynthesised and these are by using the
phospho-creatine system, the lactic system and the aerobic system.
Aerobic resipration is much more complicated as oxygen is present. It starts the
same way as lactic respiration but as oxygen is present, there is no lactic acid
formed, instead pyruvic acid is converted into acetyle CoA by the enzyme
coenzyme A. The acetyle CoA is then converted into citric acid by oxaloacetic acid.
The citric acid then goes through something called the Krebs cycle where
everything produced in respiration except the energy is removed. This leaves 2 ATP
molecules. The hydrogen removed from the reaction then is converted using
something called an electron transfer chain into 34 ATP molecules and water.
Essential Question
2. How does the body maintain a supply a
ATP during exercise?
 Exercise requires the coordinated effort of
many human body systems including

nervous system,
 muscular system,
 skeletal system,
 cardiovascular system,
 respiratory system.
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Cellular respiration is the process by which ATP
is Produced
ATP is the main energy source used by the cells
 Organic molecules such as glucose, lipids, and
proteins are broken down to produce ATP
 3 stages of cellular respiration, Glycolysis, Krebs
cycle, Electron Transport Chain (ETC)
 http://www.sophia.org/tutorials/biology-amanda-3atp-production-video-overview-det
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A nucleotide used by cells as a form
of energy.
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Cellular Respiration
-Process that occurs in cells to produces ATP for cells in order to carry out all cell functions.
-ATP is produced by the breaking down of organic molecules such as glucose, lipids and proteins
3 Stages of Cellular Respiration
-Glycolysis is the first stage
-Krebs Cycle is the second stage
-Electron Transport Chain is the third stage
ATP
-ATP is a nucleotide with a ribose sugar, adenine base and 3 phosphate groups
-Energy stored between 2nd and 3rd phosphate group
Glycolysis
-1st step of cellular respiration
-Occurs in cytoplasm of the cell
-Glucose is broken down into a smaller molecule
-Products of gylcolysis move into the next step
The Krebs Cycle
-2nd step of cellular respiration
-Occurs in the mitochondria
-The mitochondria is the “powerhouse” of the cell
ETC
-3rd step of cellular respiration
-Occurs in the mitochondria
-1 molecule of glucose yields 36 molecules of ATP
-Most of the ATP is being produced by the ETC
-A minor amount of ATP is produced in glycolysis and the Krebs cycle
Activity 4.4.2
Mind Over Muscle
Problem 4.4.4
Training a
Champion
Essential Questions
What is peripheral artery disease?
 Why can smoking lead to peripheral
artery disease?
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Key Terms
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Aorta -The large arterial trunk that carries blood from the heart to be
distributed by branch arteries through the body.
Arteriole- Any of the small terminal twigs of an artery that ends in
capillaries
Artery- Any of the tubular branching muscular- and elastic-walled vessels
that carry blood from the heart through the body.
Arteriosclerosis-A chronic disease characterized by abnormal thickening
and hardening of the arterial walls with resulting loss of elasticity
Atherosclerosis- A cardiovascular disease in which growths called
plaques develop on the inner walls of the arteries, narrowing their inner
diameters.
Atrium- A chamber of the heart that receives blood from the veins and
forces it into a ventricle or ventricles.
Key Terms
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Blood pressure-The hydrostatic force that blood exerts against the wall
of a vessel.
Capillary-Any of the smallest blood vessels connecting arterioles with
venules and forming networks throughout the body.
Cardiac muscle-Striated muscle fibers (cells) that form the wall of the
heart; stimulated by the intrinsic conduction system and autonomic motor
neurons
Cardiac output -The volume of blood ejected from the left side of the
heart in one minute.
Circulation-The movement of blood through the vessels of the body
that is induced by the pumping action of the heart and serves to
distribute nutrients and oxygen to and remove waste products from all
parts of the body.
Coronary Artery-Either of two arteries that arise one from the left and
one from the right side of the aorta immediately above the semilunar
valves and supply the tissues of the heart itself
Key Terms
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Heart rate- A measure of cardiac activity usually expressed as number of
beats per minute
Peripheral artery disease- A form of peripheral vascular disease in
which there is partial or total blockage of an artery, usually one leading to
a leg or arm.
Peripheral vascular disease- Vascular disease affecting blood vessels
outside of the heart and especially those vessels supplying the extremities.
Pulmonary Circulation- The passage of venous blood from the right
atrium of the heart through the right ventricle and pulmonary arteries to
the lungs where it is oxygenated and its return via the pulmonary veins to
enter the left atrium and participate in the systemic circulation
Pulse - A regularly recurrent wave of distension in arteries that results
from the progress through an artery of blood injected into the arterial
system at each contraction of the ventricles of the heart.
Key terms
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Smooth muscle
A tissue specialized for contraction, composed of smooth muscle fibers
(cells), located in the walls of hollow internal organs, and innervated by
the autonomic motor neurons
Stroke volume
The volume of blood pumped from a ventricle of the heart in one beat
Systemic Circulation
The passage of arterial blood from the left atrium of the heart through the
left ventricle, the systemic arteries, and the capillaries to the organs and
tissues that receive much of its oxygen in exchange for carbon dioxide and
the return of the carbon-dioxide carrying blood via the systemic veins to
enter the right atrium of the heart and to participate in the pulmonary
circulation
Key Terms
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Valve
A bodily structure (as the mitral valve) that closes temporarily a passage or
orifice or permits movement of fluid in one direction only.
Varicose vein
An abnormal swelling of a superficial vein of the legs.
Vein
Any of the tubular branching vessels that carry blood from the capillaries toward
the heart and have thinner walls than the arteries and often valves at intervals to
prevent reflux of the blood which flows in a steady stream and is in most cases
dark-colored due to the presence of reduced hemoglobin.
Ventricle
A chamber of the heart which receives blood from a corresponding atrium and
from which blood is forced into the arteries.
Venule
Any of the minute veins connecting the capillaries with the larger systemic veins