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Do Now
Finish the “Heart Disease” article and questions.
Cardiovascular System
Ch.13
Objectives
- Identify the organs of the cardiovascular
system and its overall function.
- Label the different parts of the heart.
The Cardiovascular System
- Pumps 7,000 liters of a blood a DAY!!!
- Contracts about 2.5 billion times in a lifetime
- Functions to carry oxygen and nutrients to the cells
of the body and carry carbon dioxide and other
waste away from the cells of the body.
Structures of the System
1. Heart
- pumps blood to the lungs
and throughout the body
2. Arteries, arterioles
- Carry blood AWAY from the
heart to cells
3. Capillaries
- Tiniest tubes; place where
nutrient and gas waste
exchanges
4. Veins, venules
- Carry blood TO the heart
from cells
Arteries vs. Veins
- Arteries
- Strong, elastic, thick
- Carry blood AWAY
from the heart
under high pressure
- Veins
- Thinner, not as
elastic
- Contain 1-way
valves
Pulmonary vs. Systemic Circuits
- Pulmonary
- Carries Oxygen
depleted blood
(deoxygenated) to the
lungs to pick up O2 and
unload CO2.
- Systemic
- Sends oxygen-rich
(oxygenated) blood
from heart to all body
cells.
The Heart
- Located in the thoracic
cavity within
mediastinum
- Rests on top of the
diaphragm
- Distal end extends to
the left
- Encased in a “parietal
pericardium”
Wall of the Heart
1. Outer Epicardium
(visceral pericardium)
• Serous membrane,
consists of connective
tissue
• Protects the heart by
reducing friction
2. Middle Myocardium
• Thick, mostly cardiac
tissue involved in
pumping blood out of
the heart
3. Inner Endocardium
• Made of epithelial and
connective tissue
• Lines the inner
chambers of the heart
Heart Chambers
- Atria
- Upper chambers
- Receive blood returning
to the heart
- Ventricles
- Lower chambers
- Receive blood from atria
and force blood into
arteries
- Septum
- Separates left and right
so blood doesn’t mix
Septum
*Remember anatomical
position!!
Objectives
- Explain the flow of blood through the heart,
lungs, and body.
- To label a diagram of the heart.
- Compare and contrast angina vs. a heart
attack.
Heart Valves
- Atrioventricular
Valves:
separate atria
from ventricles
and prevent
back-flow of
blood:
- Tricuspid:
- Right side
- Bicuspid/Mitral:
- Left side
Leaky valve
Heart Valves (cont.)
- Semilunar Valves:
- Pulmonary:
- Found between the
right ventricle and the
pulmonary artery
- Aortic:
- Found between the
left ventricle and the
aortic arch
Heart Valve Abnormalities
- Heart “murmur”
1. Regurgitation: valve doesn’t close properly,
blood regurgitates back into atrium
• Mitral valve prolapse: valve contracts and
stretches, bulging into the left atrium
2. Stenosis: not enough blood passes through
Different heart sounds!
Heart Diagram Labeling!
Pathway of Blood
- Great Pathway of Blood Video!
Blood Flow
• Please fill out the pathway of blood through
the heart on your worksheets!
Blood Supply to the Heart
• Coronary arteries:
– first two branches of the
aorta
– supply blood to the
tissues of the heart
• Cardiac veins:
– bring deoxygenated
blood from heart tissue
to coronary sinus
(empties into right
atrium)
Angina Pectoris
- A “thrombus” or “embolus” partially blocks or narrows a coronary
artery and deprives myocardial cells of oxygen, causing pain.
*many people mistake this for a heart attack
- A complete blockage by a blood clot is a myocardial infarction (aka
heart attack)
Do Now
- What part of the heart pumps oxygenated
blood to the body and what “tube” does it go
through?
- Name 2 differences between arteries and
veins.
- What is another name for the visceral
pericardium?
Objectives
- To explain the flow of blood through both
pulmonary and systemic circuits.
- To understand the cardiac cycle.
- To explain what causes your “heart beat”.
Do Now
- What do you think causes your heart beat?
- Write the flow of blood ONLY through the
heart.
Objectives
- To explain what occurs in a normal cardiac
cycle.
- To define systole and diastole.
- To measure ones pulse to determine their
heart rate.
- To determine what causes heart sounds.
Cardiac Cycle
- Systole= contraction
- Diastole = relaxing
* During atrial systole, ventricles are in
ventricular diastole
* During ventricular systole, atria are in atrial
diastole
- Both relax briefly after ventricular systole
- Cycle Animation
Steps of the Cycle
1) Pressure is low during ventricular diastole,
opening the A-V valves (tricuspid/bicuspid)
2) Ventricles fill with blood, atrial systole occurs
3) A-V valves close when ventricular pressure
exceeds atrial pressure
1) Papillary muscles pull on chordae tendinae to
prevent valves from bulging back into atria (which
would cause a murmur)
4) During ventricular systole, atrial pressure is low
and they begin to fill up again
Steps of the Cycle
5) Ventricular pressure rises, opening the
semilunar valves, forcing blood into the
pulmonary trunk and aortic arch (ventricular
systole)
6) Pressure drops in ventricles after contraction,
and the semilunar valves close.
Echocardiogram
Heart Sounds
- The heart makes a “Lubb-Dupp” sound
- The “Lubb” is the closing of the A-V valve
during ventricular contraction.
- The “Dupp” is the closing of the semilunar
valve when the ventricles are relaxing.
Pulse of Life Lab
- You will be measuring your pulse and seeing
how your heart rate is affected by different
activities!
- You will turn in the series of questions upon
completing the lab as well as construct a
graph.
Do Now
- Explain the steps of the cardiac cycle.
- How do you think these steps are
coordinated?
Objectives
- To explain the cardiac conduction system
- To identify the components of an EKG
- To identify different heart arrhythmias
Cardiac Muscle Fibers
• Cardiac muscle fibers form a network called a
functional synctium which contracts as a unit.
Cardiac Conduction System
- Coordinates the events of the cardiac cycle
Cardiac Conduction System
1) The Synoatrial Node (SA Node)- “Pacemaker”
- Specialized cardiac muscle tissue
- Can reach threshold on its own
- Generates impulses 70-80 times per minute
2)
3)
4)
5)
Atrial synctium- causes atrial contraction
A-V Node
A-V Bundle (Bundle of His)
Purkinje Fibers- causes ventricular
contraction
Cardiac Conduction
• Conduction
Electrocardiogram
• Recording of the electrical changes that occur
in the myocardium (cardiac muscle)
Electrocardiogram
• P-wave:
depolarization of
atria
• QRS: depolarization
of ventricle fibers
(R=Left, S=right)
• T-wave:
repolarization of
ventricles
Researching Arrhythmias
•
•
•
•
•
•
V-fib (Ventricular Fibrillation)
Sinus Bradycardia
Sinus Tachycardia
Atrial Fibrillation
Atrial Flutter
Asystole
Do Now
• In your own words,
Explain the cardiac
conduction system
and how it works to
control the cardiac
cycle.
Objectives
• To identify EKG’s of different heart
arrhythmias.
• To determine how fast a heart is beating by
looking at an EKG.
• To explain blood pressure readings and
understand how blood pressure can be
effected.
Reading an EKG
• Read the article about reading an EKG!
• How can you figure out the rate?
Blood Pressure (13.5)
• Blood pressure= the force blood exerts
against the inner walls of blood vessels.
• Interesting Fact! The human heart creates
enough pressure to squirt blood 30 feet!!
Measuring Blood Pressure
• Systolic Pressure:
max pressure during
ventricular systole
• Diastolic Pressure:
max pressure during
ventricular diastole
What gives us a “pulse”?
• Ventricular contraction causes a “surge” in
arteries, distending the elastic arterial walls,
pressure drops immediately after contraction
• Only felt in arteries close to the surface such
as your carotid in your neck.
Factors Affecting Blood Pressure
• Heart Action
– Stroke volume (vol of blood discharged with each
contraction) and heart rate
• Blood Volume
– If you lose a lot of blood, your blood pressure will be
lower.
• Peripheral Resistance
– If the vessels are constricted, pressure increased
• Blood Viscosity
– More viscous=more pressure