Download Cardiovascular System Notes

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!
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)
Pathway of Blood
- Great
Pathway of
Blood
Video!
Blood Flow
• Please fill out the pathway of blood through
the heart on your worksheets!
Blood Flow Chart
What gives us a pulse?
“Pulse of Life” Lab!
-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
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 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)
1) Ventricles fill with blood, atrial
systole occurs
2) 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
Steps of the Cycle
4) Atrial pressure is low (atrial diastole) and they begin
to fill up again to start next 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.
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 bands of muscle
that wind around the heart
• Work as a unit called a functional syncytium:
–Allows top and bottom parts to contract in their
own unique way
Cardiac Conduction System
- Coordinates the events of the cardiac cycle
Cardiac Conduction System
1)
2)
3)
4)
5)
6)
7)
The Sinoatrial Node (SA
Node)- “Pacemaker”
- Specialized cardiac
muscle tissue
- Can depolarize on its
own
- Generates impulses 7080 times per minute
Atrial syncytium: causes
atrial contraction
A-V Node
A-V Bundle (Bundle of His)
Right and left bundle
branches
Purkinje Fibers
Ventricular syncytium:
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 complex:
depolarization of
ventricular fibers
• T-wave:
repolarization of
ventricles
Researching Arrhythmias
•
•
•
•
•
•
V-fib (Ventricular Fibrillation)
Sinus Bradycardia
Sinus Tachycardia
A-fib (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?
Do Now: Identify the EKG’s!
Normal EKG
A.
B.
C.
D.
E.
Blood Pressure
• 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
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