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83 Cards in this Set
- Front
- Back
Four chambered dual action pump.
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The heart
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Circulatory System
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Pulmonary system.
Systemic System. |
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Blood goes to and from the lungs.
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pulmonory system
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Blood goes to and from the rest of the body organs and organ systems.
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systemic system
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Size of an adult heart:
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200-300 grams
Cone shaped About 14cm long and 9am wide. About the size of an adult fist. |
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Location of the human heart:
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Mediastinum, behind the sternum, boarded by the lungs.
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The heart is enclosed by the...
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Pericardium.
The heart is there to make the heart slippery to protect the heart. 3 layers of membranes surrounding the heart. |
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The outer most layer is a...
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dense fibrous connective tissue layer.
Anchors heart inside of the thoracic cavity. |
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Innermost layer is called...
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Visceral Pericardium.
Also called the Epicardium. Epicardium is considered to be the outer most layer of the heart wall. |
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Middle layer is called...
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Parietal Pericardium, a layer that is created when the visceral pericardium folds back on itself at the base of the heart.
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Pericardial Cavity:
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Space between Visceral and Parietal Pericardium.
Filled with a small amount of fluid that allows the layers to slide smoothly past each other when the heart beats. |
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Pericardial Sac:
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Parietal Pericardium and outer layer.
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The heart wall has:
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three layers.
Epicardium, myocardium, endocardium. |
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Epicardium:
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helps reduce friction during cardiac cycle.
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Myocardium:
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Thick middle layer of mostly cardiac muscle contractile tissue.
Cardiac muscle cells: all connected via intercalated Disks. |
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Intercalated Disks
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equivalent of an anchor point, connections between z-lines in adjacent sarcomeres, allows heart cells to contract as a unit "functional syncytium.
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Endocardium:
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Inner most layer of connective tissue, some specialized conducting tissue, and is continuous with the inner linings of blood vessels attached to the heart.
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Four hollow chambers:
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2 left, 2 right, 2 upper, 2 lower.
Septum separates right from left. |
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Upper chambers
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atria (atrium is one chamber)
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Lower chambers
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ventricles
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Left side
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systemic side.
Pumps to systems of the body. |
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Right side
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pulmonary side.
Pumps to the lungs. |
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Receive blood and deliver to ventricles:
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Atria.
Right from the body for eventual delivery back to the lungs. Left from the lungs for eventual delivery back to the body. |
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Receive blood from atria and pump it to the lungs(right) or the body(left).
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ventricles
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Left side of the heart...
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high pressure system.
This side is measured during BP measuring. |
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Right side of the heart...
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low pressure system.
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Diastolic
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The diastolic pressure is specifically the minimum arterial pressure during relaxation and dilatation of the ventricles of the heart when the ventricles fill with blood.
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Systolic
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The blood pressure when the heart is contracting. It is specifically the maximum arterial pressure during contraction of the left ventricle of the heart. The time at which ventricular contraction occurs is called systole.
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Valves of the heart:
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Between the right atrium and ventricle is the TRICUSPID valve.
Between the left atrium and ventricle is the BICUSPID valve (aka MITRAL valve). |
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More heart valves:
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Between the right ventricle and pulmonary trunk is the PULMONARY SEMI-LUNAR valve.
Between the left ventricle and the aorta is the AORTIC SEMI-LUNAR valve. |
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Blood supply:
Coronary Arteries |
Deliver oxygenated blood to the heart cells.
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Blood supply:
Coronary Veins |
Drain deoxygenated blood from the heart cells.
Combine to form a Coronary Sinus: empties blood back into the right atrium. |
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Blood Vessels:
Arteries |
Always carry blood away from the heart.
Divide into arterioles. Made up of smooth muscle tissue (vasomotor fibers), can allow the vessel to contract "vasoconstriction" or relax "vasodilation". This can dramatically influence blood pressure and blood flow distribution. |
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Blood Vessels:
Veins |
Always carry blood to the heart.
Formed from smaller venules. Have NO smooth muscle tissue. Rely on a series of valves and muscular contractions to "pump" blood back to the heart. |
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Blood Vessels:
Capillaries |
Connect the smallest arterioles with the smallest venules.
At some point will allow only one red blood cell to pass at a time. Exchange Zone for O2/CO2 and nutrients and waste products. |
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Right Atrium
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Through the Tricuspid Valve into the right ventricle.
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Right Ventricle
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Through the pulmonary semi-lunar valve into the pumlmonary trunk.
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Pulmonary Trunk
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Into the pulmonary arteries.
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From the pulmonary arteries into the...
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lungs.
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In the lungs...
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arterioles then capillaries then venules.
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Left Atrium...
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through mitral valve.
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Left ventricle...
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through the aortic semi-lunar valve.
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Aorta (aortic arch)...
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divides into branches that feed the body, head and heart.
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Arteries...
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arterioles to capillaries to venules to veins to sup and inf vena cava "Great Vein"
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Ascending Aorta
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Branches into the right and left coronary arteries.
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Aortic Arch
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Brachiocephalic - right arm and right side of head.
Left Common Carotid - left side of head. Left Subclavian - left arm. |
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Descending Aorta
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Brochial artery - bronchi (tubes of the lungs)
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Thoracic Aorta
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Many branches - feed structures in the thoracic cavity
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Abdominal Aorta
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many, many branches - almost all organs, intestines, lower axial skeleton, and lower limbs.
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Cardic cycle
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4 part cycle:
sytole = standing together diastole = standing apart |
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Atrial Systole (the high pressure)
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atrium contracting
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Atrial Diastole (the lower pressure)
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atrium relaxing
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Ventricular Systole
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ventricles contract
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Ventricular Diastole
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ventricles relax
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Electrical events linked to mechaniccal events
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Electrical events made possible via a specialized conducting system in the heart.
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Specialized conducting system:
Pace Maker Cells... |
combined with internal conduction pathways.
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PM cells:
Sinoatrial node |
S-A node initiates the heart rate.
Located at the base of the right atrium. Auto Rhythmic: can initiate its own action potential. |
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Action Potential
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electrical impulse
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Atrial Syncytium
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Cardiac cells linked together by intercalated disks in the atrium.
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Junctional Fibers
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Fibers that conduct the action potential to the ventricles.
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Atrioventricular Node
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A-V Node provides the only link form the SA Node to the ventricles.
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AV Bundle (Bundle of His)
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A large, short pathway that conducts the action potential down into the ventricles.
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Bundle Branches
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Conduct the action potential down the interventricular septum.
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Purkinje Fibers
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Spread the action potential to the cells of the ventricles.
Apex first |
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The action potential itself can be recorded by...
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an electrocardiogram (ECG).
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Electrocardiogram
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recording of electrical events.
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P-wave
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atrial syncytium contraction
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QRS complex
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venticular contraction.
Hides the atrial relaxation. |
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T-wave
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ventricular relaxation.
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Excitabilty
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The basic property that allows a muscle cell to respond to either nervous or hormonal stimulation to create a mechanical contraction.
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Excitation
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contraction coupling.
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Automaticity
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The ability of a cell to initiate its own excitability (create its own action potential).
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Refractoriness
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The inability of a cell to be stimulated to produce another contraction.
ABSOLUTE and RELATIVE refractory periods of the action potential. |
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Conductivity
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The ability to propogate the action potential to adjoining cell.
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SA Node normally...
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regulates heart rate.
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SA and AV nodal cells are under the control of the...
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autonomic nervous system (2 branches).
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Sympathetic
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secrete the hormone norepinephrine which speeds up the SA node which increases heart rate.
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Parasympathetic
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Secretes acetylcholine which slows down the SA node which decreases heart rate.
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Sympathetic and Parasympathetic...
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Work together to regulate heart rate.
Like driving with the gas and the break pressed in your car. |
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Other things can influence heart rate:
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Temperature - as temp increases so will heart rate.
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coronary sinus
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a collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart. It is present in humans and other animals.
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superior and inferior vena cava
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They are the veins that return deoxygenated blood from the body into the heart. They both empty into the right atrium.
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Does the heart have it's own blood supply?
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The muscles of the heart need blood just like any other muscles in the body.
The capillary beds in the walls of the heart are supplied by the Coronary Vessels. The coronary arteries arise from the base of the aorta as it exits the heart and fan out under the visceral pericardium (the outer skin of the heart), sending smaller arterioles into the muscle to supply oxygenated blood to the capillaries. |