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Name the layers of the heart!
(Start with outter most layer)
- Pericardium *itself has 2 layers, w. Cavity in between
What is the function of the pericardium?
Anchors the heart in place
Blood flows through the heart via what chambers/parts?
(Start w. Vena cavas n go until lungs)
- Superior & inferior vena cava
- Right atrium
- Tricuspid valve
- Right ventricle (PO2 is 40, PCO2 is 45)
- Pulmonary valve (O2 40, CO2 45)
- Pulmonary artery
Cont. With blood flow direction (start w. Lungs and work back)
- From lungs it enters back into heart via...
- Pulmonary veins (PO2 100, CO2 40)
- Left atrium
- Bicuspid (mitral)
- Left ventricle
- Aortic valve
- Into body--- circulation
What is the chordae tendineae? Function?
Strings on the trip and bi cuspid valves. They prevent them from turning around or flipping
List the coronary arteries!
- Right coronary artery
- --R marginal artery
- --post descending branches
- Left coronary artery
- --anterior descending
List 4 main properties/facts of the heart
- ENTIRELY Aerobic! (can't work without oxygen)
- Automatic (can depolarize itself)
- Interconnected (every cell is "holding hands")
- NO tetanus (no lockup)
tetanus- maximum contraction from rapid firing
Which node is the fastest in the whole heart?
sinoatrial (SA) node, aka the pacemaker! It starts the fire!
Which direction does the SA's signal go?
(towards R or L ventricle or left atrium)
AND where does it go next?
SA signal spreads across the top half of heart (atrium). It won't spread down to ventricles b/c of fibrous skeleton (an electrical insulator).
Signal then reaches atrioventricular node (AV node)
After AV node, what happens next?
1/10th of a second delay then spreads down the AV bundle (AKA the Bundle of Hiss)
after bundle of hiss?
passes to purkinje fibers (located in side walls of ventricles) which pushes up from bottom
What is the only way for signal to travel from atrium to ventricles?
Bundle of Hiss!!
SO in general how does conduction works?
- 1. top contracts first
- 2. bottom pushes up
What is diastole?
What is systole?
what is end diastolic volume?
120ml in the right ventricle (before it's pushed thu pulmonary valve)
what is stroke volume?
80ml, it's vol of blood that gets pushed from R ventricle thru pulmonary valve
what is end systolic?
40ml, it's vol of blood that is left over in R ventricle, doesn't get pumped out
what is ejection fraction?
The % that gets pushed out
In terms of pressure, how does blood move through the heart?
Flows from greater to a lesser pressure
S1 is the sound of which valve closing?
S2 is the sound of which valve closing?
- The time between sounds is systole (contraction)
- The time after 2nd sound, but before 1st is diastole (rest)
Cardiac cycle is the same on both sides, EXCEPT which side has higher pressures?
LEFT side. VOLUME IS THE SAME
Can all the valves be open at same time?
NEVER! but they can be CLOSED at the same time
What is PRELOAD?
End diastolic volume pressure that stretches the right or left ventricle of the heart to its greatest dimensions
What is AFTERLOAD
- It is the stress developed in the wall of the left ventricle during ejection.
- In other words, it is the end load against which the heart contracts to eject blood
What is contractility?
represents the intrinsic ability of the heart/myocardium (muscle) to contract
What does starling law state?
You can only pump what heart gets!
- CO- cardiac output
- VR- venous return
What is the "normal" adult cardiac output
5 liters per min
What controls veinous return? (VR)
- how much blood (volume) &
- how much space to fill