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What percentage of the heart lies left of the midline of the sternum?
What is the tough fibrerous sac around the heart?
What is the heart muscle called?
What is Anastomosis?
Communication between 2 or more vessels
what does anastomosis allow?
Collateral circulation- providing an alternative path for blood flow in case of a blockage- telephone ( person to person)
is which part of the heart does the flow process begin?
From the RA to the RV what valve has to open?
What valve is between the LA and LV
Where does the RA pump the blood into?
From the RV where does the blood flow go?
From the Pul Art which chamber of the heart does the blood flow into?
What Vein does blood go through to get to the LA?
Pulm vein - carries o2
What chamber of the heart pumps into the aorta?
What are the 2 antrioventricular valves? av valves?
Tricuspid - right side mitral(bicuspid) left side
what are the 2 semilunar valves?
aortic and pulmonary
preload is after which phase?
what is SOAP?
systole open aortic and pulmonic
in which phase does the tricuspant and mitral valve open?
in which phase are the aortic and pulmonic valve open?
the time from one contraction to the next
during what phase is the myocardium contracting?
during which phase is the myocardium relaxing?
which phase does the cardic chamber fill?
what is preload?
the pressure in the ventricales at the end of diastole
what is afterload?
the resistance against which the heart must pump
what is the frank starling mech?
the more the heart stretches the more forful the contraction
what is cardia output?
stroke volume plus pulse
what is bp?
cardiac output plus vasomotor tone
what is the vasomotor tone?
the sqeezing of the vessels
how does dopamine work?
my contracting blood vessels to raise the vasomotor tone
what is ej fraction?
the ratio of blood pumped out by the ventricales.
what is a normal ej fraction?
what ej fraction do chf patients have?
40 or under
what ej fraction does a pace maker get placed?
20 or below
what is the average stroke volume?
70 ml 2/3 of the blood
what is the flow of blood in the peripheral circulation system?
What kind of cells is blood flow regulated by?
smooth muscle cells ( precapillary sphincters)
what is the main funcation of capillary network?
nutrient and product waste exchange
what is cell death called?
what is sub-endocardial damage?
cell injury to the inside of the heart muscle
what is transmural damage?
full thickness injury to the heart
psns slows down your heart rate?
sns gives off which hormones to raise bp?
epi and norepi
does the psns control the entire heart?
no- only the atria- sa node adn av node
what is chronotropy?
a receptor what controls the heart rate
what is inotropy?
a receptor that controls teh contractile force of the heart
what is dromotropy?
a receptor that controls the speed of the electrical conduction
what is contractility?
ability for the heart to contract
what is excitability?
ability to respond to stimulation
what is conduction?
ability to conduct impulses
what is automaticity?
ability to depolarize itself
does the heart repolorize during contraction or after?
what kind of cells are within the heart?
worker cell and pacemaker cells
how do worker cells work?
cell rests at 90 mv - ports open and sodiem and potassium rush in - this sparks the cells and they go off
how do pacemaker cells work?
patassium leaks out until the cell his -50mv and then fires
What are the electolytes that have a role in the heart cell function?
Calcium- depolorization adn contraction
Potassium- influences repolarization
masnesium- effects cell membrane
what is the most preventant cation outside the cell?
what is the most prevenlant cation inside the cell?
how many times a min do SA node usually fire?
how mant times a min do av junction pacemaker cells fire?
how many times a min do purkinji fibers usually fire?
what is aberrant conduction?
cell to cell conduction
what discs are between the muscle cells that help speed up impulses through the myocardium?
What is a syncytium?
areas of the heart that start the firing of the cells.....all of nothing
what is a premature beat?
fired earlier then expected
what is an escape beat?
fired later than expected - sa node didnt go off so av junction or purkinji fiber took over
what is ectopic beats?
fired from a different area than normal
what is a blocked beat?
delayed of blocked impulses
what is bradycardia?
slower then 60
what is tachcardia?
fast then 100
what is accelerated?
faster than it should be but not quite 100
Cardiac part 1