A&P Heart

heart is divided into ___ sides
heart is divided into ____ chamber
heart automaticity
the ability to initiate electrical stimulus independently
heart excitability
the ability to respond to electrical stimulation
heart conductivity
transmit electrical stimulation from cell to cell in heart
heart contractility
stretch as a single unit and recoil (heart beat) contraction
heart rhythmicity
repeat cycle with regularity
heart attack
cardiac arrest
heart stops
tissue damage
left side of heart
sends oxygenated blood to the body
right side of heart
receives deoxygenated blood from the body
what divides the heart in two
tissue layers of the heart
endocardium, myocardium, epicardium
lines the inside of the cardiac chamber, made of thin endothelial cells
middle layer, made of muscle fibers and responsible for pumping
made of fibrous & loose connective tissue, also know as visceral pericardium
visceral pericadium
sac that surrounds & protects the heart
2 types of valves
atrioventricular, semilunar
atrioventricular valves
"lub" separates the atria from ventricles
2 types of atrioventricular valves
tricuspid and mitral valve(bicuspid)
tricuspid valve
separates RA & RV
mitral(bicuspid) valve
separates LA & LV
semilunar valves
"dub" separates the ventricles from the aorta and pulmonary artery
2 types of semilunar valves
pulmonary and aortic
pulmonary valve
separates RV & pulmonary artery
aortic valve
separates the LV from the aorta
2 major coronary arteries
branches off to supply the nerve tissue of the conduction system
branches off into the LAD and circumflex artery, supplies blood to LA, LV and septum
SA node
starling's law
greater the stretch of myocardium, the stronger the ventrical contraction(heart beat)
the heart beat begins: electrical impulse initiates the SA node to fire-
SA node sends the stimulus to the AV node through internodal tracts-
AV node will initiate electrical stimulus if SA node malfunctions at a rate of
40-60 bpm, stimulus sent to bundles of his from here-
bundle of his branches off into the lt and rt bundle branches-
feed the ventricles rt and lt and bachmann's bundle down to
purkinje fibers which are end of conduction system,
once stimulation here, the ventricles contract.
normal SA node rate is
60-100 bpm
SA node is
located in the back wall of the RA
AV node is
located right above the atrioventricular septum
bundle of his is
located in the septum
during the electrical conduction, electrical movement of cells is from polarization to
once contraction occurs, the charges inside the cells
returns to normal until the next stimulus is sent. this process is called repolarization
polarization is
negative state inside the myocardial cells, cells at rest
depolarization is
positive state inside myocardial cell