Vocab #7 Flashcards
AV node
specialized cardiocytes that relay the contractile stimulus from the SA node to the bundle of His, the bundle branches, and Purkinje fibers, and the ventricular myocardium
located at the boundary between the atria and ventricles
cardiac output
the rate of blood ejected by the left ventricle
usually about 5 liters/min.
coronary arteries
two arteries that branch from the aorta that supply the heart with blood
depolarization
a change in the transmembrane potential from a negative value toward 0 mV
diastle
relaxation of the left ventricle
used to measure the diastolic pressure when taking a BP
endocardium
innermost layer of the heart
comprised mostly of epithelial cells to create a smooth lining inside the chambers of the heart and created an ionic barrier between blood and cardiac tissue
erythropoietin
a hormone released by most tissues - especially the kidneys - when exposed to low oxygen concentrations
stimulates red blood cell formation in red bone marrow
mitral valve
the left atrioventricular (AV) valve
regulates blood flow between the left atrium and left ventricle
myocaridum
the cardiac muscle layer of the heart
contains short, branched, single-nucleated cells
between the endocaridum and epicaridum
myocardium
the cardiac muscle layer of the heart
contains short, branched, single-nucleated cells
between the endocardium and epicardium
palpitations
heart rhythm irregularities
most often they are not serious but they can be due to an abnormal heart rhythm
pericardium
the fibrous sac that surround the heart
surround, lubricates, and protects the heart and root of the great blood vessels
composed of the parietal pericaridum and visceral pericaridum
pulmonary circuit
blood vessels between the pulmonary semilumar valve of the right ventricle and the entrance to the left atrium
the blood flow through the lungs
pulmonary valve
allows blood to flow from the right ventricle into the pulmonary artery (then to the lungs for reoxygenation)
a SL valve
prukinje fibers
specialized conducting cardiocytes in the ventricles of the heart
receive signal to depolarize and stimulate both ventricles to contract
repolarization
the movement of the transmembrane potential away from a positive value and toward the resting potential
S1
first heart sound
results from the closure of the mitral and tricuspid valves
lower frequency sound than S2
occurs at the beginning of ventricular systole
S2
results from the closure of the aortic and pulmonic valves
sharper, sounder sound than S1
occurs at end of ventricular systole
S3
results from the impact of inflowing blood against a distended or incompliant ventricle in mid diastole
low-frequency sound occurring about 1/10 of a second after S2