Cardiovascular Flashcards
___ in the cardiac myocyte transfer force between cells
desmosomes
____ _____ in the cardiac myocyte transfer current via calcium between cells
gap junctions
what ion is transferred between gap junctions?
calcium
cardiac cells are ____ than skeletal cells
smaller
how many nucleus are in a cardiac myocyte?
1
the ____ is the cardiac contractile unit
sarcomere
what two zones on the sarcomere disappear during contraction?
H zone, I band
where is calcium stored in the sarcomere?
sarcoplasmic reticulum
what act occurring in the sarcomere causes contraction?
calcium binds to troponin
what filament is the outer layer of the sarcomere?
actin/thin
what filament is the inner layer of the sarcomere?
myosin/thick
there are ____ mitochondria in cardiac cells than skeletal cells
more
mitochondria are ____ in cardiac cells than skeletal cells
larger (in volume)
calcium enters the sarcolema through what?
dihydrogen pyrimidine receptor
where in the cell does excitation-contraction coupling take place?
sarcolema (plasma membrane of the cardiac cell)
how do the stores of calcium leave the sarcoplasmic reticulum?
through the ryanadine receptor
where is the DHPR located in the sarcolema?
T-tubule
what triggers the release of calcium from the stores in the SR?
calcium entering the cell through DHRP
describe calcium induced calcium release
calcium entering the sarcolema through DHRP triggers calcium to be released from the SR through the RYR
what does calcium bind to once it is in the sarcolema?
troponin on the sarcomere
what is the name for contraction of the sarcomere?
systole
what is the name for relaxation of the sarcomere?
diastole
what causes diastole of the sarcomere?
calcium releasing from troponin
how does calcium re-enter the SR during diastole/relaxation?
Ca ATP-ase pump