+
Related Flashcards
Related Topics
Cards In This Set
| Front | Back |
|
In a cardiac muscle contraction _________ of the heart is rhythmic and spontaneous
|
Depolarization
|
|
What do gap junctions do?
|
Ensure the heart contracts as a unit
|
|
In cardiac muscle contraction depolarization opens what?
|
Voltage gated Na+ channels in the sarcolemma
|
|
Reversal of membrane potential goes from what to what?
|
-90mv to +30 mv
|
|
Depolarization wave in T tubules causes the SR to what?
|
Release Ca2+
|
|
In cardiac muscle contraction depolarization wave does what?
|
Opens slow Ca2 channels in the sarcolemma
|
|
In cardiac muscle contraction Ca2+ surge does what?
|
Prolongs depolarization phase (plateau)
|
|
Depolarization is due to what?
|
Na+ influx through fast voltage gated Na+ channels.
|
|
In depolarization a positive feedback cycle rapidly opens many Na+ channels doing what?
|
Reversing the membrane potential. channel inactivation ends this phase
|
|
The plateau phase is due to what?
|
Ca2+ influx through slow Ca2+
|
|
In the plateau phase the Ca2+ influx through slow Ca2+ channels does what?
|
Keeps the cell depolarized because few K+ channels are open for overflow
|
|
Repolarization is due to what?
|
Inactivation of Ca2+ channels and opening of K+ channels.
|
|
In repolarization Inactivation of Ca+ channels and opening of K+ channels allows what?
|
Allows K+ efflux, which brings the membrane potential back to its resting voltage
|
|
Ca2 influx triggers what?
|
Opening of Ca2+ sensitive channels in the SR, which opens up bursts of Ca2+
|
|
Excitation- contracting coupling occurs as Ca2+ binds to tropinin which allows what?
|
Actin and myosin filaments to begin sliding past one another
|
