Cardiac Action potential, MC multiple answer

Group 1

• Phase 0 - Rapid depolarization

• Phase 1 - Initial repolarization

• Phase 2 - Plateau

• Phase 3 - Rapid repolarization

• Phase 4 - Resting membrane potential

• Phase 5 - Hyperpolarization

• Sodium (Na+)

• Potassium (K+)

• Calcium (Ca2+)

• Chloride (Cl-)

• Magnesium (Mg2+)

• Rapid influx of Na+ ions

• Efflux of K+ ions

• Influx of Ca2+ ions

• Efflux of Cl- ions

• Closure of Na+ channels

• Phase 0

• Phase 1

• Phase 2

• Phase 3

• Phase 4

• It involves the influx of Ca2+ ions

• It involves the efflux of K+ ions

• It is characterized by a plateau in membrane potential

• It is the phase of rapid depolarization

• It is the phase of rapid repolarization

• Voltage-gated Na+ channels

• Voltage-gated K+ channels

• Voltage-gated Ca2+ channels

• Ligand-gated Cl- channels

• Voltage-gated Mg2+ channels

• Efflux of K+ ions

• Influx of Na+ ions

• Influx of Ca2+ ions

• Closure of Ca2+ channels

• Opening of Na+ channels

• Phase 0

• Phase 1

• Phase 2

• Phase 3

• Phase 4

• Phase 0

• Phase 1

• Phase 2

• Phase 3

• Phase 4

• It prevents tetanus in cardiac muscle

• It allows time for the heart to refill with blood

• It occurs during the plateau phase

• It is shorter than in skeletal muscle

• It is when the heart muscle is most excitable

• Maintains the resting membrane potential

• Restores ion gradients after action potentials

• Directly causes depolarization

• Directly causes repolarization

• Increases intracellular Ca2+ concentration

• Phase 0

• Phase 1

• Phase 2

• Phase 3

• Phase 4

• It is longer than the action potential in skeletal muscle

• It is shorter than the action potential in neurons

• It involves a plateau phase not present in neurons

• It is initiated by the autonomic nervous system

• It is responsible for the contraction of cardiac muscle

• Prevents premature contractions

• Allows sustained contraction for effective pumping

• Increases the speed of conduction

• Decreases the duration of the action potential

• Facilitates rapid depolarization

• Efflux of K+ ions

• Influx of Na+ ions

• Influx of Ca2+ ions

• Efflux of Cl- ions

• Efflux of Na+ ions

• Na+ influx causes depolarization

• Ca2+ influx maintains the plateau phase

• K+ efflux causes repolarization

• Cl- influx causes depolarization

• Mg2+ influx maintains the plateau phase

• To prolong the refractory period

• To allow time for ventricular filling

• To prevent arrhythmias

• To ensure coordinated contraction

• To increase heart rate

• Closure of Ca2+ channels

• Opening of K+ channels

• Closure of Na+ channels

• Opening of Na+ channels

• Closure of K+ channels

• Na+ current is responsible for the upstroke

• Ca2+ current maintains the plateau

• K+ current is responsible for repolarization

• Cl- current is responsible for depolarization

• Mg2+ current is responsible for the plateau

• Phase 0

• Phase 1

• Phase 2

• Phase 3

• Phase 4

• It is longer than the action potential in skeletal muscle

• It is shorter than the action potential in neurons

• It involves a plateau phase not present in neurons

• It is initiated by the autonomic nervous system

• It is responsible for the contraction of cardiac muscle

• Voltage-gated Ca2+ channels

• Voltage-gated Na+ channels

• Voltage-gated K+ channels

• Ligand-gated Cl- channels

• Voltage-gated Mg2+ channels

• Maintains the resting membrane potential

• Restores ion gradients after action potentials

• Directly causes depolarization

• Directly causes repolarization

• Increases intracellular Ca2+ concentration

• Na+ influx causes depolarization

• Ca2+ influx maintains the plateau phase

• K+ efflux causes repolarization

• Cl- influx causes depolarization

• Mg2+ influx maintains the plateau phase

• To prolong the refractory period

• To allow time for ventricular filling

• To prevent arrhythmias

• To ensure coordinated contraction

• To increase heart rate

• Closure of Ca2+ channels

• Opening of K+ channels

• Closure of Na+ channels

• Opening of Na+ channels

• Closure of K+ channels