AP 2 EXAM 2 UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

AP 2 EXAM 2 UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

Functional Properties of Cardiac Muscle -Means of Stimulation
-Motor Unit Contraction
-Long Refractory Period
-Numerous Mitochondria


Cardiac Muscle: Means of Stimulation Cardiac muscle cells are self-excitable (automatic or autorhythmic)

, Cardiac Muscle: Motor Unit Contraction The heart contracts as a unit or not at all


Cardiac Muscle: Long Refractory Period Prevents tetanic contractions


Cardiac Muscle: Numerous Mitochondria Relies on aerobic respiration


Sequence of Electrical Events in Contractile Cardiac Influx of Na+ by opening of voltage-regulated fast sodium channels give rise of
Cells: ONE action potential




Sequence of Electrical Events in Contractile Cardiac Transmission of depolarization wave down T tubules releases Ca2+
Cells: TWO




Sequence of Electrical Events in Contractile Cardiac Excitation coupled to contraction, Ca2+ provides a signal
Cells: THREE




Sequence of Electrical Events in Contractile Cardiac Calcium surge across membrane and decreased K+ permeability prolongs
Cells: FOUR depolarization potential, producing plateau in action potential, prolonged
contraction




Intrinsic Conduction System Cardiac muscle (non-contractile) has intrinsic ability to depolarize/contract


Autorhythmic Cells -Unstable resting potential
-Continuously depolarize
-Initiate action potentials that spread throughout the heart


Intrinsic Conduction System of the Heart 1. SA node
2. AV Node
3. AV bundle
4. Bundle branches
5. Purkinje fibers




Cardiac Conduction System -Coordinates and synchronizes heart activity
-Forces heart to contract in units