Unit 2 Exam Lab 8 Flashcards
The correct sequence of the wave of depolarization that passes through the heart is:
1 = atrioventricular (AV) node
2 = sinoatrial (SA) node
3 = Purkinje fibers
4 = bundle of His
5 = bundle branches
2,1,4,5,3
A resting membrane potential of -85 mV means that
the inside of the cell is more negative with respect to the outside of the cell.
During membrane depolarization, ______move _____ the cell through _____.
Na+, into, voltage gated channels
During membrane repolarization, _____ move _____ the cell through _____.
K+, out of, voltage gated channels
mass of cells that function as one
functional syncytium
cells capable of spontaneously depolarizing
pacemaker cell
pacemaker cell located in an unexpected site
ectopic pacemakers
baseline for ECG
isoelectric line
anatomical structure responsible for spread of wave of depolarization from cell to cell in cardiac tissue
intercalated dics
anatomical structure that prevents the spreading of action potentials directly from atrial myocardium to the ventricular myocardium
exoskeleton, fibrotendonous rings
which type of cardiac cells demonstrate slow response action potentials
SA node, AV node, ecotopic pacemaker cells
which type of cardiac cells demonstrate fast response action potentials
bundle of his, bundle of branches, purkinje fibers, atrial muscle cells, ventricular muscle cells
Which of the following can serve as pacemaker cells in the heart?
SA node, AV node, ecotopic pacemaker cells found in sites other than in the SA and AV nodes
The intracellular concentrations of _____ are greater than the extracellular concentrations in both pacemaker and non-pacemaker cells.
K+
The extracellular concentrations of _____ are greater than the intracellular concentrations in both pacemaker and non-pacemaker cells.
Na+ and Ca2+
Which of the following statements best describe the movement of Na+ across the membrane during the prepotential stage of slow response action potentials.
Na+ diffuses slowly from the outside to the inside through leakage channels.
Which of the following statements best describe the movement of K+ across the membrane during the prepotential stage of slow response action potentials?
K+ has reduced permeability for diffusing from the inside to the outside
Which of the following statements best describe the movement of Ca++ across the membrane during the prepotential stage of slow response action potentials?
Ca++ diffuses slowly from the outside to the inside through leakage channels.
During depolarization phase of slow response action potentials:, Na+:
is not involved in slow response action potential depolarization
During depolarization phase of slow response action potentials:, K+:
is not involved in slow response action potential depolarization
During depolarization phase of slow response action potentials:, Ca++:
diffuses rapidly from the outside to the inside of the cell
During repolarization of slow response action potentials, Na+:
is not involved in slow response action potential repolarization
During repolarization of slow response action potentials, K+:
diffuses rapidly from the inside to the outside of the cell
During repolarization of slow response action potentials, Ca++:
is not involved in slow response action potential repolarization
