PhysioEx Exercise 6 (continue on
activity 3)
The cardiac muscle is capable of which of the following? - ANSautorhythmicity
Phase 2 of the cardiac action potential,, when the calcium channels remain open and potassium
channels are closed, is called the - ANSplateau phase
Which of the following is true of the cardiac action potential? - ANSthe cardiac action potential is
longer than the skeletal muscle action potential
The main anatomical difference between the frog heart and the human heart is that the frog
heart has - ANSa single, fused ventricle
The amplitude of the ventricular systole did not chance with the more frequent stimulation
because - ANSa new contraction could not begin until the relaxation phase
Which of the following do you think contribute to the inability of cardiac muscle to be tetanized? -
ANSthe long refractory period of the cardiac action potential
Given the function of the heart, why is it important that the cardiac muscle cannot reach
tetanus? - ANSthe ventricles must contract and relax fully with each beat to pump blood
An extrasystole corresponds to - ANSan extra ventricular contraction
The effect of the parasympathetic nervous system on the heart is to - ANSdecrease the heart
rate
The branch of the autonomic nervous system that dominates during exercise is - ANSthe
sympathetic branch
Parasympathetic stimulation reaches the heart through - ANSvagus nerves, which are cranial
nerves
The usual pacemaker of the heart - ANSis the sinoatrial node
Extreme vagus nerve stimulation affects the heart by - ANSstopping the heart completely
Research shows that, in the absence of neural and hormonal influences, the SA node generates
action potentials at a frequency of approximately 100 times per minute. However, the resting
activity 3)
The cardiac muscle is capable of which of the following? - ANSautorhythmicity
Phase 2 of the cardiac action potential,, when the calcium channels remain open and potassium
channels are closed, is called the - ANSplateau phase
Which of the following is true of the cardiac action potential? - ANSthe cardiac action potential is
longer than the skeletal muscle action potential
The main anatomical difference between the frog heart and the human heart is that the frog
heart has - ANSa single, fused ventricle
The amplitude of the ventricular systole did not chance with the more frequent stimulation
because - ANSa new contraction could not begin until the relaxation phase
Which of the following do you think contribute to the inability of cardiac muscle to be tetanized? -
ANSthe long refractory period of the cardiac action potential
Given the function of the heart, why is it important that the cardiac muscle cannot reach
tetanus? - ANSthe ventricles must contract and relax fully with each beat to pump blood
An extrasystole corresponds to - ANSan extra ventricular contraction
The effect of the parasympathetic nervous system on the heart is to - ANSdecrease the heart
rate
The branch of the autonomic nervous system that dominates during exercise is - ANSthe
sympathetic branch
Parasympathetic stimulation reaches the heart through - ANSvagus nerves, which are cranial
nerves
The usual pacemaker of the heart - ANSis the sinoatrial node
Extreme vagus nerve stimulation affects the heart by - ANSstopping the heart completely
Research shows that, in the absence of neural and hormonal influences, the SA node generates
action potentials at a frequency of approximately 100 times per minute. However, the resting
