Cardiac action potential (pacemaker potential) path through heart
11. Describe the generation of pacemaker action potentials and then track the resulting impulse through the cardiac conduction system. Include the names of specific types of channels in the first part of your answer.
Complete the Concept Map to describe ionic movement during
action potentials in cardiac pacemaker and contractile cells, and
trace the conduction pathway.
pacemaker cells K+ ions Ca2+ ions cardiac muscle fibers Na ions SA nodes AV nodes, Reset Help bundles, branches and Purkinje fibers rapidly depolarize due to influx of directly trigger atria to contract and activate enter plateau phase due to slow influx of repolarize due to efflux of directly trigger ventricles to contract and activate directly trigger atria...
Part A The "pacemaker potential of pacemaker cells is produced by the opening of at the end of an action potential. O K+ channels O slow Na+ channels fast Ca2+ channels slow Ca2+ channels Submit Request Answer
Parasympathetic effects on the cardiac pacemaker cells of the SA node include a reduction in Ca++ influx and increased K+ efflux. Explain how these two effects decrease the heart rate
Compare and contrast the molecular events of the action potential in the pacemaker cells of the SA node to those in a ventricular (contractile) cardiomyocyte. Be sure to point out how these molecular events underlie the differences in the shapes of the two types of potentials and how these differences serve the difference in functions for these cell types.
1. A) What is the trigger for initiating an action potential in a cardiac cell? B) What phase or event of an action potential is the trigger for the actual muscle contraction? 2. Why do you believe a defect or blockage in the cardiac conduction system would cause cardiac arrhythmia? 3. A patient is being examined for life-threatening low blood pressure. Under questioning, the patient admits to having taken Viagra, an erectile dysfunction drug, in spite of already taking high blood...
During the pacemaker potential in pacemaker cells _____ through voltage gated channels A. Ions enter cells down concentration and charge gradients B. Ions exit cells down concentration but with charge gradient C. Ions exit cells down concentration and charge gradients D. Ions enter cells down concentration but against charge gradient Please try to explain the reason,ty.
In a heart pacemaker, a pulse is delivered to the heart 81 times per minute. The capacitor that controls this pulsing rate discharges through a resistance of 2.5 x 106. One pulse is delivered every time the fully charged capacitor loses 59.7% of its original charge. What is the capacitance of the capacitor?
Describe the origin of the cardiac contraction signal and the pathway it follows through the heart.
A cardiac pacemaker can be affected by a static magnetic field as small as 1.7 mT. How close can a pacemaker wearer come to a long, straight wire carrying 18 A?