The group of modified cardiac muscle cells that delays action potentials between the atria and the atrioventricular bundle is called the
a. Purkinje fibers.
b. SA node.
c. bundle branches.
d. AV node.
e. apex.
Answer: D
Learn More :
Cardiovascular
- Excess K+ ions in cardiac tissue cause heart rate and stroke volume to __________ and decreased extracellular K+ ions result in a __________ in heart rate.
- Generally, an increase in extracellular Ca2+ ions causes __________ force of contraction, and __________ heart rate.
- Increased sympathetic stimulation of the heart
- If blood pH decreases and blood carbon dioxide increases,
- When normal arterial blood pressure decreases, baroreceptors cause a response that
- Parasympathetic nerve fibers
- Increased venous return to the heart causes increased
- Preload
- If the heart rate for a patient is 80 bpm, and her stroke volume is 70 mL/beat, then her cardiac output is
- The second heart sound, described as "dupp" is actually the sound of the
- During the period of ejection, the left ventricular pressure reaches a high point of approximately
- The average end-diastolic volume of the ventricles is about __________ , whereas the end-systolic volume is about __________ .
- At the end of __________ , the ventricles are 70% filled.
- Blood flows neither into nor out of the ventricles during
- During the period of ejection in the cardiac cycle, the atrioventricular valves are __________ and the semilunar valves are __________ .
- Which of these conditions is most likely to cause bradycardia?
- During the QT interval of the EKG, the
- In an EKG, the P wave represents
- Which of these conditions results in a prepotential in pacemaker cells?
- Unlike other cardiac muscle cells, the movement of __________ into the pacemaker cells is primarily responsible for the depolarization phase of the action potential.
- Which of these conditions occurs in the cardiac muscle cell during the final repolarization phase?
- Which of these conditions occur in the cardiac muscle cell during the plateau phase?
- Early repolarization of cardiac muscle cells occurs when
- The depolarization phase of the cardiac muscle action potential occurs when
- Action potentials pass rapidly from one cardiac muscle cell to another because of