Podcast
Questions and Answers
Which cells in the heart generate force and are connected by intercalated discs?
Which cells in the heart generate force and are connected by intercalated discs?
- Conduction cells
- Desmosome cells
- Sarcomere cells
- Work cells (correct)
What initiates the heartbeat in the heart?
What initiates the heartbeat in the heart?
- Work cells
- Sinoatrial node (correct)
- Desmosome cells
- Conduction cells
What is the role of the nerve supply in the heart?
What is the role of the nerve supply in the heart?
- To regulate the heartbeat (correct)
- To generate force
- To spread electrical events
- To initiate the heartbeat
What drives the beating of the heart?
What drives the beating of the heart?
What happens to the heart if it is not provided with oxygen and kept moist?
What happens to the heart if it is not provided with oxygen and kept moist?
Which node in the heart initiates the electrical impulse?
Which node in the heart initiates the electrical impulse?
What happens if the SA node is damaged?
What happens if the SA node is damaged?
What is the main cause of the AV delay in the heart?
What is the main cause of the AV delay in the heart?
Which fibers carry the electrical signal to the ventricle muscle cells?
Which fibers carry the electrical signal to the ventricle muscle cells?
Which type of action potential is exhibited by the SA node and AV node?
Which type of action potential is exhibited by the SA node and AV node?
Which channels are stimulated during hyperpolarization in slow response cardiac fibers?
Which channels are stimulated during hyperpolarization in slow response cardiac fibers?
What is the membrane potential during repolarization in slow response cardiac fibers?
What is the membrane potential during repolarization in slow response cardiac fibers?
What is the main characteristic of the pacemaker potential in slow response cardiac fibers?
What is the main characteristic of the pacemaker potential in slow response cardiac fibers?
Which node in the heart acts as the fastest pacemaker and can be influenced by the autonomic nervous system?
Which node in the heart acts as the fastest pacemaker and can be influenced by the autonomic nervous system?
During phase 0 of the action potential in working cells (ventricular cells), what causes depolarization?
During phase 0 of the action potential in working cells (ventricular cells), what causes depolarization?
What initiates repolarization during phase 1 of the action potential in working cells?
What initiates repolarization during phase 1 of the action potential in working cells?
What causes the plateau phase during phase 2 of the action potential in working cells?
What causes the plateau phase during phase 2 of the action potential in working cells?
What initiates rapid repolarization during phase 3 of the action potential in working cells?
What initiates rapid repolarization during phase 3 of the action potential in working cells?
Which type of muscle contraction requires intracellular support to induce contraction?
Which type of muscle contraction requires intracellular support to induce contraction?
What is the mechanism by which ryanodine receptors in cardiac muscles are operated?
What is the mechanism by which ryanodine receptors in cardiac muscles are operated?
What is the term for the process where the opening of ryanodine receptors allows more Ca in cardiac muscles?
What is the term for the process where the opening of ryanodine receptors allows more Ca in cardiac muscles?
What provides 90% of the intracellular Ca in cardiac muscles?
What provides 90% of the intracellular Ca in cardiac muscles?
Which type of channel blocker is commonly used to control force of contraction in cardiac muscles?
Which type of channel blocker is commonly used to control force of contraction in cardiac muscles?
Which part of the heart is primarily innervated by the right vagus nerve?
Which part of the heart is primarily innervated by the right vagus nerve?
Which part of the heart is primarily innervated by the left vagus nerve?
Which part of the heart is primarily innervated by the left vagus nerve?
Which part of the heart is lightly innervated by vagal efferent nerves?
Which part of the heart is lightly innervated by vagal efferent nerves?
Which receptors are activated by the parasympathetic nervous system in the heart?
Which receptors are activated by the parasympathetic nervous system in the heart?
Which receptors are activated by the sympathetic nervous system in the heart?
Which receptors are activated by the sympathetic nervous system in the heart?
What effect does the sympathetic nervous system have on the cardiac excitability of the fast response action potential in cardiac muscle?
What effect does the sympathetic nervous system have on the cardiac excitability of the fast response action potential in cardiac muscle?
What effect does the sympathetic nervous system have on the rate and rhythm of the fast response action potential in cardiac muscle?
What effect does the sympathetic nervous system have on the rate and rhythm of the fast response action potential in cardiac muscle?
What effect does the sympathetic nervous system have on the conduction speed of the fast response action potential in cardiac muscle?
What effect does the sympathetic nervous system have on the conduction speed of the fast response action potential in cardiac muscle?
Which ion is primarily responsible for speeding up the rate of pacemaker depolarization in the presence of sympathetic nervous system activation?
Which ion is primarily responsible for speeding up the rate of pacemaker depolarization in the presence of sympathetic nervous system activation?
What effect does the parasympathetic nervous system have on the rate of firing of the slow response action potential in cardiac muscle?
What effect does the parasympathetic nervous system have on the rate of firing of the slow response action potential in cardiac muscle?
Which channels are inhibited by the parasympathetic nervous system in order to slow down the rate of pacemaker depolarization?
Which channels are inhibited by the parasympathetic nervous system in order to slow down the rate of pacemaker depolarization?
Why does smoking increase the likelihood of a heart attack?
Why does smoking increase the likelihood of a heart attack?
Which type of muscle does not tetanize?
Which type of muscle does not tetanize?
During which phase of the action potential in working cells does depolarization occur?
During which phase of the action potential in working cells does depolarization occur?
What is the duration of the absolute refractory period?
What is the duration of the absolute refractory period?
What happens if a new stimulus occurs during the absolute refractory period?
What happens if a new stimulus occurs during the absolute refractory period?
What is the effect of the relative refractory period on the generation of an action potential?
What is the effect of the relative refractory period on the generation of an action potential?
