Which ion primarily enters cardiac muscle cells during depolarization?
What triggers the initial spike in the cardiac action potential?
What is the role of the SA node in the heart?
What channels are activated during the pacemaker potential?
What happens to K+ channels during the plateau phase of the cardiac action potential?
How does the AV node contribute to heart function?
What is the AV delay?
Which statement is true regarding cardiac muscle contractions?
What ion is primarily responsible for the rising phase of the action potential in the SA node?
During the cardiac action potential, what balances the K⁺ that leaks out of the cell?
What occurs when cardiac muscle cells are interconnected by gap junctions?
How does cardiac muscle differ from skeletal muscle in terms of stimulation?
What happens to the heart if the nerves that innervate it are destroyed?
A) The heart stops beating B) The heart continues to beat C) The heart beats irregularly D) The heart becomes paralyzed
What is the primary role of Purkinje fibers? A) To slow down conduction in the ventricles B) To provide rapid conduction in the ventricles C) To store blood D) To filter electrical impulses
What is a key feature of the cardiac muscle's action potential? A) It is short and quick B) It has a long duration C) It occurs only with neural input D) It does not involve Ca²⁺
What is the function of the SA node in isolated conditions? A) It beats at a slower rate B) It beats faster than the AV node C) It does not beat D) It becomes inactive
What happens to the membrane potential after K⁺ channels close? A) It rapidly depolarizes B) It hyperpolarizes C) It remains constant D) It repolarizes slowly
What is the primary influence on the rate and strength of cardiac contractions? A) Hormones B) Neural impulses C) Blood pressure D) Body temperature
What role does the connective tissue play between the atria and ventricles? A) It conducts electrical impulses B) It provides insulation
Question text is missing.
Which part of the heart is responsible for the fastest intrinsic rhythm?
What is the main consequence of the long duration of the cardiac action potential?
What is the main ion that enters the cell during the depolarization phase?
How does the cardiac action potential differ from that of skeletal muscle?
What happens immediately after the impulse passes the AV node?
Which ion's influx is primarily responsible for the plateau phase in cardiac action potentials?
What is the ionic flow during the pacemaker potential primarily due to?
What is the significance of the long refractory period in cardiac muscle?
What triggers the rapid rise in the pacemaker potential?
What is the primary function of the Purkinje fibers in the heart?
How does the heart ensure all parts of the ventricles beat in unison?
What happens to the cardiac action potential after it reaches the threshold?
What is the consequence of the AV node's function in the heart?
Which channels are primarily involved in the cardiac action potential?
What happens to the action potential cycle after reaching the threshold?
What is the main ion responsible for the plateau phase in cardiac action potentials?
What is the role of the SA node in the heart's conduction system?
How does the heart respond to the destruction of the nerves that innervate it?
What is the effect of the long refractory period in cardiac muscle?
What is the primary benefit of the cardiac cycle?