Podcast
Questions and Answers
What is the approximate resting membrane potential (RMP) for contractile cells?
What is the approximate resting membrane potential (RMP) for contractile cells?
- -90mV (correct)
- -60mV
- -30mV
- -40mV
Which ion enters the cell during phase 2 of pacemaker cells, contributing to its characteristic shape?
Which ion enters the cell during phase 2 of pacemaker cells, contributing to its characteristic shape?
- K+
- Cl-
- Ca2+ (correct)
- Na+
What type of channels drive the automaticity of the heart by enabling immediate regeneration of pacemaker potential?
What type of channels drive the automaticity of the heart by enabling immediate regeneration of pacemaker potential?
- K+ channels
- Sodium channels
- Funny channels (correct)
- Calcium channels
What is the approximate refractory period for the heart, allowing time for ion movements to enable restimulation of cells?
What is the approximate refractory period for the heart, allowing time for ion movements to enable restimulation of cells?
What does phase 0 of pacemaker cells rely on for depolarization?
What does phase 0 of pacemaker cells rely on for depolarization?
What happens when Ca2+ channels close in pacemaker cells?
What happens when Ca2+ channels close in pacemaker cells?
What allows cardiac muscle to fully relax before it can contract?
What allows cardiac muscle to fully relax before it can contract?
What is the approximate resting membrane potential (RMP) for pacemaker cells?
What is the approximate resting membrane potential (RMP) for pacemaker cells?
Which ion channels have slow kinetics in pacemaker cells?
Which ion channels have slow kinetics in pacemaker cells?
What is the purpose of the refractory period in muscle cells?
What is the purpose of the refractory period in muscle cells?
Why does the heart not need stimulus from the nervous system to beat when removed from the body?
Why does the heart not need stimulus from the nervous system to beat when removed from the body?
What is the main difference between pacemaker cells and neurons?
What is the main difference between pacemaker cells and neurons?
Why is it important for the heart to have a refractory period?
Why is it important for the heart to have a refractory period?
What role does conductivity play in the heart's function?
What role does conductivity play in the heart's function?
Why is it necessary for different parts of the heart to have different action potentials?
Why is it necessary for different parts of the heart to have different action potentials?
What is the role of Na+ gradient in muscle cell function?
What is the role of Na+ gradient in muscle cell function?
Why would it be detrimental for the heart to remain contracted for a prolonged period?
Why would it be detrimental for the heart to remain contracted for a prolonged period?
What is the significance of K+ concentration in muscle cells?
What is the significance of K+ concentration in muscle cells?
What happens if the hole in the ovales does not close after the fetus is born?
What happens if the hole in the ovales does not close after the fetus is born?
What is the average rate of flow when a person is at rest?
What is the average rate of flow when a person is at rest?
What organ has a high energetic demand despite not being the largest?
What organ has a high energetic demand despite not being the largest?
What allows for the increase in venous return during physical exercise?
What allows for the increase in venous return during physical exercise?
What is the approximate amount of blood in the average individual?
What is the approximate amount of blood in the average individual?
Where do the electrical events first occur in the heart?
Where do the electrical events first occur in the heart?
What system is referred to as a closed system with no leakage?
What system is referred to as a closed system with no leakage?
What is the source of oxygen for a fetus?
What is the source of oxygen for a fetus?
What happens if cardiac output increases during exercise?
What happens if cardiac output increases during exercise?
