Podcast
Questions and Answers
What is the role of ATP in muscular contraction and relaxation?
What is the role of ATP in muscular contraction and relaxation?
- ATP binds to troponin C to initiate muscle contraction.
- ATP breaks down to supply energy for muscular contraction and relaxation. (correct)
- ATP inhibits the binding of myosin to actin filaments.
- ATP is responsible for the release of calcium ions from the sarcoplasmic reticulum.
Which step involves the sliding of thin filaments over thick filaments in muscular contraction?
Which step involves the sliding of thin filaments over thick filaments in muscular contraction?
- Step 6: Shortening obtained by disconnection and reconnection of myosin heads. (correct)
- Step 1: Generation of action potential in myelinated motor nerve.
- Step 3: Release of calcium ions from the sarcoplasmic reticulum.
- Step 8: Reuptake of calcium by the sarcoplasmic reticulum to stop muscle interaction.
During muscular relaxation, what leads to the cessation of myosin and actin interaction?
During muscular relaxation, what leads to the cessation of myosin and actin interaction?
- Increase in troponin C levels in the muscles.
- Reuptake of calcium by the sarcoplasmic reticulum. (correct)
- Active release of ATP by the sarcoplasmic reticulum.
- Binding of calcium to troponin C.
Which process uncovers the binding sites of myosin on actin filaments during muscular contraction?
Which process uncovers the binding sites of myosin on actin filaments during muscular contraction?
Which structure is responsible for spreading action potential to the depth of myofibrils?
Which structure is responsible for spreading action potential to the depth of myofibrils?
In which step is more shortening obtained by disconnection, cocking, reconnection, and swiveling of myosin heads on actin filaments?
In which step is more shortening obtained by disconnection, cocking, reconnection, and swiveling of myosin heads on actin filaments?
What is the role of the sympathetic nervous system in cardiac muscle contraction?
What is the role of the sympathetic nervous system in cardiac muscle contraction?
How does physiological stimulation via sympathetic nerves affect the rate of relaxation in cardiac muscle?
How does physiological stimulation via sympathetic nerves affect the rate of relaxation in cardiac muscle?
Which protein undergoes phosphorylation due to the activation of β1-adrenoceptors?
Which protein undergoes phosphorylation due to the activation of β1-adrenoceptors?
How do drugs like milrinone and caffeine affect cAMP levels?
How do drugs like milrinone and caffeine affect cAMP levels?
What effect does increasing intracellular [Ca++] have on cardiac muscle contraction?
What effect does increasing intracellular [Ca++] have on cardiac muscle contraction?
How does phosphorylation of phospholamban influence Ca++ levels in the sarcoplasmic reticulum?
How does phosphorylation of phospholamban influence Ca++ levels in the sarcoplasmic reticulum?
Where does the majority of the Ca++ used to trigger contraction of cardiac muscle come from?
Where does the majority of the Ca++ used to trigger contraction of cardiac muscle come from?
In which type of muscle does the source of Ca++ for the contractile mechanism differ from cardiac muscle?
In which type of muscle does the source of Ca++ for the contractile mechanism differ from cardiac muscle?
What triggers an initial increase in intracellular calcium ion [Ca++i] concentration in cardiac muscle cells?
What triggers an initial increase in intracellular calcium ion [Ca++i] concentration in cardiac muscle cells?
What role do L-type calcium channels play in cardiac muscle contraction?
What role do L-type calcium channels play in cardiac muscle contraction?
Which component helps spread electrical excitation rapidly into cardiac muscle cells?
Which component helps spread electrical excitation rapidly into cardiac muscle cells?
What type of muscle uses only sarcoplasmic reticulum (SR) stores of Ca++ for contraction?
What type of muscle uses only sarcoplasmic reticulum (SR) stores of Ca++ for contraction?
