Podcast
Questions and Answers
What is the primary mechanism by which smooth muscle cells contract?
What is the primary mechanism by which smooth muscle cells contract?
- By a sliding-filament mechanism (correct)
- Through the use of tropomyosin
- Through the release of calcium ions from the mitochondria
- Via the binding of actin to troponin
What is the effect of phosphorylation of smooth muscle myosin?
What is the effect of phosphorylation of smooth muscle myosin?
- It increases the rate of ATP splitting
- It allows myosin to bind to actin and undergo cross-bridge cycling (correct)
- It inhibits the binding of Ca2+ by calmodulin
- It reduces the tension produced per unit cross-sectional area
What is the role of the sarcoplasmic reticulum in smooth muscle contraction?
What is the role of the sarcoplasmic reticulum in smooth muscle contraction?
- It is involved in the regulation of smooth muscle relaxation
- It is the primary source of ATP for smooth muscle contraction
- It is responsible for the release of calcium ions into the cytosol (correct)
- It is the site of smooth muscle myosin phosphorylation
What happens to the tension produced by smooth muscle when cytosolic calcium ions are increased?
What happens to the tension produced by smooth muscle when cytosolic calcium ions are increased?
What is the characteristic of smooth muscle myosin that differs from striated muscle myosin?
What is the characteristic of smooth muscle myosin that differs from striated muscle myosin?
What is the role of calmodulin in smooth muscle contraction?
What is the role of calmodulin in smooth muscle contraction?
What type of channels are responsible for the influx of calcium ions during the rising phase of the smooth muscle action potential?
What type of channels are responsible for the influx of calcium ions during the rising phase of the smooth muscle action potential?
What is the term for the spontaneous, periodic depolarizations of the membrane potential seen in some smooth muscle pacemaker cells?
What is the term for the spontaneous, periodic depolarizations of the membrane potential seen in some smooth muscle pacemaker cells?
What is the characteristic of smooth muscle cells in terms of their response to neurotransmitters?
What is the characteristic of smooth muscle cells in terms of their response to neurotransmitters?
What is the main difference between smooth muscle cells and cardiac muscle cells in terms of their structure?
What is the main difference between smooth muscle cells and cardiac muscle cells in terms of their structure?
What is the term for the type of smooth muscle that can generate action potentials in the absence of any external input?
What is the term for the type of smooth muscle that can generate action potentials in the absence of any external input?
How do smooth muscle cells differ from skeletal muscle cells in terms of their response to neurotransmitters?
How do smooth muscle cells differ from skeletal muscle cells in terms of their response to neurotransmitters?
What is a key difference between cardiac muscle excitation-contraction coupling and skeletal muscle excitation-contraction coupling?
What is a key difference between cardiac muscle excitation-contraction coupling and skeletal muscle excitation-contraction coupling?
What is a characteristic shared by cardiac muscle and smooth muscle?
What is a characteristic shared by cardiac muscle and smooth muscle?
What is a key similarity between cardiac muscle and skeletal muscle?
What is a key similarity between cardiac muscle and skeletal muscle?
What is a feature of cardiac muscle contractions that is not seen in skeletal muscle?
What is a feature of cardiac muscle contractions that is not seen in skeletal muscle?
What can be said about the comparison of skeletal, smooth, and cardiac muscles?
What can be said about the comparison of skeletal, smooth, and cardiac muscles?
