14 Questions
What is the main function of intercalated discs in cardiac myocytes?
Facilitating communication between cardiac myocytes
How do pacemaker cells in the heart differ from skeletal muscle cells?
Pacemaker cells can generate rhythmic impulses without external neural input
Which characteristic differentiates cardiac myocytes from skeletal muscle cells?
Presence of intercalated discs
What is the primary responsibility of pacemaker cells in the heart?
Initiating electrical impulses for heart contraction
Why is the branched structure of cardiac myocytes important?
It allows for efficient communication and synchronization of contractions
Which specialized structures are found at the junctions between cardiac muscle cells?
Intercalated discs
What is the role of sarcoplasmic reticulum in cardiac myocytes?
Storage and release of calcium ions for muscle contraction
What serves as the primary intracellular calcium store in cardiac muscle cells?
Sarcoplasmic reticulum
What triggers the release of calcium from the sarcoplasmic reticulum into the cytoplasm?
Extracellular calcium
Which channels embedded in the cardiac cell membrane permit the entry of a small portion of extracellular calcium into the cell?
Slow calcium channels
What percentage of the total calcium required for muscle contraction comes from the sarcoplasmic reticulum?
80-90%
Which organelle provides a reservoir of calcium ions ready for release during muscle contraction?
Sarcoplasmic reticulum
What initiates the process of muscle contraction by releasing calcium into the cytoplasm?
Extracellular calcium
Where are slow calcium channels embedded to allow the entry of extracellular calcium into cardiac cells?
Cell membrane
Test your knowledge on the characteristics of cardiac myocytes including their branched structure, striated appearance, and intercalated discs. Learn about how these features contribute to the efficient communication and synchronized contractions in heart muscle.
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