During the S-T segment, what is occurring within cardiac muscle cells?
A. Calcium is entering and potassium is leaving ventricular cells.
B. Potassium is entering atrial cells and sodium is leaving ventricular cells.
C. Sodium channels are beginning to open in ventricular cells and calcium is entering through slow channels in atrial cells.
D. Sodium is rapidly diffusing out of atrial muscle cells.
Answer: A
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Answer the following statement true (T) or false (F)
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