Answer and explanation;
The 4 main types of ion channels associated with cardiac muscle include;
- leaky Na+ channels
- voltage sensitive K+ channels (varying types)
- Ca2+ T type (transient or fast channels)
- Ca2+ L type (long or slow channels)
Ion channels help maintain ionic concentration gradients and charge differentials between the inside and outside of the cardiomyocytes. They are only permeable to a single type of ion based on their physical configuration.
-Specific channels open and close as the transmembrane potential (TMP) changes during cell depolarization and repolarization, allowing the passage of different ions at different times.
-Some ion channels (importantly, fast Na+ channels) are configured to close a fraction of a second after opening; they cannot be opened again until the TMP is back to resting levels, thereby preventing further excessive influx.