| SNCL | sinus node cycle length |
|---|---|
| Tc | cytotoxic T-cell; the generation time of a cell cycle; tricuspid closure |
| tG1 | the time required to complete the G1 phase of the cell cycle |
| tG2 | the time required to complete the G2 phase of the cell cycle |
| tM | the time required to complete the M phase of the cell cycle |