Assertion: pacemaker's action potential | /r/CapableOf | spread over the t tubule
Facets:
value: from the cell membrane
type: TRANSITIVE-OBJECT
Source sentences:
text: The sarcoplasmic reticulum serves as reservoir for calcium ions, so when an action potential spreads over the T tubule, it signals the sarcoplasmic reticulum to release calcium ions from the gated membrane channels to stimulate a muscle contraction.
text: - Action potential spreads from the cell membrane into the T tubules.