2021 Pflugers Archiv : European journal of physiology
* Excitation-contraction coupling and calcium release in atrial muscle.
- In cardiac muscle, the process of excitation-contraction coupling (ECC) describes the chain of events that links action potential induced myocyte membrane depolarization, surface membrane ion channel activation, triggering of Ca2+ induced Ca2+ release from the sarcoplasmic reticulum (SR) Ca2+ store to activation of the contractile machinery that is ultimately responsible for the pump function of the heart. Here we review similarities and differences of structural and functional attributes of ECC between atrial and ventricular tissue. We explore a novel "fire-diffuse-uptake-fire" paradigm of atrial ECC and Ca2+ release that assigns a novel role to the SR SERCA pump and involves a concerted "tandem" activation of the ryanodine receptor Ca2+ release channel by cytosolic and luminal Ca2+. We discuss the contribution of the inositol 1,4,5-trisphosphate (IP3) receptor Ca2+ release channel as an auxiliary pathway to Ca2+ signaling, and we review IP3 receptor-induced Ca2+ release involvement in beat-to-beat ECC, nuclear Ca2+ signaling, and arrhythmogenesis. Finally, we explore the topic of electromechanical and Ca2+ alternans and its ramifications for atrial arrhythmia.
=>機能の, 関数の, 機能する, 機能上の, 実用的な, 機能的な
Overview of adj functional
The adj functional has 6 senses (first 2 from tagged texts)
1. (3) functional -- (designed for or capable of a particular function or use; "a style of writing
in which every word is functional"; "functional architecture")
2. (1) functional -- (involving or affecting function rather than physiology; "functional deafness")
3. functional -- (relating to or based on function especially as opposed to structure; "the problem
now is not a constitutional one; it is a functional one"; "delegates elected on a functional rather
than a geographical basis")
4. functional, usable, useable, operable, operational -- (fit or ready for use or service; "the
toaster was still functional even after being dropped"; "the lawnmower is a bit rusty but still
usable"; "an operational aircraft"; "the dishwasher is now in working order")
5. functional -- (designed for or adapted to a function or use; "functional education selects
knowledge that is concrete and usable rather than abstract and theoretical"; "functional
architecture")
6. running, operative, functional, working -- ((of e.g. a machine) performing or capable of
performing; "in running (or working) order"; "a functional set of brakes")
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