Excitation-Contraction Coupling in Heart muscle cells
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- Опубліковано 2 чер 2024
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This video tutorial reviews EC coupling in Heart muscle cells:
0:00. Introduction
0:55. The anatomy of EC coupling
3:44. 1. AP propagates along membrane, down T-Tubule and activates L-type Calcium channel
4:02. 2. Ca flows into cell and binds to and activates the RyR receptor
4:20. 3. Enables SR to release Ca into the cytoplasm (Ca transient)
- 4:49. Guinea pig heart muscle cell contraction with Ca dye
5:40. 4. Rise in cytoplasmic Ca activates the myosin and actin to contract
6:02. Cytoplasmic Ca must decline for cell to relax (SERCA, NaCaX, Ca pump)
6:57. EPI and CCB influence on L-type Ca channels
7:40. In-A-Nutshell
8:21. Acknowledgements
I'm so glad you put down the DHP channel name, that cleared up so much on CCBs esp the non DHP and DHP kinds.
Interesting note:
Extracellular calcium entry is not largely required for skeletal muscle contraction(which also has L type ca and RyR channels). In skeletal muscles, the L type ca channels have mechanical coupling with RyR channels. An AP will cause a conformational change in L type channels which in turn leads to opening of RyR because of their mechanical link.
This mechanical coupling is not found in cardiac and smooth muscle cells.
This explains why CCB ,which blocks L type ca channels and block EC calcium entry, affect the heart and vascular smooth muscle but not skeletal muscles.
Studying for my exams and loved to share. Hope it helps.
Thanks Dr Morton for the amazing videos.
first attendance💯
Cool stuff but i didn't understand a thing 😂
:)