Anatomy | Mechanisms of Smooth Muscle Contraction

[@AimeeTrainor-ic4yj]

this is the best video ive ever watched on this; thank you so so much!!

[@hughs2525]

very helpful and just at the right level of detail, commenting to help the yt algorithms

[@luba7866]

Discovered your channel recently! Amazing indeed!

[@БОРКИША-КРЪСТНИКЪТ]

Thank you, sir

[@ttho4462]

Hi, thanks for the video! I am a little confused because I have been reading and learning about the effects of theophylline on bronchioles. From my understanding, it is a phosphodiesterase inhibitor, thus leading to an increase in cAMP concentration in smooth muscle. I have also read that cAMP inhibits myosin light chain kinase thus causing bronchodilation/ SM relaxation. I am confused because now it seems contradictory if cAMP is shown here to induce release of calcium ion from SR. Please can you help?

[@hanyelhag1664]

You are right , from what I know cAMP cause smooth muscle relaxation by the mechanism you just mentioned , while cGMP cause relaxation by activating myosine light chain phosphatase ( through the action of protein kinase G) . Epinephrine cause smooth muscle contraction through its action on alpha 1 receptor ( Gq ) while it can cause smooth muscle relaxation through B2 ( Gs - cAMP) .. so I'm as confused as you .

[@kyforever0551343]

I think there is a mistake with epinephrine, it works on Gq which in turn activates Phospholipase C(PLC) which then hydrolyses PIP2 giving DAG and IP3..IP3 induces the release of Ca+ etc.

[@randdawoud5960]

Thank you so much, amazing explanation!!!

[@jamesofosuhene4570]

Finally got someone who made this understandable 😂

[@TheHyperMD]

Hmmm - - cAMP (via NE/Epi, beta 2, Gs)-> smooth muscle relaxation. - IP3 (via NE/Epi, alpha 1, Gq)-> smooth muscle contraction. - inhibition of cAMP (via NE/Epi, alpha 2, Gi)-> smooth muscle relaxation.

[@jushnita.]

How good you explained I couldn't expess!!!!!!!!!

[@CassieKadrlik]

how does the actin myosin light chain get unphosphorylated what reverses it?

[@JAMScover1]

Very helpful!! Thanks

[@oceanemassambambe8762]

so helpful thank you !!

[@CatalystUniversity]

You're very welcome!

[@ksnvkrishnaveni7857]

Thanks bro....

[@jadathomas3684]

tyyyyy