Physiology of Peristalsis

Explanation of the slow waves from Cajal cells, and the action potentials initiated by myenteric reflexes or parasympathetic stimulation.

[NewLysin]

Greetings from Germany, your video is far better than every german video on YouTube. I am studying animal science and we need this knowledge as well :)

[chriskoenig]

Great explanation!! I've found many of your videos extremely helpful during my studies. Just wanted to thank you for that and know that it is appreciated.

[manelbenzeghiba]

Thank you so much sir for this video, i wouldn't have understood if it wasn't for you .

[makanmir]

Some sources say that the longitudinal muscle relaxes above the bolus, allowing it to stretch, but you mentioned that it contracts. What are your comments on this?

[denised]

this explanation helps tons! thank you

[CapAdGroup]

I've been watching your whole GI series at 1.5x speed to review for my exam next friday, and so far it's going great!

Thanks so much!

[davidreppert]

How do you start peristalsis once you lose it due to pain injury disease Etc?

[alindmc]

too good..but isn't myenteric plexus situated in between circular and longitudinal muscle layers? and 1 thing i wanna understand is- the slow waves r generated in cajal cells, and how r they transmitted to the muscle fibres? is it like cajal cell to muscle cell?

[tundraweaver]

Brilliant Explanation. This helped me tremendously

[nabilh]

Thank you this is truly excellent, you are a great teacher!

[trifaiful]

amazing explanation, thank you so much, so is it safe to say that in the fasting state the GI motility is generated by cajal cells, and in the fed state stretch receptors will stimulate the postprandial GI motility? 

[vbt]

Thanks for the Vid But Let me ask if i got this correctly:


1- Sensory receptors relays to MYENTERIC plexus( upon Stretch or chemical acting on them)

2-.. the Interneurons of'' Myenteric Plexus'' Relay send '' Efferent'' Signal to Smooth muscle for contraction .

3-At same Time Cajal Cell are doing their thing with BER up and down spike, (slow Rhythm contaction ) , that are NOT enough to create Action potential but can make it easier by allowing Hyperpolarization state


4-the Afferent Signal Coming from the ''Myenteric Plexus'', will Cause Threshold Crossing (In hyperpolarized state ) leading to Action Causing Smooth muscle to contract.

to peristalsis ?


All Above is Done Purely withing the ENS '' Enteris Nervous system''
however the CNS can act via Parasympathetic ( Acetylcholine ) as stimulatory and inihibitory via Sympathetic (noerpinehphrine )?

Sorry for such a Long Question, But there are very few good sources that can explain what you did :) Thanks Again.

[umutarkan]

excellent video mr.wolf, ı have been investigating the gastrointestinal motility for a long time, ı am a medicine student, ı have some questions; if there isnt slow wave potential in smooth muscles, wouldn't peristalsis be? what is the importance of slow wave potentials?

[younottube]

thank you sir, very informative and easy to understand .... keep doing the good job <3

[allanvalladares]

very good video, but i have a question? the longitudinal muscular layer is the external layer and the circular one is the internal, thats what i had unsderstood, from the book of pathofisiology mcphee

[Baraa.K.Mohammad]

You rock Mr.Wolf!
But I got one question... How do the circular muscles infront of the bolus relax? I mean what's the mechanism?
Thanks.

[TheXplicitSyrian]

Good stuff professor! thanks. Question: CNS, parasympathetic via vegas is only involved to extra stimulate the interneurons that otherwise function normally on its on? If there was a lesion to Vegas right at the entry point to the GI it wouldn't stop peristalic reflex? 
Thanks - Med student. 

[hunfaasghar]

Thank you for the video !! I have a question about Cajal Cells. What I understood from lecture is that Cajal cells are constantly producing slow waves and they are NOT action potentials. Therefore, we can infer that a hormone or Neurotransmiiter is going to have no effect on slow wave amplitude and pattern?

[farahshbeeb]

Clears out many gaps jn understanding 👏 helpful !

[yankyuksel]

circular mus. is the closest to lumen i think there is a mistake