Diaphragm: Which type of muscle fibers?

[stronghold]

---

Members do not see this ad.

I tried to search for answer, but did not find a definite answer. What do you think guys? I think it's type 2, but not sure.

 

[Tyrone Slothrop]

I tried to search for answer, but did not find a definite answer. What do you think guys? I think it's type 2, but not sure.

Both in equal distribution, and patients with COPD have a shift towards type 1.

 

[stronghold]

Thanks. Buy why in COPD it will be shifted towards type 1? is not supposed to be type 2 because more work load in COPD?

 

[mcloaf]

Type I fibers are more resistant to fatigue.

http://www.atsjournals.org/doi/pdf/10.1164/rccm.200701-020PP

 

[stronghold]

So is it different from the physiologic exercise induced shift from 1 to 2?

 

[Tyrone Slothrop]

COPD patients are tachypneic, so it's an exercise induced shift. Conversely their quadriceps shift to type 2 since they aren't being used as much.

 

[stronghold]

But why the case is reversed? I know that when we train (exercise), fibers shift from type 1 towards 2

 

[Tyrone Slothrop]

Think about your typical COPD patient, older and he definitely isn't walking around much. He's detrained. If you're asking about quadriceps.

If you're asking about diaphragm it's because they're basically endurance training their diaphragm. They're tachnypneic they're always breathing more than average. They aren't increasing force production they're increasing frequency.