what causes striation?

[joonkimdds]

Kaplan blue book page 123 says " Skeletal muscle has striatiosn of light and dark bands, and is therefore also referred to as striated muscle.

DAT destroyer says that it's not because of light, dark bands but because of alternating between the thick and thin filaments.

which one is correct?

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[tinman831]

Kaplan blue book page 123 says " Skeletal muscle has striatiosn of light and dark bands, and is therefore also referred to as striated muscle.

DAT destroyer says that it's not because of light, dark bands but because of alternating between the thick and thin filaments.

which one is correct?

Both are correct. Skeletal muscle has striations when viewed under a microscope appear to look like light and dark bands due to the alternation between thick and thin filaments. What was the exact wording on DAT destroyer. You might have simply misinterpreted what it was saying.

 

[joonkimdds]

Both are correct. Skeletal muscle has striations when viewed under a microscope appear to look like light and dark bands due to the alternation between thick and thin filaments. What was the exact wording on DAT destroyer. You might have simply misinterpreted what it was saying.

it said
"the light band of the myosin interdigitating with the dark band of the actin"
but it was false statement.

 

[tinman831]

it said
"the light band of the myosin interdigitating with the dark band of the actin"
but it was false statement.

The myosin is supposed to be the dark band and the actin is supposed to be the light band.

 

[joonkimdds]

The myosin is supposed to be the dark band and the actin is supposed to be the light band.

Thanks 🙂
by the way, u know too much 😀

 

[tinman831]

Thanks 🙂
by the way, u know too much 😀

No I don't. I've been wrong before and I'm sure I'll be wrong some time in the future too.

 

[JohnDoeDDS]

just to make sure. The A band where the actin=thin and myosin=thick fibers overlap is the only zone that doesnt change length when the sacromere contracts right? Or is it the H band that doesnt change length?

 

[tinman831]

just to make sure. The A band where the actin=thin and myosin=thick fibers overlap is the only zone that doesnt change length when the sacromere contracts right? Or is it the H band that doesnt change length?

A band doesn't change length. You are correct.

 

[aranjuez]

just to make sure. The A band where the actin=thin and myosin=thick fibers overlap is the only zone that doesnt change length when the sacromere contracts right? Or is it the H band that doesnt change length?

Good question. The A band is what doesn't change. If you take a look at any diagram of a sarcomere, you can see that the overlap area can never change, as it encompasses all of the thick filaments (and of course, its overlap with the thin). The H zone is ONLY the thick filaments (i.e. myosin), and this region is variable with contractions, just as the I band is.

aranjuez