Xylem and phloem fiber cells
Humans ferment lactic acid in muscles where oxygen becomes depleted, which is why sometimes if you finish a run and don't stretch soon you have have discomfort. <span />
I think it’s D i hope i’m right
<span>Sodium channels close when not occupied
</span><span>Sodium ions diffuse through and enter the cell.
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Then they leave the cell.
The sodium diverts in the cell layer have receptor locales for acetylcholine.
