Human muscle fiber under electron microscope.
https://s3-us-west-1.amazonaws.com/h...d_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...689#post193737
https://www.homemadetools.net/forum/...377#post192641
https://www.homemadetools.net/forum/...210#post188264
https://www.homemadetools.net/forum/...346#post192507
https://www.homemadetools.net/forum/...516#post158794
