Hi,
I've learnt that retraction and protraction are used to describe adduction and abduction, respectively.
However, when reading about the eyelids, FA says that "sympathetic fibers innervate smooth muscle of eyelids (minor retractors)".
The muscle they're referring to is m. tarsalis superior. This muscle keeps the eye open, and is thus abducting the eyelids. Isn't this a protraction then?
I've learnt that retraction and protraction are used to describe adduction and abduction, respectively.
However, when reading about the eyelids, FA says that "sympathetic fibers innervate smooth muscle of eyelids (minor retractors)".
The muscle they're referring to is m. tarsalis superior. This muscle keeps the eye open, and is thus abducting the eyelids. Isn't this a protraction then?