Plica Semilunaris

Medical Topic of the Day:  Our series of misunderstood body parts of dubious utility continues today with the plica semilunaris.

Off the Top of My Head:  I don't even know what that is.  In Latin it means "the fold of half of the moon." It has something to do with your eyeholes I think.

It is that thing apparently.

My Research Today:  The plica semilunaris of the conjunctiva is a small lose fold of bulbar conjunctiva on the inside corner of your eyes.  It is all that remains of the nictitating membrane of our ancestors.  But what is a nictitating membrane?

That is super sexy right there.

You know when cats lick each other's eyeballs?  You ever wonder why their eyes don't get all jacked up from that?  It is because they have a third eyelid which is translucent and can be drawn across the eye to moisten and protect it.

Amphibians, fish, birds, reptiles, many of them have nictitating membranes.  Primates, not so much; only the calabar angwantibo has them.

That is a calabar angwantibo.  It is less
exciting than I thought it would be.

Fun fact:  When I was a kid I once stuck the eraser end of a pencil in my eye and jammed it between my eyeball and my orbit. It was an accident but it hurt like hell.  No one believed me but it really happened.  I let go of the pencil and it just stuck there.  I had to pull it out.  A nictitating membrane would have come in handy.  It is a shame we don't have them anymore.  To be honest it is lucky I can even see right now.

Right in there.  Still don't know how I did that

Well, that was fun.  Have a good night.

Quest To 180:
9K steps.  Tried to get into the pool tonight but it was like 93 degrees.  It was...not refreshing.


The MAN:
Meh