arachnoid mater

pia

My mum put this down in Words With Friends the other day, which prompted me to look it up as I’d only ever seen it as a woman’s name before and obviously proper nouns are NOT ALLOWED. Well, it turns out we all have a pia – it’s an anatomical term, the full version of which is ‘pia mater’. And it has quite an interesting backstory. (Disclaimer: I’m no biologist, so apologies if you are and I’ve got any of this wrong.)

The pia mater plays a vital role in keeping our central nervous systems healthy and functioning properly. It’s one of three meninges (sets of membranes that provide a protective covering) that surround and protect our brains and spinal cords. The other two are the dura mater and the arachnoid mater. The pia mater is the innermost layer that directly covers the surface of the brain and spinal cord. It’s a thin, transparent membrane that sticks closely to our brains’ contours, following the folds and grooves. It also surrounds the spinal cord.

The pia mater’s primary function is to support, protect and nourish the underlying neural tissues by carrying blood vessels that supply nutrients and oxygen to the brain and spinal cord. If you fall down a lot like I do, then you should be grateful to your pia mater, as it protects that brain and spinal cord from impacts.

We are of course here for the words, so why is it called a pia mater? If you did any Latin in school then you might be ahead of me here – it translates to ‘tender’ or ‘gentle’ ‘mother’ (the word ‘pia’ is the feminine form of the Latin adjective ‘pius’). The name ‘pia mater’ was introduced during the Renaissance period (14th to 17th centuries) when anatomical knowledge was expanding, and Latin was the universal language of science and academia, and has stuck around ever since. It was probably called that because of the way it encloses the surface of the brain and spinal cord, cradling them like a mother. Nice, right?

Oh, and you’ve probably guessed that ‘arachnoid mater’ translates as ‘spider-like mother’, because of its web-like appearance. And ‘dura mater’ means ‘tough mother’ due to this outermost meninge’s durable and robust nature. It’s one tough mother f*cker.