"Origins of words" by Susie Dent, Countdown 05/09/17 (hippocampus)

I have to thank Janet Irving who tweeted to ask about the origin of the word "hippocampus", in the brain.She says she's always puzzled over that one. So I thought I would talk you through the different terms for parts of our brain, given how essential they are in our lives. I'm going to start with the thalamus which is the inner chamber of the brain, if you like. And that's exactly what it meant in Greek. And if you think about an ophthalmologist, it's got the same "thalam" element to it, and that's a person who look at the inner chamber of your eyes. So that's all related. The cerebellum is the little brain, because it's a part at the back that regulates muscular activity. And the "cer" bit  - the C-E-R - that looks back to the ancient root than mean "horn" or "head", and you'll find that in so many different words in English. It's relates to keratin, which is the substance you'll find in an animal's horns and hooves, it's related to alpenhorn, to cervix, to cork, Cpricorn, rhinoceros, unicorn, triceratops. You name it, it's there in many, many things as well as cerebellum. The cerebral cortex - the cortex originally meant the bark of a tree. It's relates, we think, to cork, the word cork. And then went on to mean the external shell or the husk of something, and the cerebral cortex is the outer, it's the grey matter, if you like, of the brain. The brainstem has the medulla, the pons and the midbrain, and they control the breathing, digestion, the heart rate, etc. And they connect the brain with the spinal cord and other parts of the body. So "medulla" was the Latin for "pith", of "marrow", so it was the inner substance of ehich somethin is made, hence, the white matter of the brain. And the pons, of course, is the bridge.That part of the brainstem resemles a bridge that connects two of the hemispheres in the brain. I've done everything but the hippocampus, which is probably the favourite. It sounds very strange, but it actually implies that you have a seahorse in your head, because the word comes from the Greek hippo campus, wich the hippo is a horse, of couse, the hippopotamus is the river horse, if you translate that from the Greek, and a campus meant "sea monster". It was the name of the crature ridden by the god Poseidon and it was later applied to the marine animal we now know as the seahorse and, of cause, the hippocampus brain structure got its namebecause it simply looks like a seahorse.