[MUSIC] So remember that there are only a few sources of brain tumors and the primary ones. First to all, the glia that are inside the brain can start to multiply. And the glia can multiply anywhere. They can multiply in, in the cerebral cortex and cerebellar cortex in the deep white matter. There's a basically it cannot particular predict where the glia is going to multiply. So brain tumors can occur anywhere in in the brain if they are gliomas. Multiple glial cells that are multiplying. There are two sources of glandular cells that, multiply. One is the pineal gland. This is this midsagittal section. Here's the hindbrain, here's the hindbrain, the midbrain and the forebrain. And right here at the front end of the midbrain is this attachment. And this is, this is half the pineal gland. It's been cut exactly in half. And it attaches right here. And these pineal cells can multiply and take up space and make a brain tumor. The other gland that's inside of the cranium and that can make problems is the pituitary gland. And remember that it attaches right here beneath the, it attaches right here beneath the optic chiasm. So, the attachment is right here. And these pituitary cells can also multiply. And that's called a pituitary adenoma. So we've got gliomas, we've got, tumors of, of glandular cells. In addition we can have tumors of the meninges, these are called meningiomas. And they can be, so the meninges are everywhere and so you never particularly know where the meningiomas are going to be located. There's one there's one more common source of these tumors and that is the myelin producing glial cells that surround cranial nerves. Now, I realize that I just said a lot of stuff. That may not be understandable to everyone. But we're going to look here. We're going to look here. Here's the cerebellum, here's the ponds, here's the madella, and way over here on the side are these little nerves. These are cranial nerves. They are exiting the brain stem between the ponds and the medella. Do you see these two nerves? So this one out here. This is the one that's going to the inner ear and it's going to be responsible for hearing and balance, vestibular sense. And this one right here is the one that goes to the muscles of facial expression. So what happens not uncommonly is that the glial cells that make the myelin for this vestibulocochlear nerve. The nerve that's going off to the inner ear, they become, they multiply. And they become cancerous. So, when that happens, they it, it produced dysfunction of first the vestibular function. So there's a problem with balance and then there might be a problem with hearing. And eventually as this gets bigger and bigger, it will start to press on the facial nerve, and there will be problems with making facial expressions. This is called, they, they used to call it an acoustic neuroma, and now people tend to call it a vestibular neuroma. It is, in fact, a, not a neuroma, it's not of a neuron, but it's a schwannoma. It's a tumor of the schwann cells. The schwann cells are the ones that make the myelin for these nerves. [MUSIC]