 The cranial nerves provide us with sight, sound, taste, smell, and much more. We'll be drawing them from the brainstem, here, outwards. But first let's draw out all of their foramen, the holes in the skull through which they pass. Here is the ethmoid bone. On top of it sits the frontal loben beneath it, the nasal cavity. The ethmoid has lots of little holes running through it, which are here known as the cribriform plate. Cribriform literally meaning like a sieve. Here is a rough version of the sphenoid bone. It has many holes, four of which are relevant for us. The optic canal is the most superior. Lateral to it is the superior orbital fissure, which is a break between the greater and lesser wings of the sphenoid. We also have the foramen ovale, which is oriented up this way. Then medial and anterior to that is the foramen rotundum. O for ovale, rho for rotundum. This is the temporal bone here, which has a hole called the internal acoustic meatus. And this is the occipital bone. Between these two there is a fissure of sorts called the jugular foramen. The big hole in the bottom of the occipital bone is the foramen magnum. And there is one more foramen just here called the hypoglossal canal. So now that we have the foramen mapped out, let us begin our cranial nerves. Cranial nerve number one, the olfactory, goes through the crib reform plate. Cranial nerve two, the optic nerve, crosses over like this, then goes through the optic canal. As you can see, we will only draw them on one side just to keep things simpler. Number three, the oculomotor, goes from the front of the midbrain through the superior orbital fissure. Number four goes from the back of the midbrain, then through the superior orbital fissure as well. That's the trochlear nerve. Number five starts at the pons, then frustratingly has three different branches. One goes through the superior orbital fissure, that's the ophthalmic branch. One through the foramen rotundum, that's the maxillary branch. And one through the foramen ovale, that is the mandibular branch. Number six, the abducens nerve goes from the pons through the superior orbital fissure, the last cranial nerve to do so. Number seven goes from the pons through the internal acoustic meatus, and that's the facial nerve. Number eight goes from just next to number seven through the internal acoustic meatus, then ends up at two different parts of the inner ear, the vestibule and the cochlea. That is the vestibulocochlear nerve. Number nine, the glossopharyngeal goes from the medulla through the jugular foramen, and the vagus nerve, number ten, does the same. Number eleven, the accessory nerve starts partly in the medulla and partly in the spinal cord. These two bits join up, and then it heads through the jugular foramen as well. Cranial nerve number twelve starts in the medulla and goes through the hypoglossal canal. I've drawn our cranial nerves in three different colours to highlight something important about their structure. Four go from the midbrain and brain, four from the medulla and four from the pons. That's one aspect which can help to simplify the structure of the cranial nerves in your mind. Check out our other videos on the cranial nerves if you would like a bit more detail. Hit subscribe and we will see you next time.