The trigeminal nucleus (40X)

The trigeminal nerve is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves. It arises from the anterolateral surface of the mid-pons as a large sensory root (portio major) and a smaller motor root (portio minor). All sensory information from the face, both touch-position and pain-temperature, is sent to the spinal trigeminal nucleus as seen in this image.

The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. Neurons of the reticular formation, particularly those of the ascending reticular activating system, play a crucial role in maintaining behavioral arousal and consciousness.