We have good understanding of the sensory side and some motor (like the coastlines of a continent) but have missing and limited understanding of the middle parts. (integration) Ramon y cajal- brought the concept of the neuron. Simple minds studying simple brains allows more easier learning about system since our brain is more complex. E. g. you don"t get burned on the same thing twice to learn not to touch it again. Olfactory smell helps on most identify things e. g. danger (survival) Bitter should be avoided poison survival we learn to enjoy but primitive is survival. But also use other senses e. g. taste and smell. Tongue, pallet, pharynx all have taste receptors. Tongue is the organ of taste specifically papillae. The tip of the tongue is sweetness. Papillae are used to increase the surface area of the taste on tongue. Tastebuds on the top or side of papillae. Microvilli allow to sense taste using receptor potential.