Papillae: Form and Function
Papillae are the tiny raised protrusions on the tongue that contain taste buds. The four types of papillae are filiform, fungiform, foliate, and circumvallate. Except for the filiform, these papillae allow us to differentiate between sweet, salty, bitter, sour, and umami (or savory) flavors.
Fungiform papillae are mushroom-shaped and scattered across your tongue's surface. Your tongue has between 200 and 400 fungiform papillae that range across the dorsum or top of the tongue but are mostly concentrated on the sides and the tip. Each papilla contains three to five taste buds, adding up to more than 1,500 receptors overall. The function of fungiform papillae is not just to detect flavor but also to sense temperature and touch.
Not only do your tongue's sensory cells help you to enjoy food, but they also help you avoid pain and poison. By sending information to nearby nerve fibers and on to the gustatory (taste-related) portion of your brain, papillae alert your body to dangers like rotten food, poisonous gases, or smoke.