288 Introduction to Anatomy & Physiology to enhance their taste. Some scientists have also proposed fat, termed oleogustus, as a sixth basic taste. Although a single gustatory cell responds to only one taste sensation, individual taste buds contain 50 to 100 gustatory cells, which typically include all of the taste sensations. The flavors that you detect in food and beverages are influenced by sensations from your taste buds, but they are also strongly influenced by your sense of smell. An estimated 75% to 90% of what you may attribute to taste is actually due to what you smell. In the absence of smell, you would be able to distinguish only the five basic tastes—sweet, salty, sour, bitter, and umami. But the average person is able to distinguish approximately 10,000 different flavors. The human mouth contains no taste receptors for the distinctly recognizable tastes of peach, tomato, lime, or chocolate, for example. Each of these flavors is produced by a combination of taste and smell. The brain receives sensory information from the receptors for both taste and smell, and then translates this information into the flavors that you recognize (Figure 7.21). Flavor is actually a combination of taste, smell, texture or consistency, and temperature. Many people have aversions to food and beverages whose consistency they simply do not find appealing. A hot food or drink gives off odors that strongly activate the neural pathways for smell, whereas the same food or beverage, when cold, gives off a much weaker odor, making it less appealing. Gustatory Sense The sense of taste is referred to as the gustatory (GUS-ta-toh-ree) sense. The human mouth contains approximately 10,000 sensory receptors for the sense of taste. These taste buds, or gustatory receptors, are scattered throughout the interior of the mouth, including the lips and the sides, top, and back of the mouth. Most of the taste buds, however, reside on the familiar tiny bumps on the tongue known as papillae (pa-PIL-ee). Within each taste bud, tiny gustatory hairs run up through the taste pores, very small openings in the top of the taste buds (Figure 7.20). When you eat food, the food is mixed in your mouth with saliva, which is produced by the salivary glands in the mouth. Chemical molecules from food dissolve in the saliva to produce compounds called tastants (TAYS-tehnts). The tastants stimulate the gustatory hairs to send nerve impulses to the brain. Three of the cranial nerves—the facial nerve, the glossopharyngeal (glahs-oh-feh-RIN- jee-al) nerve, and the vagus (VAY-gus) nerve—are responsible for transmitting taste sensations to the brain. Refer to Chapter 6 for more information about these nerves. Types of Flavors Although people enjoy many foods and beverages because of the complexity of the taste sensations they generate, the gustatory sense comprises only five basic tastes. These are sweet, salty, sour, bitter, and umami. Umami is the taste of beef as well as the taste of monosodium glutamate, a seasoning commonly added to processed foods © Body Scientific International Figure 7.20 Anatomy of a taste bud. TongueTongue Afferent nerve Gustatory hairs Taste pore Gustatory (taste) cells Papillae on surface of tongue Andrey_Kuzmin/Shutterstock.com Figure 7.21 These children seem to be enjoying their ice cream cones. What factors contribute to the tastes and flavors they are experiencing? Copyright Goodheart-Willcox Co., Inc.