Chapter 8, End of Chapter, Review Questions, Exercise 1

The taste of the food ranges between sweet, sour, salty and bitter. The sweet sensation is perceived by the tongue tip, bitter taste is perceived at the posterior region of the tongue whereas the sides of the tongue are responsible for the salty and sour tastes.

The other sensory factors that help in determining the perception of food are smell, texture, and temperature of food. 

1. Smell: 

The olfactory epithelium is responsible for the sensation of smell. Olfactory epithelium is innervated by a number of olfactory neurons which have chemoreceptor molecules. These receptors bind with the odorant molecules emitted from the food and send impulse to the brain that enables the individual to respond to the odorant. 

2. Temperature of food: 

The temperature of the food is detected by the thermoreceptors that enable the individual to differentiate between warm and cold food. 

3. Texture of food: 

The tongue enables us to perceive the tactile sensation while eating. As the food moves in the mouth while chewing, its texture is felt by the cheeks. The trigeminal nerve receives the input of the oral cavity and sends the impulse to the brain that helps to perceive the texture of the food.