The human body has five senses that keep in touch with what is going on in the external world: touch, taste, smell, sight, and hearing. Below I will describe how these senses work.
Taste- The tongue is the body part that helps us sense taste. The tongue consists of taste buds (mushroom like projections) which are specific receptors for sense of taste. Each bud contains several cell types in microvilli that project through pores and chemically sense food. Gustatory receptor cells communicate with cranial nerve axon endings to transmit sensation to the brain. There are five taste sensations located on the tongue. They are sweet located front middle, sour located middle sides, salty located front side/tip, bitter located back, and umami located posterior pharynx. The cranial nerves that are associated with our taste sense are VII Facial located within the tongue, IX Glossopharyngeal located within the tongue, and X Vagus located within the pharynx. Taste likes and dislikes have homeostatic value. Taste is affected by many factors, and what is commonly referred to as our sense of taste depends on stimulation of our olfactory receptors by aromas.
Smell- The nose is the body part that helps us sense smell. The nose contains thousands of olfactory receptors which are receptors for sense and smell. When the olfactory receptors are stimulated by chemicals dissolved in the mucus they transmit impulses along the olfactory filaments, which are bundled axons of olfactory neurons that collectively make up olfactory nerve (cranial nerve one). The olfactory nerve conducts the impulses to the brain. There the odor is interpreted and an “odor snapshot” is made. Our reactions to odors are rarely neutral we tend to either like or dislike odors, and we change, avoid, or add odors according to our preferences.
Sight- The eyes make of the body part of our sight sense. Vision is the sense that has been studied most. The accessory structures of the eye include the extrinsic eye...
Please join StudyMode to read the full document