Middle School Life Science: Controlling the Body - The Senses — Flashcards

A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of stimuli. Although in some cultures five human senses were traditionally identified as such, many more are now recognized.
Touch is the ability to sense pain, pressure, or temperature. Nerve cells that sense touch are found mainly in the skin.    
The skin on the palms, soles, face, and lips has the most neurons. Neurons that sense pain are also found inside the body in the tongue, joints, muscles, and other organs.    
The sense of taste is controlled by sensory neurons on the tongue. They are grouped in bundles called taste buds.    
Taste neurons sense chemicals in food. They can detect five different tastes: sweet, salty, sour, bitter, and umami, which is a meaty taste. When taste neurons sense chemicals, they send messages about them to the brain. The brain then decides which of the five basic tastes you are detecting.    
The sense of smell also involves sensory neurons that sense chemicals. These neurons are found in the nose, and they sense chemicals in the air. Unlike taste neurons, smell neurons can detect thousands of different odors. Your sense of smell plays a big role in your sense of taste. You can use your sense of taste alone to learn that a food is sweet. However, you have to use your sense of smell as well to learn that the food tastes like apple pie.