Author: Harshada, Learner at The Integral School, Hyderabad
All living things get information from the outside world. This information is received through sense receptors. Humans have five sense receptors that include vision, smell, taste, touch, and hearing.
Let us look at the touch receptors. Human bodies are covered with skin tissue. Our skin receptors send information to the brain to make sense and to remember. For example, if you are working in the kitchen and you cut your finger, you will feel pain and your brain will remember it as pain. The next time you work in the kitchen, you will be more careful and you will remember.
The receptors that help us to see are called photoreceptor. Humans have two kinds of photoreceptor that are called rods and cones. The rods and cones are in the back of your eye. The rods help you see properly. For example, when you are in a room and the lights are dim, you can see because of the rods. The cones help us see colour. For example, for your cones are weak, you may see a red apple as a green one.
Olfactory receptors are the ones that hope us smell. The receptors which help to smell are seven centimeters above the nose. When you have a cold, the smell molecules cannot smell properly because your nose is very stuffed and the molecules cannot reach the receptors. Dogs can smell better than us because they have many more cilia than us. That is why people use dogs for smelling things and finding them. Smell is the strongest sense of all our senses. When I went to Chilli’s, I ate a dessert and whenever I eat that dessert, I remember Chilli’s and I remember it because of the smell.
Receptors in the ear are called auditory receptors or hair cells. Air helps us hear because the sound waves travel through air. When the sound waves reach the ear, the ear drum vibrates and the bones in the ear also start vibrating. The cochlea starts vibrating and the receptors in the cochlea send information to the brain.
Humans have five types of taste: sour, sweet, salty, bitter and umami. An other taste is a combination of these tastes. A human has 10,000 taste buds and each taste bud has 50 to 150 receptors in them. Each taste bud lives for only 2 weeks. Taste buds are located on the tongue, back of mouth and on the throat. Animal receptors aren’t like humans. If you give cats sweet food, they may not like it because they cannot taste sweet things.
Different animals have receptors in different places on their body. Butterflies have taste receptors on their feet, the tongue of a rabbit has 17,000 taste buds, crickets can hear using their front legs, the box jellyfish has 24 eyes and elephants can hear and make very low frequency sounds. Whether you taste with your feet or tongue, hear with legs or ears, all of us need receptors. Without them, we wouldn’t know that much about the world around us.