How can we smell things? I do not have a nose. So, how will I know? At the back of our nose, there is a tissue
called olfactory epithelium. It is covered with mucus. This tissue has specialized neurons called olfactory receptor neurons. There are about 40 million olfactory receptor neurons. These neurons are chemoreceptors, that is, neurons which detect chemicals. Wow. They have a cool name. Now, when any substance releases its smell or odor, the odor consists of chemicals. When we breathe in, these chemicals enter our nose. When they reach the olfactory epithelium. The chemicals get stuck in the mucus causing them to activate the neurons. As a result. These activated neurons send
signals through the olfactory tract to the brain. Informing it about the smell.