Olfactory cells are what let revelers enjoyed the scent of a fresh-baked treat, warn homeowners of gas leaks, allow drug-sniffing dogs to track down criminals, as well as being responsible for 90% of the sense of taste. Olfactory cells are nerve cells, part of the nervous system and classified as part of the peripheral sensory nervous system. They are located in the scent-sensing organs of humans and other animals, have a specific shape that is dependent on their specific location, and vary greatly in their number and sensitivity.
Olfactory cells are neurons, also known as nerve cells. They are part of the nervous system, a body system made of a vast network of nerves and electrochemical connections. The nervous system is responsible for gathering information from the surrounding environment, relaying this information to the brain, and transmitting the brain’s commands to the body. Their primary function is to gather sensory information related to the sense of smell. Because of this, and the fact that they are not located in the brain or spinal cord, they are classified as part of the peripheral sensory nervous system.
These cells are generally located in the nose and in other organs responsible for detecting scent stimuli. In humans, these cells are located in the olfactory epithelium, a densely-packed cluster of cells at the back of the nose. Other mammals such as dogs have a second set of olfactory cells located in the Jacobson’s organ. The Jacobson’s organ hangs in the back of the throat and helps give dogs their incredible sense of smell.
Olfactory cells have a specific shape dependent upon their location in the body. Cells located in the olfactory epithelium have an elongated shape with a knob on one end. By contrast, cells located in a Jacobson’s organ have a more rounded shape. Scientists are not yet sure of the reason behind these shape differences. There is speculation that the two different shapes work in a synergistic manner in animals that rely heavily on their sense of smell.
Finally, scent smells in both humans and animals vary in both their number and in their sensitivity. For example, humans have five million olfactory cells. Dogs, by contrast, have upwards of 220 million olfactory cells. Humans are capable of recognizing over 10,000 distinct scents. While it is not yet known how many scents dogs can distinguish, scientists suspect they can distinguish far more than humans can.