Despite sounding like the latest indie band, The Turbinates are actually a labyrinth of thin bones inside your dogs long nose that contribute to your dogs amazing ability to smell.
How Your Dog’s Super Nose Works…
Olfaction begins with sniffing and a dog’s nose is structured in a way to enable it to be very precise and skilful.
The dog has two nostrils divided by a cartilaginous and bony septum. The tip of the dog’s nose – rhinarium – is typically moist and cool to touch. This moist spongy outside captures any scents in the air.
Having two nostrils means dogs can smell ‘in stereo’ which helps them determine the direction the scent is coming from. When a dog uses its nostrils to sniff, air enters the nose and is divided into two separate folds: one for breathing, and one for deciphering scent. Dogs exhale through these slits at the side of their nose which generates swirls of air that help draw in new odour molecules and allow odour concentration to build up as the dog continues to sniff.
This is why dogs will often be seen with their heads held up high repeatedly sniffing the air.
The dog’s long nose contains a labyrinth of thin bones, called turbinates. The Turbinates are bony ridges covered with mucus membranes that provide a very large surface area for the air breathed to pass over and therefore slow down the flow of air entering the nose.
Dogs possess another olfactory chamber called Jacobson’s organ, or, vomeronasal organ. Tucked at the bottom of the nasal cavity, it has two fluid-filled sacs that enable dogs to smell and taste simultaneously.
The posterior part of the dog’s nose is lined with epithelium which contains the scent receptors. To gain maximum contact, with the air containing the odour the neurones have hair-like projections (cilia). Mucus helps to trap and absorb the scent particles inside the nasal chambers and diffuses them to the cilia of the scent receptors. This interaction generates nerve impulses that send messages by the olfactory nerves to the fore- brain area. The area dedicated to olfaction – The Olfactory Bulb. It is responsible for processing scents detected by the cells in the nasal cavity and is approximately 40 times larger in dogs than in humans.
“We might notice if our coffee’s been sweetened with a teaspoon of sugar; a dog can detect a teaspoon of sugar in a million gallons of water: two Olympic-sized pools full.” Alexandra Horowitz, ‘Inside of a Dog”
Scent information travels from the Olfactory bulb to the limbic system which then interprets the odours in combination with other specialised areas of the brain.
As different scents are transported to different parts of the brain, different regions of the brain are responsible for making sense of the information, such as emotions and memories. The information travels to the cerebral cortex and onto the Hypothalamus Amygdala (limbic system) which is responsible for emotion. The amygdala passes emotional experiences to other structures that gather memories and these are passed onto the cortex.
When a scent and memory are paired an emotion is usually recalled and that will be remembered for future reference. If a dog has already smelt that scent before, the emotion it associates with it will be displayed.
For scent training, when perception of an odour is associated with a positive reward, this contributes to the motivation of the dog to find the odour.