The Olfactory System

  What is the Olfactory System? It is important to know. The Olfactory System is basically the body's system of smell. Tiny molecules of aroma are inhaled by the nose. These aroma molecules are trapped in the nose by hairlike nerve endings that pass the aroma on to receptors that then carry the molecules to the Olfactory Bulb. From the Olfactory Bulb, the aroma molecules are transported to the limbic system in the brain. Sounds a little bit like an assembly line or a relay race. 

 And in all actuality, the Olfactory is just as efficient. In 1989, it was discovered that the Amygdala plays a very important role in storing emotional trauma. AND that odor triggers a profound effect from the gland. The theory (Dr. Joseph Ledoux, New York Medical University) being that odor can help release stored emotional trauma. 

The Olfactory nerves react as other nerves in the body do, responding to electrical signals and impulses and dispatching information to the rest of the body. This is how and why some oils can produce increased antibody production, as well as endorphins.

We perceive odors through thousands of olfactory nerves in our nostrils, which contain bundles of highly sensitive nerve cells. Unlike other nerve cells, these cells regenerate every 30 to 40 days. Specific aromatic molecules of essential oils react with specific nerve receptors, which in turn trigger electrochemical impulses that are conducted directly into the brain.

Aromas are transmitted to the limbic system, a part of the brain which perceives and responds to memory, pleasure and emotions. Odor triggers the limbic system to release brain-affecting chemicals known as neurochemicals. Enkephalin reduces pain and creates a feeling of well-being. Endorphins also reduce pain and induce sexual feelings. Serotonin helps relax and calm. Because the olfactory nerves are a direct extension of the brain's limbic system, recognition of smell is relayed immediately, whereas recognition of taste, sound and touch is not as immediate.

The olfactory system of the human brain has a lock and key mechanism for remembering scents. This creates an individual perception of aroma, different preferences for scents and specific memory responses. The lock is the actual smell memory; the key is the scent which opens the mind to the memory. In aromatherapy, the brain responds to the aroma of an essential oil by retrieving a past memory associated with the aroma. If the aroma is unfamiliar, the brain creates a new memory response. The memory responses can be relaxing, balancing, energizing, uplifting, etc. The sense of smell has the longest recall of all senses, so we tend to retain memories associated with aromas for quite some time.

Olfaction is unique amongst the senses in its direct connections to the neuroendocrine and limbic structures of the brain. This suggests that the olfactory system and olfactory stimuli may have potential uses in the treatment of various disorders, both physiological and psychological.

More on this subject:

The Olfactory System: Anatomy and Physiology

Molecular Analysis of Sensory Processing in the Olfactory System

The Olfactory Process and its Effect on Human Behavior

Olfactory System