Essential oils are unique in that their efficacy begins at the aromatic level. Unlike pharmaceutical drugs, an essential oil need not be ingested, nor even applied like a medical cream, to affect your body to heal. The simple act of smelling an essential oil begins its work to heal the area of your body that requires attention.
Penetrating the brain barrier
The aromatic compounds in pure essential oils rise up the nasal cavity and are first detected by olfactory cells that are part of the olfactory epithelium. The olfactory cells are nerve cells with extended cilia (hair-like structures) which have receptors that bind to specific odour molecules. When a receptor binds to an odour molecule, the olfactory cell sends the signal through the cribriform plate (bone barrier between the nasal cavity and brain) to the olfactory bulb.
The olfactory bulb in turn sends impulses to five different structures in the brain. Each of these five structures has a different response to the impulse, and a specific function to undertake.
• The amygdala stores and releases emotions or trauma;
• The anterior olfactory nucleus processes odours;
• The olfactory tubercle is a multi-sensory processing centre however does not itself process odours;
• The piriform cortex sends signals to other structures; and
• The entorhinal cortex processes stimuli before sending them to the hippocampus, the memory centre of the brain.
The olfactory system is anatomically closely connected to the lymbic system of the brain, as shown by the following structures that make up the lymbic system. You can clearly identify the correlation between the olfactory and lymbic systems of the brain by the function of each structure.
• The hippocampus is the memory centre of the brain—it is important in the consolidation of information from short-term memory to
long-term memory and spatial navigation;
• The amygdala is involved with the experiencing of emotions—the storing and releasing of emotional trauma;
• The hypothalamus coordinates both the autonomic nervous system and hormones—body temperature, thirst, hunger, sleep and emotional activity; and
• The cingulate gyrus is involved with emotion formation and processing—learning and attention, regulating heart rate, blood
pressure and respiratory control.
Simply through aromatic use, essential oils can have immense physiological and psychological effects. They contain aromatic compounds from nature, that, in many cases, provide nourishment, growth, protection and healing to the plant itself. Those same compounds have been found to work within the human body to similarly nourish, protect and heal.
Based on science, we understand that aromatically essential oils do have therapeutic or healing benefits to the human body.
In the next issue of Modewest, we’ll be exploring the Basics of Essential Oils Part 2: Topical, how the application of essential oils directly to the skin—neat (undiluted) or diluted in a cream or carrier oil—can provide natural, healing benefits to the human body.