Found this on the net:
Aromatherapy Use and Effects
In the upper realm of control of our body, moods, and state of balance, is our limbic system and hormones. Our hormones are produced in response to our perceptions. In psycho-somatic Aromatherapy (Aromachology), the aromatic properties of aromatic phytochemicals are used to: alter perception and therefore emotion and our hormonal balance, or, to facilitate emotional responses by directly stimulating the release of minute amounts of hormones. With our hormones and emotions/perception in balance, we experience wellness and/or a remission of psycho-somatic and nervous system related dis-ease. Therefore, you can find Aromatherapy effectively treating such varied functions as mood, emotion, co-dependent behaviors, sex, appetite, body temperature, digestion, blood pressure, the immune system, etc.
and also this:
Aromatherapy is the ancient practice of using essential oils extracted from plants to soothe imbalance of body, mind, spirit and emotions. In modern times we find that these highly concentrated "plant hormones" can have an effect on our organs, hormones and enzymes, a physiological effect on muscles, joints, and skin, and a psychological effect on elevating mood, sleep patterns, and reducing stress.
Don't know if this helps.....I think your teacher wants to know what the oils can do, in a same way that our hormonesdo ie.allevate our feelings, pains, mood etc