Scheme of the olfactory system. (Left) Scheme of olfactory sensory neuron projections. Olfactory sensory neurons transduce odor information via electrical signals that trigger neurotransmitter release in the olfactory bulb. Mucus secreted by Bowman’s glands and sustentacular cells protect the olfactory epithelium’s structure and maintain homeostasis. (Right) Scheme of the olfactory system according to the process of olfaction.