<P> The anterior olfactory nucleus distributes reciprocal signals between the olfactory bulb and piriform cortex . The anterior olfactory nucleus is the memory hub for smell . </P> <P> Loss of smell is known as anosmia . Anosmia can occur on both sides or a single side . </P> <P> Olfactory problems can be divided into different types based on their malfunction . The olfactory dysfunction can be total (anosmia), incomplete (partial anosmia, hyposmia, or microsmia), distorted (dysosmia), or can be characterized by spontaneous sensations like phantosmia . An inability to recognize odors despite a normally functioning olfactory system is termed olfactory agnosia . Hyperosmia is a rare condition typified by an abnormally heightened sense of smell . Like vision and hearing, the olfactory problems can be bilateral or unilateral meaning if a person has anosmia on the right side of the nose but not the left, it is a unilateral right anosmia . On the other hand, if it is on both sides of the nose it is called bilateral anosmia or total anosmia . </P> <P> Destruction to olfactory bulb, tract, and primary cortex (brodmann area 34) results in anosmia on the same side as the destruction . Also, irritative lesion of the uncus results in olfactory hallucinations . </P>

Where does transduction occur in the olfactory system