Frontal lobe of cerebral hemisphere Olfactory bulb Olfactory tract Cribriform plate of ethmoid bone Filaments of olfactory nerve (I) Nasal mucosa Anosmia (absence of sense of smell): head trauma,Parkinson's disease,virus infection,frontal lobe tumors Anosmia (absence of sense of smell): head trauma, Parkinson’s disease, virus infection, frontal lobe tumors