BMS 870 Lecture Notes - Lecture 10: Thalamus, Endocrine System, Olfactory Tract
24 Dec 2017
School
Department
Course
Professor
Document Summary
Smells: warns of harmful substances, combines w/ taste for identifying foods. Organs of smell: at olfactory epithelium at upper nose. Sends olfactory axons through cribriform plate which is part of ethmoid bone. Inhaled air goes over nares which causes mixing + warming of air (indentations) -> rises up to epithelium -> wafts over and goes back down. Cilia of olfactory cells -> axons -> cribriform plate -> olfactory bulb thru olfactory nerve. Cribriform plate - thin sheet of bone in the ethmoid bone through which small clusters of axons penetrate, coursing to the olfactory bulb. Humans: weak smellers due to small sa of olfactory epithelium. Odorants olfactory g-protein -> adenylyl cyclase converts atp to camp -> camp opens. Ca2+ channel -> releases ca2+ inside neuron -> causes cl- channel to open = membrane depolarization. Individual orns express only 1/1000 odorant receptors: orns that express the same odorant receptor send their axons to same olfactory bulb glomeruli.
