PNB 2264 Lecture Notes - Lecture 19: Olive Oil, Suspensory Ligament, Electromagnetic Radiation
Document Summary
Essential to survival, competition: olfaction, taste, sight, and hearing. Greater level of organization of sensory neurons and associated tissues. Must rapidly process large amount of data: processed by a large percentage of the brain, energy cost (not easy or cheap) Detection of outside world, reality: hallucinogens. Smell and taste: nose and tongue, chemoreceptors. Detection of external chemicals (volatile: can dissolve in air, volatile. The air we ingest is mixed in the sinus and exposes the epithelium to the volatile chemicals. 10^7 sensory cells, bipolar neurons: replaces every 30 days, unique to this sensory. Dendrite ends in cilia, covered with musuc, axon projects to olfactory bulb. Bind to receptor (7-tms-g protein coupled), camp: depolarization. 200 genes for receptors, largets gene family primordial function: extremely important. 1 receptor per neuron, a distribution of sensitivity overlap. 4000 different smells: a signature odor dependent on which neurons are activated, a particular chemical can activate more than one receptor.