Olfaction

It must be volatile (able to float through air) and small (less than 5.8 E-22)

to filter, warm, and humdifiy the air we breathe.

• Supporting cells- provides metabolic and phyiscal support for the OSNs.
• Basal cells- precursor cells
• Olfactory sensory neurons- main cell type, contain cilia on its dendrites that have receptor cites for odorant molecules.

bony structure at the level of the eybrows between the nose and the brain. It has tiny holes that pass the axons on the ends of the OSNs.

smell blindness; Usually it is caused by upper respiratory tract infection or snionasal disease. Can also be caused by head trauma, or different medications. Usually it is not congenital.

Olfactory (I) and Trigeminal (V). Olfactory is actually smell, while trigeminal is the feeling that goes along with some smells.

• Shape-pattern theory- odorants activate an array of olfactory receptors in the olfactory epithelia, producing specific firing patterns which determine the scent
• Vibration theory-every perceived smell has a different vibrational frequency. molecules that produce the same frequencies smell the same. The problem with this theory is that it does not explain specific anosmias and different scents produced by stereoisomers.

in the right hemisphere of the brain.

receptor adaptation is when the receptors stop responding to the odorant because of continuous exposure causing detection of the odorant to stop. Cross adaptation is when the detection of an odorant is reduced after being exposed to another one.