Chapter 7: Olfaction (Smell)

Chemical

Olfactory system uses ___ senses. These are theorized to be the first senses developed

10

There are __ million receptor cells involved in olfaction

Odors

Humans can detect ___ if their noses were as close to the ground as dog noses

Odorant

Odor consisting of a volatile substance, most are lipid-soluble and of organic origin

Olfactory Receptors

Contain bipolar neurons, somas in olfactory mucosa, continue to divide throughout one's adult life

Supporting Cells

Contain enzymes to destroy odorant molecules and thus prevent odorants from damaging olfactory receptor cells

10%

Less than ___ _ of air entering our nostrils reach the olfactory epithelium

Mitral Cells

Olfactory receptor axons project to __ __ in olfactory bulb

Glomerulus

Contain mitral cell dendrites and olfactory receptor axon terminals

Same

Each glomerulus receives axon terminals from all olfactory receptor cells that contain the __ protein receptor

Amygdala

Emotional memory and hypothalamus

Piriform Cortex

To hypothalamus and cortex

Entorhinal Cortex

To hippocampus

339

Humans have __ types of olfactory receptors

1 type

Each olfactory receptor has __ __ of receptor molecule on its cilia

Affinities

Odorants bind to receptor cells with different ___

Depolarization

Glomerulus will show ___ like the olfactory receptor cell

Pattern

The ___ of glomeruli activation leads to specific odor detection and coding

Combinations

Different odorant molecules attach to different ___ of receptor molecules

Mask

Some odors can ___the existence of others

Anosmic

Lack of olfaction, risk for Alzheimer's DIsease

Specific anosmia

Specific lack of a single chemical (i.e. sweat)

Neurogenesis

Olfactory system displays consistent ___ in adulthood