Flashcards in Chemical Senses - von Bartheld Deck (78)
Are olfactory nerve fibers myelinated?
Facial fractures can shear the olfactory nerves causing what?
Loss of smell
Is the olfactory nerve long or short?
Short; they are the actual sensory cells that pierce the cribiform plate that then synapse at the olfactory bulb
Is the olfactory tract long or short?
Long; olfactory tract goes back from the olfactory bulb to the cortex
In head trauma, what chemical difference between CSF and snot would help you differentiate between a CSF leak and a runny nose?
CSF has a high glucose concentration
Are olfactory cilia motile?
What is the main function of nasal mucus?
what protein does mucus contain that protects against bacteria?
Basal cells in the nasal mucosa have what function?
They are stem cells that regenerate the receptor cells
what is the lifespan of a receptor cell?
Does each receptor cell have its own axon? How does this impact receptor cell turnover?
Yes; axons must also be regenerated and sent back up through the cribiform plate to synapse at the olfactory bulb
Bowman's glands produce what substance?
Nasal supporting cells (sustentacular cells) have what function? What neural cell type are they analagous to?
They provide metabolic and physical support for the receptor cells. They are analgous to glial cells
Where are the odorant receptors located on the receptor cells?
On the cilia only, NOT on the body!
What percent of all mammalian genes are devoted to odorant receptors?
is the amino acid sequence of odorant receptors highly conserved?
No, it is highly variable to allow bidning of multiple odorants to a single receptor
odorant molecules receptors are ion channles or GPCRs?
Activation of odorant GPCRs opens what ion chanel?
Does each receptor cell have all odorant receptors?
No, a receptor cell has only 1-3 receptor types
A combination of (blank) number of receptor subunits makes all of the receptors for all odorants
Olfactory glomeruli are made of what types of cells?
The apical dendrites of (blank) cells are also in the olfactory glomeruli
One glomerulus is specialized for how many odors?
External plexiform layer of the olfactory bulb contains what? (3)
1. lateral dendrites of mitral cells
2. cell bodies and lateral dendrites of tufted cells
3. dendrites of granule cells
the granule layer of the olfactory bulb contains what? (1)
cell bodies of granule cells
What are the interneurons of the olfactory bulb? What cell types do they connect?
Periglomerular cells; they connect mitral cells at the receptor-mitral junction
Where do granule cells connect mitral cells?
Near the cell body
Olfactory (blank) form the glomeruli in the bulb
Glomeruli are the sites where filae synapse on dendrites from (blank) cells and tufted cells