Olfactory Nerve Flashcards
What kind of nerve is the Olfactory Nerve?
SSA - Special Sensory Afferent
Where does Olfaction begin?
Olfactory Epithelium
Where is the Olfactory Epithelium located?
Roof of the nasal cavity, and extends into the superior nasal conchae and nasal septum
What allows scent molecules to by captured and dissolved?
Nasal mucosa keeping the area moist
What do olfactory epithelia have in the mucosal layer?
Small ciliary processes
What do ciliary r/c transmit?
Sensory input into the bipolar olfactory epithelium
Where does sensory information transmit after the bipolar olfactory epithelium?
Though the cribriform plate into the olfactory bulb
When does olfactory transduction begin?
Olfactant binding to r/c on ciliary processes
What happens when olfactant binds to ciliary processes?
G-protein activation results in inc in intracellular cAMP, creating graded r/c potential
What allows for discrimination of up to 10,000 different smells?
Variations in r/c protein coupled with CNS integration.
What is the olfactory bulb?
A 5 layered area at the rostral enlargement of the olfactory tract
How are the olfactory tracts related to embryonic development?
The olfactory tracts are telencephalic outpouchings
What does the olfactory area house?
second order neurons
Where do nerve fibers project?
From the mucosal layer to the 2nd layer of the bulb
What is the 2nd layer of the olfactory bulb called?
The Glomerular layer
What are Glomerular neurons?
Interneurons between the ascending neuroepithelial nerve fibers from layer 1 and the descending fibers from the mitral cells in layer 4
What do Glomerular neurons also integrate with?
Tufted cells from layer 3.
What is the 3rd layer of the olfactory bulb called?
External Plexiform Layer
What interneuron cell group is in the 5th layer of the olfactory bulb?
Granular cells
Describe the 5 layers of the Olfactory Bulb
- Nerve Fiber Layer
- Glomerular Layer
- Tufted Cell Layer
- Mitral Cell Layer
- Granule Cell Layer
What composes the olfactory tract?
The projections of the mitral and tufted cell layers
What does the olfactory tract divide into?
Medial and Lateral Olfactory Stria
Where is the division of the olfactory tract?
In the olfactory trigone, anterior to the perforated substance
Which division carries the majority of olfactory information.
Lateral Stria
Where does the Lateral Stria take information to?
Lateral Primary Olfactory Area
What does the olfactory area consist of?
Uncut
Entorhinal area
Insula
Amygdaloid Body
Where does the medial olfactory stria project to?
Medial olfactory area
Where is the medial olfactory area located?
Medial surface of the frontal lobe
What functional system is the medial surface of the frontal closely associated with?
Limbic System
What is the Primary Olfactory Cx also known as?
Piriform and Periamygdaloid Cx
