1: Unit II CN I Flashcards
What type of neurons are olfactory neurons?
Bipolar sensory
Where are olfactory neurons found?
In olfactory epithelium lining the superior part of the nasal cavity
What covers the olfactory epithelium?
A thin layer of mucus
How are olfactory neurons supported?
Via “supporting cells”
Olfactory hairs function as receptors
How do olfactory central processes (axons) work?
Collect 10-20 olfactory nerves, convey info to olfactory bulbs
Are olfactory neurons myelinated or unmyelinated?
Unmyelinated
What are olfactory neurons covered in?
Schwann cells
Where do olfactory neurons pass?
Through crib reform plate (ethmoid bone)
As olfactory neurons enter the olfactory bulb, what do they synapse on?
Dendrites of mitral cells
What are formed at the synapses between olfactory neurons and mitral cells?
Synaptic glomeruli
What is another name for olfactory nerves?
Fila olfactoria
What are mitral cells considered?
Secondary sensory neurons
Where are mitral cell bodies located?
Olfactory bulb
Where do mitral cells relay information to?
Posterior to the olfactory tract
Where do the olfactory tract fibers split into medial and lateral olfactory striae?
Anterior perforated substance
How do medial stria fibers travel?
Cross midline in anterior commissure and travel to the opposite olfactory bulb
Where do lateral stria fibers carry info to?
Primary olfactory cortex: periamygdaloid and prepiriform area, including uncus (BMA 34) on medial aspect of temporal lobe
Sencondary: enterohinal area BMA 28
What are 2 major points about how the olfactory neurons function?
1: crossing ensures that the olfactory cortex on each side from both bulbs
2: smell is not segregated
Describe the olfactory pathway:
2 neurons receptor to cortex
Thalamus NOT in pathway
What is a anosmia?
In ability to smell (born that way or skull fracture)
Test both nostrils
What can CSF leakage mimick
A cold w/o symptoms
Thinner than snot and HALO sign
What is the terminal nerve?
In nasal septum, autonomic function
What are the primary sensory neurons of CN I (olfactory) called?
Olfactory neurons
