Cranial nerve Flashcards
Where are primary afferent cell bodies located?
Dorsal root ganglion
Where are the dorsal and ventral roots fused?
Segmental trunk nerves
Form the spinal cord when they fuse - carry all 4 nerve types
What are the 5 nerve types in the ANS?
- Afferent
- Inter-neuron
- pre-ganglionic efferent
- post-ganglionic afferent
- special visceral efferents
How do segmental head nerves differ from segmental trunk nerves?
- Autonomic efferent neurons leave via dorsal root
- Dorsal & Ventral roots do NOT unite - stay as separate nerves
- Presence of special visceral efferents
Which segment has no pharyngeal arch?
segement 1
What are the names of the 2 branches of segment 2, from which cranial nerve do they come from?
Maxillary and Mandibular
Branches of cranial nerve 5
Which segments lose their somites meaning they don’t have a ventral root nerve?
4 and 5
What happens as a result of segment 6 losing its pharyngeal arch?
Doesn’t have a dorsal root nerve
Which segments share their dorsal root nerve?
5 and 7
What neurons do dorsal roots contain (not including exceptions)?
Somatic afferents
Autonomic afferents
Autonomic efferents
Special visceral efferents
What neuron do ventral roots contain?
Somatic efferents
In segment 1, what is the ventral nerve supplying and what is its function?
CN III = occulomotor
- Main role is movement of the eyeball
How does segment 1 have a dorsal root supply despite having no pharyngeal arch?
What is the dorsal supply?
It borrows the dorsal root nerve from segment 2 = Opthalmic branch of V (Trigeminal)
What is the ventral and dorsal root nerve supply of segment 2?
V = IV / Trochlear D = V / Trigeminal
What are the most important components in segment 2 and why?
SA to skin and SVE to muscles for chewing
