Neuroanatomy of the Cranial Nerves Flashcards
Which is the only cranial nerve to exit posteriorly?
CN IV (Trochlear)
What part of the brainstem is the nuclei of origin for CN III?
Superior colliculus (bald headed man)
What part of the brainstem is the nuclei of origin for CN IV?
Inferior colliculus (bald headed man)
Which 4 cranial nerves emerge at the midline of the base of the brain, reflecting the midline location of their nuclei in the brainstem?
III, IV, VI, XII
Which are the mixed cranial nerves?
V, VII, IX, X
What are the 3 sensory nuclei in the brainstem associated with CN V?
Mesencephalic Nucleus - proprioception from chewing but also motor for jaw reflex.
Pontine Trigeminal Nucleus - discriminative touch, vibration)
Spinal Nucleus - pain, temperature
What is unusual about the mesencephalic nucleus?
It is the only site int he CNS where cell bodies of the primary afferent live inside the CNS.
To which nucleus in the thalamus do CN V sensory fibres eventually reach?
Ventral Posteromedial (VPM) Nucleus
What are the 3 nuclei of the facial nerve (CN VII)?
1) Facial Motor Nucleus
2) Superior Salivatory (parasympathetic)
3) Solitary nucleus (sensory - taste)
What are the 4 nuclei of the Glossopharyngeal nerve (IX)?
1 & 2) Solitary Nucleus
3) Inferior Salivatory nucleus (parasympathetic)
4) Nucleus Ambiguous (stylopharyngess muscle)
What are the 4 nuclei of the Vagus (X) nerve?
1 & 2) Solitary nucleus
3) Dorsal Motor Nucleus (parasympathetic)
4) Nucleus Ambiguous (motor)
How is the Solitary Nucleus arranged in the brainstem?
Extends in a V shape from the upper to lower medulla. It supplies taste and general visceral sensation.
Which spinal tract (part of the pyramidal tract) is motor for cranial nerves?
Corticobulbar tract.
What are the ‘pyramidal’ tracts?
The Corticospinal Tract and the Corticobulbar Tract.
What is the reticular formation?
A network of loosely aggregated cells with cell bodies, axons and dendrites intermingling in the central core of the brainstem.
