cranial nerves Flashcards
what are cranial nerves 3-12 part of?
PNS but emerge in the brainste,
where do CNI and II come from?
higher up in the brain - they are extensions of the CNS
what does a cross section of the midbrain resemble?
upside down minnie mouse
what is at the back of the brain stem?
the colliculi
what are the peduncles?
they are white matter tracts made of motor fibres
what is the cerebral aqueduct contained in?
the central canal
what is a nucleus in the CNS?
a collection of cell bodies
what is the correlation of fibres and nuclei?
for each type of fibre within a cranial nerve there is a corresponding nucleus in the brain stem
how many nuclei does CNIII have and why?
CNIII carries somatic motor fibres for the extraoccular muscles which come from the extraocular nucleus. It also carries visceral autonomic control for the intraocular muscles which are the sphincter pupillae and the ciliary muscles and these come from the Edinger-Westphal nucleus
where does CNII exit from?
the interpeduncular fossa
what happens with injury to CNIII?
can injure both or just one function
where does the olfactory tract/ bulb come from?
the telencephalon
where are cranial nuclei found?
the are found spanning the length of the brainstem - there are many nuclei different fibre types that are in the medulla or midbrain.
where are sensory and motor nuclei found?
sensory more laterally and motor more medially within the brainstem - in tegmentum
what can be seen in the rostral medulla?
the fourth ventricle
for the head and neck what is found medially and laterally?
parasympathetic, motor and somatic motor are found medially and sensory laterally . They either carry sensory afferent or motor efferent fibres
what comprises somatic motor?
touch and temperature
what comprises special sensory?
smell, taste, hearing balance
what does visceral mean?
maintaining and monitoring the internal state of an organ
where are the cranial nuclei in relation to the ventricular system?
they are anterior to the ventricular system