Parasympathetic innervation: ciliary ganglion Flashcards
what is the parasympathetic innervation a division of?
autonomic nervous system
function of parasympathetic NS?
involuntary, and acts with the sympathetic system to maintain body homeostasis
action of PNS?
‘rest and digest’ response
where do parasympathetic fibres begin?
in the central nervous system
where are the nerves supplying the head and neck situated?
within four nuclei, located within the brainstem
what is each nucleus of the parasympathetic fibres associated with?
a cranial nerve
what are the cranial nerves associated with the nucleus of parasympathetic fibres?
the oculomotor, facial, glossopharyngeal and vagus nerves
function of the cranial nerves associated with the nucleus of parasympathetic fibres?
these nerves carry the parasympathetic fibres out of the brain
After leaving the brain, the parasympathetic fibres from each nuclei synapse where?
in a peripheral ganglion
what is the peripheral ganglion?
a collection of neurone cell bodies outside the CNS
where are the peripheral ganglion typically located?
near to the target viscera
From the ganglia, post-ganglionic parasympathetic fibres continue to?
to the organs in the head and neck, providing parasympathetic innervation
what are the parasympathetic ganglion located within the head?
there are 4:
ciliary, otic, pterygopalatine and submandibular
where do the 4 parasympathetic ganglion receive fibres from?
from the oculomotor, facial and glossopharyngeal nerves
what does the vagus nerve innervate?
only innervates structures in the thorax and abdomen
what are most ganglia associated with?
with some sensory and sympathetic nerves – these do not synapse in the ganglia, they merely travel through it
where is the ciliary ganglion located?
within the bony orbit
situated anteriorly to the superior orbital fissure, between the lateral rectus muscle and the optic nerve
pre-ganglionic fibres of the ciliary ganglion?
The ciliary ganglion is supplied by fibres from the Edinger-Westphal nucleus (associated with the oculomotor nerve)
Post-ganglionic fibres of the ciliary ganglion: where do parasympathetic fibres leave the ganglion?
leave the ganglion via the short ciliary nerves
where do parasympathetic fibres continue from the ciliary ganglion?
continue into the orbit to innervate structures of the eye
Target organs of the post-ganglionic fibres from ciliary ganglion?
innervate the sphincter pupillae (contracts the pupil) and the ciliary muscles (accommodates for near vision)
what else is there in the post-ganglionic fibres of ciliary gnaglion?
two sets of nerve fibres pass through the ciliary ganglion without synapsing
what are the two sets of nerve fibres pass through the ciliary ganglion without synapsing?
Sympathetic nerves from the internal carotid plexus
Sensory fibres from the nasociliary nerve
what does Sympathetic nerves from the internal carotid plexus innervate?
innervate the dilator pupillae muscle
what are Sensory fibres from the nasociliary nerve a branch of?
a branch of the ophthalmic division of the trigeminal nerve
what does Sensory fibres from the nasociliary nerve innervate?
innervate the cornea, ciliary body and iris
