autonomic control Flashcards
where do the pre-ganglionic fibres of the sympathetic fibres of the head and neck synapse
sympathetic trunk in the superior cervical ganglion
describe the lengths of the pre and post ganglionic fibres in the sympathetic NS
short pre ganglionic
long post ganglionic
what artery do fibres from the sympathetic NS follow for head and neck innervation
common carotid artery
then either the internal or external
if sympathetic fibres follow the internal carotid artery what effect will this have
will go to the orbit to supply the superior tarsal muscle (causing eye lid retraction) and dilatory pupillae muscle (dilate the pupil)
if sympathetic fibres follow the external carotid artery what effect will this have
control of sweat glands and blood vessels in the head and neck
where in the spinal cord do sympathetic fibres leave
thoracolumbar region (T1-L2)
where in the spinal cord do parasympathetic fibres leave
craniosacral region (brainstem and S2-4)
from what nucleus do pre-ganglionic fibres of the parasympathetic oculomotor nerve leave from
Edinger Westphal nucleus
describe the route of the parasympathetic fibres of the occulomotor nerve
leave the EW nucleus - travel with the occulomotor nerve- synapse at ciliary ganglion - follow trigeminal nerve - innervate lens of eye and sphincter pupillae
what ganglion does the oculomotor nerve synapse at
ciliary ganglion
what ganglion does the glossopharyngeal synapse at
otic nerve
describe the light reflex
the optic nerve is the afferent limb as it detects the light - it then communicates with the EWN on both sides to cause pupil constriction in both eyes via the oculomotor nerve (efferent limb)
what nerves make up the afferent and efferent limbs of the light reflex
afferent = optic efferent = occulomotor
what nerve is affected with a ‘blown pupil’
oculomotor nerve - as this supplies the sphincter pupillae
why does a ‘blown pupil’ occur
increased intercranial pressure compresses the parasympathetic fibres of the oculomotor nerve causing loss to the sphincter pupillae - so you are no longer able to contract the pupil
describe the 2 possible parasympathetic routes of the facial nerve
nucleus - greater petrosal nerve - pterygopalatine ganglion - trigeminal - lacrimal/palatine/nasal glands
nucleus - chorda tympani nerve - submandibular ganglion - trigeminal - submandibular/sublingual glands
what ganglion does the parasympathetics following the greater petrosal nerve synapse at
pterygopalatine ganglion
what ganglion does the parasympathetics following the chorda tympani nerve synapse at
submandibular ganglion
if the parasympathetics follow the greater petrosal nerve what effect will this cause
innervation of the lacrimal, nasal and palatine glands
if the parasympathetics follow the chorda tympani nerve what effect will this have
innervation to submandibular and sublingual glands causing salivation
if there is interruption of the parasympathetics following the facial nerve what effect will this have
get a dry mouth and dry eyes
what is horners syndrome
where a pancoast tumour in the apex of the lungs compresses the superior cervical ganglion giving sympathetic effects
what are the signs and symptoms of horners syndrome
partial ptosis
miosis
anhidrosis
why does horners syndrome only result in partial ptosis not full ptosis
as only the sympathetic innervation to the superior tarsal muscle is lost - the oculomotor nerve still has some motor control of the eye lids
what effects on the autonomic NS does hyperthyroidism have
increases activation of the sympathetic NS
this increases contraction of the superior tarsal muscle causing lid retraction
describe the route of the parasympathetic fibres following the glossopharyngeal nerve
nucleus in brainstem - glossopharyngeal nerve - tympani nerve route - otic ganglion - trigeminal nerve- parotid gland
what 4 cranial nerves carry parasympathetic fibres
occulomotor, facial, glossopharyngeal, vagus
