autonomic control

Question 1

where do the pre-ganglionic fibres of the sympathetic fibres of the head and neck synapse

Answer 1

sympathetic trunk in the superior cervical ganglion

Question 2

describe the lengths of the pre and post ganglionic fibres in the sympathetic NS

Answer 2

short pre ganglionic

long post ganglionic

Question 3

what artery do fibres from the sympathetic NS follow for head and neck innervation

Answer 3

common carotid artery

then either the internal or external

Question 4

if sympathetic fibres follow the internal carotid artery what effect will this have

Answer 4

will go to the orbit to supply the superior tarsal muscle (causing eye lid retraction) and dilatory pupillae muscle (dilate the pupil)

Question 5

if sympathetic fibres follow the external carotid artery what effect will this have

Answer 5

control of sweat glands and blood vessels in the head and neck

Question 6

where in the spinal cord do sympathetic fibres leave

Answer 6

thoracolumbar region (T1-L2)

Question 7

where in the spinal cord do parasympathetic fibres leave

Answer 7

craniosacral region (brainstem and S2-4)

Question 8

from what nucleus do pre-ganglionic fibres of the parasympathetic oculomotor nerve leave from

Answer 8

Edinger Westphal nucleus

Question 9

describe the route of the parasympathetic fibres of the occulomotor nerve

Answer 9

leave the EW nucleus - travel with the occulomotor nerve- synapse at ciliary ganglion - follow trigeminal nerve - innervate lens of eye and sphincter pupillae

Question 10

what ganglion does the oculomotor nerve synapse at

Answer 10

ciliary ganglion

Question 11

what ganglion does the glossopharyngeal synapse at

Answer 11

otic nerve

Question 12

describe the light reflex

Answer 12

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)

Question 13

what nerves make up the afferent and efferent limbs of the light reflex

Answer 13

afferent = optic 
efferent = occulomotor

Question 14

what nerve is affected with a ‘blown pupil’

Answer 14

oculomotor nerve - as this supplies the sphincter pupillae

Question 15

why does a ‘blown pupil’ occur

Answer 15

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

Question 16

describe the 2 possible parasympathetic routes of the facial nerve

Answer 16

nucleus - greater petrosal nerve - pterygopalatine ganglion - trigeminal - lacrimal/palatine/nasal glands

nucleus - chorda tympani nerve - submandibular ganglion - trigeminal - submandibular/sublingual glands

Question 17

what ganglion does the parasympathetics following the greater petrosal nerve synapse at

Answer 17

pterygopalatine ganglion

Question 18

what ganglion does the parasympathetics following the chorda tympani nerve synapse at

Answer 18

submandibular ganglion

Question 19

if the parasympathetics follow the greater petrosal nerve what effect will this cause

Answer 19

innervation of the lacrimal, nasal and palatine glands

Question 20

if the parasympathetics follow the chorda tympani nerve what effect will this have

Answer 20

innervation to submandibular and sublingual glands causing salivation

Question 21

if there is interruption of the parasympathetics following the facial nerve what effect will this have

Answer 21

get a dry mouth and dry eyes

Question 22

what is horners syndrome

Answer 22

where a pancoast tumour in the apex of the lungs compresses the superior cervical ganglion giving sympathetic effects

Question 23

what are the signs and symptoms of horners syndrome

Answer 23

partial ptosis
miosis
anhidrosis

Question 24

why does horners syndrome only result in partial ptosis not full ptosis

Answer 24

as only the sympathetic innervation to the superior tarsal muscle is lost - the oculomotor nerve still has some motor control of the eye lids

Question 25

what effects on the autonomic NS does hyperthyroidism have

Answer 25

increases activation of the sympathetic NS

this increases contraction of the superior tarsal muscle causing lid retraction

Question 26

describe the route of the parasympathetic fibres following the glossopharyngeal nerve

Answer 26

nucleus in brainstem - glossopharyngeal nerve - tympani nerve route - otic ganglion - trigeminal nerve- parotid gland

Question 27

what 4 cranial nerves carry parasympathetic fibres

Answer 27

occulomotor, facial, glossopharyngeal, vagus