Parasympathetics of head and neck Flashcards
What structures in the head and neck are innervated by the parasympathetic nervous system?
Sphincter pupillae muscle
Ciliary muscle
Lacrimal glands
Salivary and mucosal glands
What type of muscle is the sphincter pupillae muscle made up of?
Smooth muscle
What is the action of the sphincter pupillae muscle?
Constricts the pupil
What type of muscle is the ciliary muscle made up of?
Smooth muscle
What is the action of the ciliary muscle?
Changes the thickness of the length for focussing
How many parasympathetic nuclei are there in the brainstem for head and neck structures?
Four
What effect does parasympathetic innervation have on the lacrimal, salivary and mucosal glands?
Increases secretions
What is the parasympathetic nucleus in the brainstem that gives off nerve fibres innervating smooth muscle in the eye?
Edinger Westphal nucleus
Where do the parasympathetic pre-ganglionic nerve fibres synapse with the parasympathetic post-ganglionic nerve fibres?
At parasympathetic ganglia
How many parasympathetic ganglia are there?
Four
What are the parasympathetic ganglia in the head and neck?
Ciliary
Submandibular
Pterygopalatine
Otic
Where is the ciliary ganglion located?
Orbit
Where is the submandibular ganglion located?
Below the mandible
Where is the pterygopalatine ganglion located?
In the pterygopalatine fossa
How do parasympathetic pre-ganglionic nerve fibres reach the parasympathetic ganglia?
Run with CNs 3, 7, 9, 10
What cranial nerve do parasympathetic pre-ganglionic nerve fibres innervating muscles in the eye run with?
CN3 oculomotor nerve
How do parasympathetic post-ganglionic nerve fibres reach the head and neck structures they innervate?
Run with branches of the CN5 trigeminal nerve
What branch of the CN5 trigeminal nerve do the parasympathetic post-ganglionic nerve fibres supplying muscles in the eye run with?
Branches of the opthalamic branch
What cranial nerve do parasympathetic pre-ganglionic nerve fibres innervating the lacrimal, sublingual and submandibular salivary glands and mucosal glands run with?
CN7 facial nerve and its branches
- greater petrosal nerve
- chorda tympani nerve
When does the greater petrosal nerve branch off the facial nerve?
After passing through the internal auditory meatus
inside the petrous bone
at the geniculate ganglion
What ganglion do parasympathetic pre-ganglionic nerve fibres running with the greater petrosal nerve synapse at?
Pterygopalatine ganglion
What glands do parasympathetic post-ganglionic fibres arising from the pterygopalatine ganglion synapse innervate?
Lacrimal glands
Mucosal glands
- nasal
- palatine
Where does the chorda tympani nerve branch off the facial nerve?
After passing through the internal auditory meatus
inside the petrous bone
in the middle ear
What is the function of the chorda tympani nerve, apart from the parasympathetic pre-ganglionic nerve fibres it carries?
Special sensory - taste from anterior 2/3 of tongue
What ganglion do parasympathetic pre-ganglionic nerve fibres running with the chorda tympani nerve synapse at?
Submandibular ganglion
What glands do parasympathetic post-ganglionic nerve fibres arising from the submandibular ganglion synapse innervate?
Salivary glands
- submandibular
- sublingual
Which cranial nerve do the parasympathetic pre-ganglionic nerve fibres innervating the parotid gland run with?
CN9 glossopharyngeal nerve branch
-tympanic nerve and lesser petrosal nerve
When does the tympanic nerve branch off the CN9 glossopharyngeal nerve?
After the CN9 glossopharyngeal nerve has passed through the jugular foramen
What is the route of the tympanic nerve?
Ascends up and passes into petrous part of temporal nerve
forms tympanic plexus in the petrous bone
exits petrous part of temporal bone
What is the contination of the tympanic nerve?
Lesser petrosal nerve
When does the tympanic nerve become the lesser petrosal nerve?
When the tympanic nerve exits the petrous part of the temporal bone
What is the route of the lesser petrosal nerve?
Passes through foramen ovale
down to otic ganglion
Where is the otic ganglion located?
Below the foramen ovale
in the infratemporal fossa
What branch of the CN5 trigeminal nerve do parasympathetic post-ganglionic fibres arising from the otic ganglion run with?
Branches of the mandibular branch
What structures in the neck, thorax and abdomen are innervated by the parasympathetic nervous system?
Heart
Glands and smooth muscle of resp. tract, GI tract
What cranial nerve do parasympathetic pre-ganglionic nerve fibres innervating structures in the neck, thorax and abdomen run with?
CN10 vagus nerve
Where do parasympathetic pre-ganglionic nerve fibres running with the vagus nerve synapse with the parasympathetic post-ganglionic nerve fibres?
At the target tissues or in the target tissues
What is the pupillary light reflex?
Shining light in someone’s pupil
makes their pupils constrict
Which of the pupils constrict when light is shone into one pupil?
Both pupils constrict
What is it called when the pupil that has light shone into it constricts?
Direct reflex
What is it called when light is shone into one pupil, and the other pupil constricts?
Consensual reflex
How does the pupillary light reflex work?
Sensory information carried from the retina by the CN2 optic nerve on same side
gives off branches to both right and left Edinger Westphal nuclei
Motor information carried by parasympathetic nerve fibres to sphincter pupillae muscle on both sides
sphincter pupillae muscles contract and constrict the pupils
