Flashcards in Autonomics of the Head and Neck Deck (22)
Which cranial nerves does the CRANIAL portion of the parasympathetic system leave the brainstem as?
Within CN III, VII, IX, and X (but vagus doesn't do anything in head)
What are the 4 parasympathetic ganglia within the head, and the parasympathetic fibers of which cranial nerves innervate them?
What are the 3 roots of the ciliary ganglion, and what is connected through those roots?
The sensory root - connects the ganglion to the nasociliary nerve (branch of V1)
Sympathetic root - conveys postganglionic sympathetic fibers from the internal carotid plexus
Parasympathetic root - contains preganglionic parasympathetic fibers from oculomotor nerve and which synapse in the ganglion
From the ciliary ganglion, where do the postganglionic parasympathetic fibers go and where do the postganglionic sympathetic fibers go?
Parasympathetic fibers go to
-sphincter of the pupil
Sympathetic fibers go to
-dilator of the pupil
-vasculature of the eye
Where does the pterygopalatine ganglion receive its preganglionic parasympathetic fibers? What 2 types of nerve fibers make up this particular fiber?
It receives them from the nerve of the pterygoid canal
The nerve of the pterygoid canal is a mix of
-preganglionic parasympathetic fibers and taste fibers from the greater petrosal nerve of the facial nerve
-postganglionic sympathetic fibers from deep petrosal nerve from the internal carotid plexus
Which fibers are joined by the postganglionic parasympathetic fibers of the pterygopalatine ganglion?
-Greater and Lesser palatine nerves
-Posterior nasal branches
-Zygomatic nerve (which ultimately passes them off to lacrimal nerve of V1)
-superior alveolar nerve
What are all the types of fibers that are contained in the greater and lesser palatine branches? What is the origin of each of these branches?
General sensory fibers from the maxillary division of the trigeminal
Parasympathetic fibers from the greater petrosal nerve (from CN VII)
Sympathetic fibers from the deep petrosal nerve (internal carotid plexus)
Taste fibers from the greater petrosal nerve (from CN VII)
What nerve is actually attached to the submandibular ganglion?
lingual nerve of the V3 mandibular division trigeminal
Where do the preganglionic parasymapthetic fibers and taste fibers that travel in the lingual nerve (of V3) originate from? Where do these fibers supply?
The preganglionic parasymapthetic fibers and the taste fibers originate in the chorda tympani of the facial nerve (CN VII)
Supplies the anterior 2/3 of the tongue
Describe the course of the chorda tympani before reaching the submandibular ganglion via the lingual nerve of V3.
Chorda tympani leaves facial nerve in the petrous part of the temporal bone
Traverses the middle ear cavity
Leaves the skull through the petrotympanic fissure
Then synapse in the submandibular ganglion
What are the 3 main structures that postganglionic parasympathetic fibers target after leaving the submandibular ganglion?
The rest join the lingual nerve and proceed to the sublingual and lingual salivary glands
Where is the otic ganglion, and where does it receive its preganglionic fibers through (which nerve)?
It is located medial to the mandibular branch of the trigeminal
Outside of the foramen ovale
Deep in the infratemporal fossa
Receives its fibers from the lesser petrosal nerve
What cranial nerve gives off the lesser petrosal nerve, and what is its course?
Glossopharyngeal nerve (CN IX) gives off the lesser petrosal.
1. Glossopharyngeal gives off the tympanic branch that enters middle ear cavity and contributes to the tympanic plexus
2. Tympanic plexus is the mixture of fibers from the tympanic branch of IX, the internal carotid plexus (sympathetic fibers) and a twig from the facial nerve
3. The parasympathetic fibers from the tympanic plexus leave as the lesser petrosal nerve
4. Lesser petrosal leaves petrous part of temporal and enters middle cranial fossa via hiatus of the lesser petrosal (runs lateral and parallel to the greater petrosal)
5. Lesser petrosal exists the skull through foramen ovale and enters infratemporal fossa
6. Synapses in otic ganglion
7. Postganglionic parasympathetic fibers are then passed to the aucriculotemporal nerve (V3) which distributions them to the parotid gland
Where do the sympathetics that innervate the head and neck originate from? Both the preganglionic and ganglion.
The preganglionic fibers originate from the upper thoracic segments of the spinal cords in the lateral gray horns (interomedial gray columns)
The preganglionic fibers that are destined for the head synapse in the superior cervical ganglion
Along which 2 arteries does the superior cervical ganglion send its fibers?
Along the internal and external carotid arteries (internal and external carotid nerves)
What are the 2 plexi that are given off by the external carotid nerve from the superior cervical ganglion?
The external carotid nerve gives rise to the external carotid plexus as well as a smaller plexus along the common carotid (common carotid plexus)
What are a few examples of areas supplied by the external carotid plexus?
Sweat glands of the face and neck
Any area supplied by the external carotid artery is also supplied by the external carotid plexus and its sympathetic fibers
What is the largest branch from the superior cervical ganglion to the head? What does it form on the internal carotid artery?
Internal carotid nerve is the largest
Forms a plexus on the internal carotid artery known as the internal carotid plexus
What plexus receives some of the fibers from the internal carotid plexus when it is close to the middle ear cavity?
The tympanic plexus on the medial wall of the tympanic cavity
What are the 2 main groups of sympathetic fibers given off by the internal carotid plexus as it travels along with the internal carotid artery? Where do those fibers go?
1. Sympathetic root of the ciliary ganglion
-passes through the ciliary ganglion without synapsing
-These fibers enter short ciliary nerves and are distributed to the dilator of the pupil and to the vasculature of the eye
2. Deep petrosal nerve
-joins with the greater petrosal nerve of CN VII (facial) to form the nerve of the pterygoid canal
-passes through the pterygopalatine ganglion without synapsing and are distributed to all branches of the maxillary division of trigeminal (V2)
What are 4 outcomes of stimulation of sympathetic fibers in the head and neck area?
Dilation of the pupil (mydriasis)
Elevation of the eyelid (smooth muscle component of levator palpebrae superioris)
Vasoconstriction of the blood vessels of the head and neck
Sweating of the skin on face and neck