SM_20b: Autonomic Innervation of the Head and Neck Flashcards
In general, sympathetics are distributed to ____, while parasympathetics are restricted to ____, ____, and ____
In general, sympathetics are distributed to all vascularized portions of the body and sweat glands, while parasympathetics are restricted to head, neck, and body cavities
(glandular secretion, except for sweat glands, is parasympathetically mediated)
Sympathetic fibers go to ____ and ____ in the eye
Sympathetic fibers go to dilator pupillae (opening pupil) and superior tarsal (raising eyelid) muscles in the eye
(sympathetic fibers go to vascular smooth muscle, sweat glands, and arrector pili muscles)
Parasympathetic secretomotor neurons innervate ____ in the head, three pairs of large ____, the ____, and the ____ and ____ smooth muscles
Parasympathetic secretomotor neurons innervate mucosal glands in the head, three pairs of large salivary glands, the lacrimal gland, and the sphincter pupillae and ciliary muscle smooth muscles
Target organs in the head and neck are responsible for ____, ____, and ____
Target organs in the head and neck are responsible for mucus flow, salivating, and crying
Sympathetics ___ the pupil and ___ the eyelid, while parasympathetics ___ the pupil and ___ the lens
Sympathetics dilate the pupil (dilator pupillae) and raise the eyelid (superior tarsal muscle), while parasympathetics close down the pupil (sphincter pupillae) and accomodate the lens (ciliary muscle)
In salivary and lacrimal glands, sympathetics produce more ____ secretions, while parasympathetics produce more ____ secretions
In salivary and lacrimal glands, sympathetics produce more viscous secretions, while parasympathetics produce more water secretions
In mucosal glands, sympathetics produce more ____ mucus, while parasympathetics produce more ____ mucus
In mucosal glands, sympathetics produce more fluid mucus, while parasympathetics produce more viscous mucus
Describe the three organizing principles of autonomic innervation to the head and neck
Three organizing principles of autonomic innervation to the head and neck
- Sympathetics in the head are postganglionic, traveling with branches of the carotid arteries
- Parasympathetic preganglionics leave the brain with CN III, VII, IX, and X and synapse in the ciliary (CN III), otic (CN IX), pterygopalatine (CN VII), and submandibular ganglia (CN VII) associated with trigeminal nerve branches
- Postganglionic parasympathetics are delivered to target organs by hitchhiking on sensory branches of CN V
All sympathetics in the head are ____, traveling with branches of the ____ and ____ arteries
All sympathetics in the head are postganglionic, traveling with branches of the carotid (internal and external) and vertebral arteries
(preganglionic fibers synapse in the superior cervical ganglion)
Postganglionic sympathetics regulate ____, ____, ____, and ____
Postganglionic sympathetics regulate blood flow (facial vessels), sweating, eyelid elevation (via superior tarsal muscle), and pupil dilation (via dilator pupillae muscle)
Horner’s syndrome is interruption of the ____ due to a compression lesion of the ____
Horner’s syndrome is interruption of the postganglionic sympathetics due to a compression lesion of the sympathetic trunk
(at T1 outflow level due to a lung tumor in the mediastinum here)
Parasympathetic preganglionics leave the brain with CNs ___, ___, ___, and ___ and synapse in four ganglia: ___, ___, ___, and ___ associated with trigeminal nerve branches
Parasympathetic preganglionics leave the brain with CNs III, VII, IX, and X and synapse in four ganglia: ciliary (CN III), otic (CN IX), pterygopalatine (CN VII), and submandibular (CN VII) associated with trigeminal nerve branches
COPS-3977: Ciliary 3, otic 9, pterygopalatine 7, submandibular 7
Parasympathetic preganglionics synapse in four ganglia associated with ____ nerve branches
Parasympathetic preganglionics synapse in four ganglia associated with trigeminal nerve branches
Trigeminal nerve is mostly ____ but includes ____ and ____
Trigeminal nerve is mostly general sensory but includes parasympathetic ganglia and target organs
(hitchhiking / overlay principle regarding parasympathetics and CN V branches: trigeminal network remains if you take away the autonomic fibers)
Describe the ciliary ganglion
Ciliary ganglion
- Preganglionic parasympathetics fibers leave brain in CN III -> enter ciliary ganglion -> synapse
- Postganglionic fibers delivered to target organs with nasociliary (part of V1) branches known as short ciliary nerves (also contain sympathetics)
- Targets: sphincter pupillae, cilary muscle
- Lacrimal gland does NOT receive its parasympathetic innervation from CN III
Parasympathetics supply two smooth muscles in eyeball: ____ and ____
Parasympathetics supply two smooth muscles in eyeball: sphincter pupillae and ciliary muscle
Describe the otic ganglion
Otic ganglion
- Presynaptic parasympathetic fibers leave brain in CN IX -> exit jugular foramen -> tympanic branch re-enters skull and contributes to tympanic plexus in middle ear cavity -> fibers leave via lesser petrosal nerve -> out foramen ovale -> synapse in otic ganglion
- Postganglionic fibers delivered to target organ (parotid gland) with auriculotemporal nerve (V3)
- These secretomotor fibers regulate secretion of the parotid salivary gland
_____ branch of the mandibular division of the trigeminal nerve (V3) splits around the middle meningeal artery, delivering postganglionic fibers to the _____
Auriculotemporal nerve branch of the mandibular division of the trigeminal nerve (V3) splits around the middle meningeal artery, delivering postganglionic fibers to the parotid gland
Frey’s syndrome / gustatory sweating is ____ after ____
Frey’s syndrome / gustatory sweating is when sweat glands become activated and cheek becomes flushed and wet when salivation is stimulated after damaged postganglionic parasympathetic secretomotor fibers to parotid tissues undergo abnormal regeneration and incorrectly resupply the sympathetic innervated sweat glands and vessels of overlying skin
Parasympathetics and sympathetics supply ____ target structures in the same general region
Parasympathetics and sympathetics supply different target structures in the same general region
(conflation of typically distinct functions / targets due to atypical nerve regeneration / connections and the unique use of ACh for both neurons in sweat glands)
Describe the pterygopalatine ganglion
Pterygopalatine ganglion
- Preganglionic parasympathetic fibers leave brain in CN VII -> leave via greater petrosal nerve -> courses across foraemn lacerum -> joins deep petrosal sympathetic nerve and enters pterygoid canal -> goes into pterygopalatine fossa to synapse in ganglion
- Postganglionic fibers are distributed to target organs in midface and orbit: nasal mucosal glands via V2 branches, lacrimal gland via zygomatic (V2) to lacrimal (V1) nerves
- Secretomotor fibers regulate secretion of mucus and tears from the mucosal and lacrimal glands
_____ joins with the _____ to form the nerve of the pterygoid canal
Sympathetic deep petrosal nerve joins with the parasympathetic greater petrosal nerve to form the nerve of the pterygoid canal
Describe the bony pathway for the greater petrosal route
Bony pathway for the greater petrosal route
- Internal acoustic meatus
- Groove for greater petrosal
- Goes across foramen lacerum
- To enter pterygoid canal
Pterygoid canal traverses the sphenoid at ____ from the ____ to ____
Pterygoid canal traverses the sphenoid at the base of the pterygoid plates from the foramen lacerum to the pterygopalatine fossa
(foramen rotundum runs parallel and above)
Facial nerve (VII) branches in the ____
Facial nerve (VII) branches in the petrous temporal bone
Describe the submandibular ganglion
Submandibular ganglion
- Presynaptic parasympathetic fibers leave brain in CN VII -> fibers leave via chorda tympani -> courses through infratemporal fossa and joins lingual nerve -> fibers synapse in submandibular ganglion
- Postganglionic parasympathetic fibers re-enter the lingual nerve (V3 branch to be distributed to the submandibular and sublingual glands
- These secretomotor fibers regulate secretion of the saliva from submandibular and sublingual and small salivary glands and mucous glands
Parasympathetics to the submandibular / sublingual salivary glands include ____, ____, and ____
Parasympathetics to the submandibular / sublingual salivary glands include chorda tympani, lingual nerve, and submandibular ganglion
Three branches of the facial nerve (CN VII) are ____, ____, and ____
Three branches of the facial nerve (CN VII) are greater petrosal, chorda tympani, and facial nerve proper
- Greater petrosal: joins deep petrosal to form nerve of the pterygoid canal
- Chorda tympani: joins lingual nerve
- Facial nerve proper: exits stylomastoid foramen
Describe the parasympathetic pathway of oculomotor nerve (III)
Parasympathetic pathway of oculomotor nerve (III)
- Oculomotor nerve (III)
- Ciliary ganglion
- Short ciliary nerves (V1 branches)
- Sphincter pupillae and ciliary muscle
Describe the parasympathetic pathway of glossopharyngeal nerve (IX)
Parasympathetic pathway of glossopharyngeal nerve (IX)
- Glossopharyngeal nerve (IX)
- Tympanic nerve, tympanic plexus
- Lesser petrosal nerve
- Otic ganglion
- Auriculotemporal nerve (V3 branch)
- Parotid gland
Describe the parasympathetic pathway of facial nerve (VII)
Parasympathetic pathway of facial nerve (VII)
- Facial nerve (VII)
- Greater petrosal nerve
- Nerve of pterygoid canal
- Pterygopalatine ganglion
- Maxillary nerve (V2 branches)
- Nasal, palatal mucous glands and lacrimal gland
Describe the parasympathetic pathway of facial nerve (VII)
Parasympathetic pathway of facial nerve (VII)
- Facial nerve (VII)
- Chorda tympani
- Lingual nerve (V3 branch)
- Submandibular ganglion
- Lingual nerve
- Submandibular and sublingual glands
