H&N 5.1 autonomics Flashcards
What is the arrangement of the parasympathetic nervous system?
preganglionic nerve
ganglion
postganglionic nerve
What is a ganglion?
a collection of cell bodies in the peripheral nervous system.
What is a nucleus?(nerve-wise)
A collection of cell bodies in the central nervous system.
What are the target tissues of the parasympathetic nervous system?
Glands
smooth muscle
Where do the sympathetic nerves arise from?
Thoracolumbar spinal cord (T1-L2)
Where do the parasympathetic nerves arise from?
The brain stem (and some from the sacral region, those that control micturition)
How do sympathetic nerves get to the head and neck?
Via the sympathetic chain of ganglia, of which the superior cervical ganglion supplies the head and neck.
How do the sympathetic nerves get to their target tissues in the head and neck?
By hitchhiking on the blood vessels, mainly the internal carotid artery.
When closer to the tissues they hitchike on cranial nerve III (occulomotor nerve) to get to the effector tissue.
What are the target tissues for the sympathetic nervous system? (Head and neck?)
- tarsal muscle (open eyes wide)
- dilator pupillae muscle (dilate pupil, let more light in and be more aware)
- sweat glands
- smooth muscle of errector pilli muscle to make hairs stand on end.
- lacrimal and salivary glands (lesser role, they reduce stimulation)
What common pathology’s (outside of the autonomic nerves) can lead to damage of the sympathetic nerves?
- carotid artery dissection
- tumours in the apex of the lung (pancoast tumur)
-
What is the name of the condition which affects the sympathetic innervation to the head and neck?
Horner’s syndrome
What are the classical findings in Horner’s syndrome?
- ptosis (partial)
- meiosis (constriction of the pupil)
- anhydrosis (lack of sweating on the affected side of the face)
How do parasympathetic fibres get to their target tissues?
Hitch-hike on cranial nerves, then the postganglionic nerves hitchhike on the branches of the trigeminal nerve.
What cranial nerves do the parasympathetic nerves hitch-hike?
occulomotor (CN iii)
facial (chorda tympani and greater petrosal nerves) (CN VII)
glossopharyngeal (CN IX)
vagus (CN X)
(post-ganglionic travel via the branches of the trigeminal nerve- CN V)
What are the 4 ganglia associated with the parasympathetics of the head and neck?
Which cranial nerves are these associated with?
- cilliary (occulomotor)
- pterygopallatine (greater petrosal nerve)
- submandibular (chorda tympani)
- otic (glossopharyngeal)
What is the route of the parasympathetics associated with the cilliary ganlgion?
Travel on the occulomotor nerve
Then postganglionic travel with the opthalmic branch of the trigeminal nerve to innervate the eye
What is the function of the parasympathetics associated with the cilliary ganglion?
What are the target tissues?
- eye (sphincter pupillae)
- ciliary body (focus of the lens of the eye)
What are the 3 branches of the facial nerve that occur in the petrous part of the temporal bone?
- greater petrosal nerve
- chorda tympani
- stapedius nerve
What is the name of the sensory ganglion associated with the branches of the facial nerve in the petrosal part of the temporal bone?
What’s the significance of the geniculate ganglion with regards to damage to the facial nerve?
the geniculate ganglion.
A lesion before it will affect all the branches of the facial nerve carrying parasympathetic fibres.
A lesion after it will spare the greater petrosal branch, so lacrimation will still be seen (and innervation of nasal/oral mucus membranes)
What is the route of the parasympathetics associated with the pterygopallatine ganglion?
Preganglionic nerve-greater petrosal nerve
pterygopalatine ganglion
innervation of the lacrimal gland, and mucus membranes of the oral and nasal cavities.
What is the route of the parasympathetics associated with the submandibular ganglion?
What are the effector tissues?
preganglionic- chorda tympani nerve
submandibular ganglion
innervation of the submandibular and sublinngual glands.
other than a method of travel for autonomics, what is the function of the chorda tympani?
provides anterior 2/3 of the tongue with taste.
What is the route of the parasympathetics associated with the otic ganglion?
What are the effector tissues?
preganglionic- travel on glossopharyngeal nerve (particulalry the tympanic nerve)
Otic ganglion
post-ganglionic - mandibular branch of CN V
innervation of the parotid gland
What are the functions of the glossopharyngeal nerve?
- motor innervation of the stylopharyngeus
- sensory to the oropharynx and tonsils
- taste and general sensation to the posterior 1/3 of hte tongue.
- sensory to the carotid body/sinus.
What are some of the target tissues of the vagus associated parasympathetics?
- larynx
- laryngeal glands
- oesophagus
- trachea
- thorax
- abdomen
What is the name of the nucleus we need to know, and with which ganglion is it associates?
Edinger westphal nuceus, associated with the cilliary ganglion.