H&N 5.1 autonomics

Question 1

What is the arrangement of the parasympathetic nervous system?

Answer 1

preganglionic nerve

ganglion

postganglionic nerve

Question 2

What is a ganglion?

Answer 2

a collection of cell bodies in the peripheral nervous system.

Question 3

What is a nucleus?(nerve-wise)

Answer 3

A collection of cell bodies in the central nervous system.

Question 4

What are the target tissues of the parasympathetic nervous system?

Answer 4

Glands

smooth muscle

Question 5

Where do the sympathetic nerves arise from?

Answer 5

Thoracolumbar spinal cord (T1-L2)

Question 6

Where do the parasympathetic nerves arise from?

Answer 6

The brain stem (and some from the sacral region, those that control micturition)

Question 7

How do sympathetic nerves get to the head and neck?

Answer 7

Via the sympathetic chain of ganglia, of which the superior cervical ganglion supplies the head and neck.

Question 8

How do the sympathetic nerves get to their target tissues in the head and neck?

Answer 8

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.

Question 9

What are the target tissues for the sympathetic nervous system? (Head and neck?)

Answer 9

• 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)

Question 10

What common pathology’s (outside of the autonomic nerves) can lead to damage of the sympathetic nerves?

Answer 10

• carotid artery dissection
• tumours in the apex of the lung (pancoast tumur)

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Question 11

What is the name of the condition which affects the sympathetic innervation to the head and neck?

Answer 11

Horner’s syndrome

Question 12

What are the classical findings in Horner’s syndrome?

Answer 12

• ptosis (partial)
• meiosis (constriction of the pupil)
• anhydrosis (lack of sweating on the affected side of the face)

Question 13

How do parasympathetic fibres get to their target tissues?

Answer 13

Hitch-hike on cranial nerves, then the postganglionic nerves hitchhike on the branches of the trigeminal nerve.

Question 14

What cranial nerves do the parasympathetic nerves hitch-hike?

Answer 14

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)

Question 15

What are the 4 ganglia associated with the parasympathetics of the head and neck?

Which cranial nerves are these associated with?

Answer 15

• cilliary (occulomotor)
• pterygopallatine (greater petrosal nerve)
• submandibular (chorda tympani)
• otic (glossopharyngeal)

Question 16

What is the route of the parasympathetics associated with the cilliary ganlgion?

Answer 16

Travel on the occulomotor nerve

Then postganglionic travel with the opthalmic branch of the trigeminal nerve to innervate the eye

Question 17

What is the function of the parasympathetics associated with the cilliary ganglion?
What are the target tissues?

Answer 17

• eye (sphincter pupillae)

- ciliary body (focus of the lens of the eye)

Question 18

What are the 3 branches of the facial nerve that occur in the petrous part of the temporal bone?

Answer 18

• greater petrosal nerve
• chorda tympani
• stapedius nerve

Question 19

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?

Answer 19

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)

Question 20

What is the route of the parasympathetics associated with the pterygopallatine ganglion?

Answer 20

Preganglionic nerve-greater petrosal nerve

pterygopalatine ganglion

innervation of the lacrimal gland, and mucus membranes of the oral and nasal cavities.

Question 21

What is the route of the parasympathetics associated with the submandibular ganglion?

What are the effector tissues?

Answer 21

preganglionic- chorda tympani nerve

submandibular ganglion

innervation of the submandibular and sublinngual glands.

Question 22

other than a method of travel for autonomics, what is the function of the chorda tympani?

Answer 22

provides anterior 2/3 of the tongue with taste.

Question 23

What is the route of the parasympathetics associated with the otic ganglion?

What are the effector tissues?

Answer 23

preganglionic- travel on glossopharyngeal nerve (particulalry the tympanic nerve)

Otic ganglion

post-ganglionic - mandibular branch of CN V

innervation of the parotid gland

Question 24

What are the functions of the glossopharyngeal nerve?

Answer 24

• 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.

Question 25

What are some of the target tissues of the vagus associated parasympathetics?

Answer 25

• larynx
• laryngeal glands
• oesophagus
• trachea
• thorax
• abdomen

Question 26

What is the name of the nucleus we need to know, and with which ganglion is it associates?

Answer 26

Edinger westphal nuceus, associated with the cilliary ganglion.