ANS of head and neck

Question 1

Where does the autonomic nervous system originate from?

Answer 1

the peripheral nervous system

Question 2

Where is the central control of ANS?

Answer 2

the hypothalamus

Question 3

What does the ANS affect?

Answer 3

internal organs and glands

• body functions that are not under conscious control (smooth muscle in viscera)
• eye, salivary and lacrimal glands

Question 4

What is the main overall role of the ANS?

Answer 4

maintaining and regulating the body internal enviornment

Question 5

What is the main functions of sypathetic nervous system?

Answer 5

• pupillary dilation
• assists eyelid retraction
• vaso-constriction
• sweating

Question 6

What are the main functions of parasympathetic nervous system?

Answer 6

• smooth muscle of iris (sphincter pupillae)
• muscles in cilliary body (control thickness of lens)
• lacrimal glands
• salivary and mucosal glands
• smooth muscles of resp and GI tract

Question 7

Where does the sympathetic outflow to the whole body arise from?

Answer 7

the thoracolumbar portion (T1-L2)

Question 8

Where are the cell bodies found?

Answer 8

in the lateral horn of the grey matter

Question 9

Where does the parasympathetic outflow to the whole body arise from?

Answer 9

-craniosacral portion
cranial (4 cranial nerves)
sacral (s2,3,4) - pelvic splanchnics

Question 10

At what spinal level do pre-ganglionic sympathetics destined for the head and neck arise from?

Answer 10

T1/2

Question 11

What do the pre-ganglionic sympathetics have to do before they can synapse?

Answer 11

they must ascend the sympathetic chain to reach the neck before synapsing

Question 12

Where do they synapse?

Answer 12

in the superior cervical ganglion

Question 13

What is in the superior cervical ganglion?

Answer 13

• located opposite the 2nd and 3rd cervical vertebrae

- cell bodies of the post-ganglionic sympathetic nerve

Question 14

What happens after the sympathetics have synapsed?

Answer 14

They join to the common cartoid artery and follow its 2 branches

Question 15

What follows the ECA?

Answer 15

the nerves that have branches to distribute across the face.g. sweat glands and hair follicles

Question 16

What follows the ICA?

Answer 16

the nerves that need to supply the eye (into the orbit)

Question 17

What branch of the ICA will the nerve follow to get to the orbit?

Answer 17

the opthalmic branch of the ICA - can then supply eye lid and pupil

Question 18

What is myosis?

Answer 18

contraction of the pupil

Question 19

What does “unopposed pasrasympathetics” mean?

Answer 19

normally have sympathetic and parasympathetic to balance out - if you lose sympathetic innervation, you get “unopposed parasympathetic” - causing it to constrict

Question 20

What does pathology in the apex of the lung or the CCA cause?

Answer 20

autonomic dysfunction in the eye and face

Question 21

What would a person with a tumour in the apex of their lung present with and why?

Answer 21

• compression of the CCA and therefore the cranial nerves
• Partial ptosis and myosis and anhydrous (lack of sweating)
• unapposed parasympathetics causing contraction of the eye

Question 22

Why only partial ptosis?

Answer 22

most of LPS works (as result of oculomotor nerve) but a part of it uses sympathetic innervation hence only partial

Question 23

What are the triad of symptoms caused by?

Answer 23

horners syndrome - think about neck and chest

Question 24

What cranial nerves carry parasympathetics out from the brain stem?

Answer 24

oculomotor
vagus
facial
glossopharyngeal

Question 25

Where do parasympathetics arise from?

Answer 25

2 regions of the spinal cord (cranial region and sacral region)

Question 26

Where does the parasympathetic innervation to the head and neck arise from?

Answer 26

parasympathetic nuclei

Question 27

What is parasympathetic nuclei?

Answer 27

collections of pre ganglionic parasympathetic nerve cell bodies

Question 28

What is different about the parasympathetic preganglionic nerves compared to sympathetic preganglionic?

Answer 28

they are longer and travel a longer distance before reaching their associated ganglia as the ganglia lie closer to their effector tissues - note that once they synapse within their ganglia, their post ganglionic neurone is comparatively shorter

Question 29

What are the parasympathetic ganglia?

Answer 29

4 discrete ganglia (unlike the chain of ganglia with the sympathetics) - ciliary - submandibular - pterygopalatine - otic

Question 30

How do the parasympathetics reach the ganglia?

Answer 30

they hitch hike on CN's 3,7,9,10

Question 31

What happens once the parasympathetics reach the ganglia?

Answer 31

they ALL hitch hike onto the branches of the trigeminal nerve

Question 32

What are the 4 parasympathetic nuclei?

Answer 32

- edinger westphal!!!!!! - superior salivary - inferior salivary - dorsal motor

Question 33

What are the target tissues of the parasympathetics?

Answer 33

- sphincter pupillae (pupil constrictor) - cilliary muscle (controls lens) - lacrimal gland - mucosal glands (nasal, resp, oral mucosa) - salivary glands

Question 34

What is the rough of parasympathetics on CN III?

Answer 34

- parasympathetic arise from EWN (nucleus) - parasympathetic fibres emerge with CN III fibres - synapses at the ciliary ganglion (at the back of the orbit) where the parasympathetics hitch hike onto CN Va

Question 35

What does the parasympathetics do to the eye?

Answer 35

- acts on the ciliary muscle to alter the shape of the lens | - acts on sphincter pupillae muscle to constrict the pupil

Question 36

What nerve senses light?

Answer 36

the optic nerve - sends signals to the optic chiasm and the optic tract

Question 37

DRAW OUT THE PUPILLARY LIGHT REFLEX

Answer 37

-why do both of the eyes constrict when light is shone in 1 of the eyes

Question 38

What is anisocoria?

Answer 38

a condition characterised by an unequal size of the eyes pupils

Question 39

What branches of the facial nerve do the parasympathetics reach their targets via?

Answer 39

-chorda tympani and greater petrosal

Question 40

Where are the ganglia for the facial nerves parasympathetics?

Answer 40

- pterygopalatine ganglia (pterygopalatine fossa) | - submandibular ganglia

Question 41

After synapsing, where do the post-ganglionic parasympathetics go?

Answer 41

-run with the distal branches of the trigeminal (lingual) nerve

Question 42

What else does the chord tympani supply?

Answer 42

-taste to the anterior 2/3 of the tongue | its ganglia is sensory so will be found in the geniculate ganglion

Question 43

Which of the branches of CN IX does the parasympathetic run along?

Answer 43

-tympanic nerve (which supplies the middle ear)

Question 44

Where does the parasympathetics go after running with the tympanic nerve?

Answer 44

the parasympathetics exit the middle ear as the lesser petrosal nerve

Question 45

Where does the lesser petrosal nerve synapse?

Answer 45

in the otic ganglion in the infra temporal fossa

Question 46

Where do the post-ganglionic parasympathetics go?

Answer 46

hitch hike on the CN Vc -auriculotemporal nerve to the parotid gland

Question 47

Where do CNX pre-ganglionic parasympathetics run?

Answer 47

within CNX and its branches

Question 48

Where are the ganglia?

Answer 48

at or in the target tissue

Question 49

What is the target tissue for parasympathetics on CNX?

Answer 49

- mucosal glands in pharynx/larynx - smooth muscle of oesophagus and trachea - smooth muscle and mucosal glands within rest of respiratory and GI tract - Heart