Session 6

Question 1

The sympathetic outflow to the whole body arises from the

Answer 1

Thoracolumbar portions T1-L2 of spinal cord (lateral horn)

Question 2

Preganglionic sympathetic fibres on exiting spinal cord usually synapse with their

Answer 2

Post ganglionic nerve in a sympathetic chain ganglion

Question 3

Sympathetic outflow to the head and neck region arises from

Answer 3

T1/T2 segments

Question 4

Preganglionic fibres reaching the neck have to

Answer 4

ascend from thorax, up sympathetic chain to reach the neck

Synapse on one of the upper (cervical) ganglia of the chain

In superior and middle cervical ganglia

Question 5

Post ganglionic sympathetic fibres reach their target tissues in the head and neck by

Answer 5

Hiking onto blood vessels

Question 6

Parasympathetic outflow arises from

Answer 6

2 regions of CNS

Top and bottom of spinal cord

Cranial (brainstem) and sacral region- craniosacral outflow

Question 7

Cranial portion supplies

Answer 7

Parasympathetic innervation to the head and neck, and thorax and abdomen via CN X

Question 8

What are nuclei

Answer 8

Collections of preganglionic parasympathetic nerve cell bodies

Question 9

Nuclei lie in

Answer 9

Brainstem, often in close proximity to the nuclei of cranial nerves

Hitch hike on them when leaving brainstem

Question 10

Parasympathetic preganglionic nerves compared to sympathetic preganglionic nerves

Answer 10

Parasympathetic have longer preganglionic nerves

Travel longer distance before reaching their associated ganglia

Post ganglionic neurone is shorter

Question 11

Parasympathetic outflow does not have a chain of ganglia but instead has

Answer 11

A number of discrete ganglia- 4

Question 12

4 head and neck parasympathetic ganglia

Answer 12

Ciliary CN 3
pterygopalatine CN 7
submandibular CN 9
and otic CN 10

Question 13

What happens once the post ganglionic parasympaethic fibres reach their ganglia

Answer 13

Jump ship and hitch hike onto branches of the trigeminal nerve, to reach the target tissues

Question 14

The parasympaethic fibres associated with the vagus nerve do not have

Answer 14

A discrete ganglion within the head, but instead travel some distance with the vagus nerve down the neck and into the thorax

Question 15

The parasympathetic fibres remain with the vagus nerve until the autonomic fibres meet and synapse in

Answer 15

Ganglia very close to or within its target effector tissues

E.g. mucous membrane glands, smooth muscle of larynx, pharynx, thorax abdomen and heart

Question 16

Autonomic nervous system controls

Answer 16

Non-voluntary actions such as smooth muscle, cardiac muscle and glands

Question 17

Sympathetic fight or flight response direct effect on target tissues (most important)

Answer 17

Smooth muscles in eyelid (superior tarsal muscle) = eyelid retraction

Smooth muscle in the iris (dilator pupillae) = dilates pupils

Sweat glands

Question 18

Sympathies fight or flight response effect on target tissues (other)

Answer 18

Smooth muscle of blood vessels (skin and gut) = constricts

Smooth muscle of respiratory tract and gastrointestinal tract (bronchodilator airways and decrease gut motility)

Cardiac muscle (increased rate and force of contraction)

Question 19

Parasympathetic effects on target tissues (most important)

Answer 19

Smooth muscle of iris (sphincter pupillae) = constricts pupil
Smooth muscle in ciliary body (makes lens fatter)
Lacrimal glands increase secretions
Salivary glands increase secretions

Question 20

Parasympathetic effects on target tissues (other)

Answer 20

Mucosal gland secretions increase
Smooth muscle of respiratory and GI tract contracts

Cardiac muscle (decreased rate and force of contraction)

Question 21

Difference between position of cell body in pre and post ganglionic

Answer 21

Question 22

Sympathetic route to neck in detail up to post ganglionic

Answer 22

Question 23

Sympathetic route from post ganglionic onwards

Answer 23

Question 24

Points where sympathetic innervation to head and neck structures can be damaged

Answer 24

1st order neurone within CNS
2nd order neurone exiting CNS and within sympathetic chain
3rd order neurone running with blood vessels

Question 25

Key anatomical relations to sympathetic nerves reaching H and N structures

Answer 25

Common carotid or internal carotid e.g. carotid artery dissection or aneurysm

Apical lung cancer e.g. Pancoasts tumour

Question 26

Clinical manifestation of interruption of sympathetic innervation to face and eye

Answer 26

Question 27

Why does interruption of sympathetic innervation lead to partial ptosis (not complete)

Answer 27

Levator Palpebrae Superioris LPS contracts to elevate (retract) the upper eyelid

2 muscle types within it contribute

Skeletal (somatic)- majority
Smooth muscle (autonomic)- smaller

Question 28

Answer 28

Question 29

Answer 29

Question 30

What happens when you have light in left pupil

Answer 30

Question 31

Parasympathetic associated with facial nerve reach target tissues via

Answer 31

Greater petrosal nerve (carries only pre-gang parasympathetic fibre)

Chorda tympani nerve

Question 32

Parasympathetics associated with CN IX pathway

Answer 32

Branch supplying sensory to middle ear (tympanic nerve): pre-ganglionic parasympathetic fibres hitch hike with it

Question 33

Pre-ganglionic parasympathetics associated with CN IX exit middle ear as

Answer 33

Lesser petrosal nerve which runs to otic ganglion (in infratemporal fossa)

Question 34

Post ganglionic parasympathetics associated with CN IX exit ganglion to join with

Answer 34

Auriculotemporal nerve (Vc branch) to supply parotid gland

Question 35

Parasympathetics associated with Vagus nerve pathway

Answer 35

Question 36

Summary for parasympathetic innervation to head and neck

Answer 36