A21 - Autonomic Nerve supply to the head and neck

Question 1

How are sympathetic and parasympathetic fibres passed from the CNS to the organs?

Answer 1

Via a pre-ganglionic fibre which connects the CNS to the ganglion which synapses and travels along a post ganglionic fibre to the organ.

Question 2

What neurotransmitter is associated with sympathetic ganglion?

Answer 2

acetyl choline

Question 3

What neurotransmitter is associated with sympathetic supple to the organ?

Answer 3

noradrenaline

Question 4

Where is the cervical part of the sympathetic chain situated?

Answer 4

in retropharngeal space the neck region

Question 5

Where does the internal carotid artery plexus come from?

Answer 5

it arises form the superior ganglion and carries sympathetic fibres to the internal carotid artery plexus

Question 6

How does sympathetic supply reach the extra-cranial structures?

Answer 6

post ganglionic fibres are carried by the branches of the external artery

Question 7

How does sympathetic supply reach the inta-cranial structures?

Answer 7

post ganglionic fibres are carried on the internal carotid artery and the branches

Question 8

Describe how sympathetic fibres travel from the Sympathetic Chain to the Organs.

Answer 8

1. exit the spinal cord via T1
2. travels up the cervical sympathetic chai
3. synapses in one the the sympathetic chain ganglia
4. post ganglionic fibres then travel to the surface of carotid arteries
5. then carried to the skin and organs via the pre -atrial plexus

Question 9

What neurotransmitter is associated with parasympathetic ganglion?

Answer 9

acetyl choline

Question 10

What neurotransmitter is associated with parasympathetic supple to the organ?

Answer 10

acetyl choline

Question 11

Where are parasmypathetic ganglion located?

Answer 11

through out the body but there are 5 main ones

ciliary, pteryopalatine, submandibular, otic and vagus

Question 12

what are the different types of tears you get?

Answer 12

basal
reflex
emotionial

Question 13

What are basal tears?

Answer 13

the are produces all the time and clean dust from the eyes and provides lubrication

Question 14

What is he function of reflex tears?

Answer 14

produced in response to mechanical/chemical stimuli

Question 15

What is the efferent (motor) limb of reflex tears?

Answer 15

CN Va

Question 16

What is the afferent (sensory) limb of reflex tears?

Answer 16

parasympathetic which is derived from the facial nerve

Question 17

What effect will cutting Va have on reflex tears ?

Answer 17

will stop reflex tears but emotional tears still function

Question 18

How are emotional tears stimulates?

Answer 18

by the brain emotion centres which produce parasympathetic supply to the lacrimal gland

Question 19

Describe the lacrimal production of tears.

Answer 19

1. facial nerve passes through the internal acoustic meatus and branches into the greater petrosal nerve
2. the greater petrosal nerve carries pre-ganglionic fibres
3. this reaches a ganglion and synapses
4. the post ganglionic fibres join Vb at foramen rotundrum and reach the lacrimal gland

Question 20

What causes blushing?

Answer 20

sympathetic vasodilators increases the blood flow to the face via the facial vein

Question 21

Why does blushing occur in the face?

Answer 21

the skin is thin and the blood vessels are superficial

Question 22

What is the sympathetic supply to the eye?

Answer 22

• eyes open wider
• allow more light in
• focus on far objects

Question 23

What is the parasympathetic supply to the eye?

Answer 23

• allows less light in
• focus on near objects
• contracts orbicularis oculi

Question 24

How is light let into the eye?
parasympathetic
sympathetic

Answer 24

parasympathetic - the sphincter pupillae contracts via the fibres in the oculomotor nerve

sympathetic - the dilator pupillae causes the pupil to dilate via fibres on the ophthalmic branch of internal carotid

Question 25

how do parasympathetic supply increase ability to focus on near objects?

Answer 25

1. parasympathetic supply acts on the ciliary muscle causing it to contract 2. the suspensory ligament of the lens cause it to relax and flatten out 3. the allows the lens to focus

Question 26

How do we focus on objects in the distance?

Answer 26

there is no parasympathetic stimulus so the ciliary muscle relaxes and the suspensory ligament contracts resulting in the lens slimming

Question 27

How does sympathetic supply allow the eyes to open wider

Answer 27

1. pre-ganglionic fibres synapse at the superior cervical ganglia 2. They travel along the internal carotid nerve (via the artery) 3. The post-ganglionic fibres follow onto the ophthalmic branch and supply to orbital structure

Question 28

What muscle allows us to open the eyes wide?

Answer 28

levator palpebral - skeletal and smooth

Question 29

What supplies the smooth muscle of the eye?

Answer 29

autonomic fibres travel along the ciliary nerves carrying post-ganglionic fibres, the pre- ganglionic fibres synapse at the ciliary ganglion

Question 30

Describe the parasympathetic supply to the submandibular and sublingal gland.

Answer 30

chorda tympani branches from the facial nerve and follows the lingual nerve to synapse at the submandibular ganglion which will then supply the glands