Organisation of the Autonomic Nervous System

Question 1

What are the effector organs of the ANS?

Answer 1

Smooth Muscle
Secretory Glands
Cardiac Muscle

Question 2

How many neurones comprise the general pathway of the ANS?

Answer 2

2:
One in the CNS (preganglionic)
One in the PNS.
(post-ganglionic)

Question 3

Which neurotransmitter is released between preganglionic and postganglionic neurones in both the sympathetic and parasympathetic NS?

Answer 3

Acetylcholine

Question 4

Which receptor is found at the synapse between preganglionic and postganglionic neurones in both the sympathetic and parasympathetic NS?

Answer 4

Nicotinic Acetylcholine Receptors

Question 5

Which neurotransmitter is released between postganglionic neurones and effector organs in the parasympathetic NS?

Answer 5

Acetylcholine

Question 6

Which neurotransmitter is released between postganglionic neurones and effector organs in the sympathetic NS?

Answer 6

Adrenaline and Noradrenaline

Question 7

Which receptor is found between postganglionic neurones and effector organs in the sympathetic NS?

Answer 7

α or β Adrenoceptors

Question 8

Which receptor is found between postganglionic neurones and effector organs in the parasympathetic NS?

Answer 8

Muscarinic Receptors

Question 9

Where are parasympathetic ganglia found?

Answer 9

In the walls of the effector organs or near branches of CNV

Question 10

Where are sympathetic ganglia found?

Answer 10

Paravertebral ganglia - Sympathetic trunk

Prevertebral ganglia - Between paravertebral ganglia & target organ. Splanchnic nerves synapse here.

Question 11

What type of innervation do sweat glands receive? Sympathetic, parasympathetic or both?

Answer 11

Sympathetic only

Question 12

Where do parasympathetic fibres originate from?

Answer 12

Cranio-sacral sources:
CN3, CN7, CN9, CN10
S2, S3, S4

Question 13

Where do sympathetic fibres originate from?

Answer 13

Thoraco-lumbar sources:

T1-L2/3

Question 14

Where are pre-ganglionic fibres found in the parasympathetic nervous system? (Don’t confuse with origin)

Answer 14

Either within branches of the vagus nerve or as part of spinal segmental nerves originating from S2-S4.

Question 15

Where are the somata that constitute the origin of parasympathetic outflow to the head?

Answer 15

Within the brainstem.

Question 16

How do axons of pre-ganglionic neurones that constitute parasympathetic outflow to the head travel to their targets?

Answer 16

By hijacking cranial nerves 3, 7, 9 and 10.

Question 17

How many different ganglia can parasympathetic pre-ganglionic neurones in the head synapse/terminate on?

Answer 17

4

Question 18

Where do parasympathetic pre-ganglionic axons travelling as part of CN3 terminate?

Answer 18

In the ciliary ganglion.

Question 19

Where do parasympathetic pre-ganglionic axons travelling as part of CN7 terminate?

Answer 19

In the pterygopalatine ganglion or submandibular ganglion.

Question 20

Where do parasympathetic pre-ganglionic axons travelling as part of CN9 terminate?

Answer 20

In the otic ganglion.

Question 21

The ganglia at which parasympathetic pre-ganglionic axons terminate lie in association with branches of which cranial nerve?

Answer 21

CNV (trigeminal nerve)

Question 22

Where do parasympathetic pre-ganglionic axons travelling as part of CN10 terminate?

Answer 22

Pre-ganglionic axons from CN10 do not terminate in discrete parasympathetic ganglia.

Question 23

What are the names of the 4 pre-ganglionic nuclei?

Answer 23

Edinger-Westphal
Superior Salivatory
Inferior Salivatory
Dorsal Vagal Motor Nucleus

Question 24

Axons from which pre-ganglionic nucleus hijacks CN3?

Answer 24

Edinger-Westphal

Question 25

Axons from which pre-ganglionic nucleus hijacks CN7?

Answer 25

Superior Salivatory

Question 26

Axons from which pre-ganglionic nucleus hijacks CN9?

Answer 26

Inferior Salivatory

Question 27

Axons from which pre-ganglionic nucleus hijacks CN10?

Answer 27

Dorsal Vagal Motor Nucleus

Question 28

Parasympathetic outflow to which organs originate from the edinger-westphal nucleus?

Answer 28

Eye

Question 29

Parasympathetic outflow to which organs originate from the superior salivatory nucleus?

Answer 29

Nasal Gland Lacrimal Gland Submandibular Gland Sublingual Gland

Question 30

Parasympathetic outflow to which organs originate from the inferior salivatory nucleus?

Answer 30

Parotid Gland

Question 31

Parasympathetic outflow to which organs originate from the dorsal vagal motor nucleus?

Answer 31

Wide distribution.

Question 32

Which action(s) arise from parasympathetic outflow from the edinger-westphal nucleus?

Answer 32

Pupillary constriction

Question 33

Which action(s) arise from parasympathetic outflow from the superior salivatory nucleus?

Answer 33

Serous secretions

Question 34

Which action(s) arise from parasympathetic outflow from the inferior salivatory nucleus?

Answer 34

Serous secretions

Question 35

Which action(s) arise from parasympathetic outflow from the dorsal vagal motor nucleus?

Answer 35

Laryngeal function and actions in the rest of the body's viscera

Question 36

What is the length of sympathetic preganglionic fibres relative to parasympathetic preganglionic fibres?

Answer 36

Sympathetic preganglionic fibres tend to be shorter than parasympathetic preganglionic fibres.

Question 37

In the autonomic nervous system, are all preganglionic fibres myelinated? What about postganglionic fibres?

Answer 37

In the autonomic nervous system: All preganglionic fibres are myelinated. All postganglionic fibres are unmyelinated.

Question 38

What are the 3 possible modes of termination for sympathetic pre-ganglionic axons?

Answer 38

1- May synapse in chain at same level of origin (paravertebral nerves). 2- May synapse in chain at a different level to origin 3- May not synapse in paravertebral chain (splanchnic nerves).

Question 39

What are rami communicantes?

Answer 39

White rami communicantes carry preganglionic sympathetic axons of T1-L2/3 spinal nerves to the sympathetic trunk. Gray rami communicantes carry postganglionic sympathetic axons to effector organs.

Question 40

What is the difference between grey and white rami?

Answer 40

White are myelinated, grey are not.

Question 41

What are the two divisions of sympathetic ganglia?

Answer 41

Paravertebral ganglia and prevertebral ganglia.

Question 42

What is the paravertebral chain?

Answer 42

A chain of sympathetic ganglia that lie alongside the vertebral column bilaterally, extending from the base of the skull to the coccyx.

Question 43

What are prevertebral ganglia?

Answer 43

Ganglia at which sympathetic pre-ganglionic nerve fibres synapse with their post-ganglionic counterparts. Nerves that synapse here innervate pelvic viscera. These ganglia are proximal to their target organs.

Question 44

*CHECK*Which 3 ganglia of the prevertebral chain supply the head and neck with its sympathetic supply?

Answer 44

*CHECK*Superior Cervical Ganglion Middle Cervical Ganglion Inferior Cervical Ganglion

Question 45

What is the sympathetic trunk?

Answer 45

A bundle of nerve fibres that allows nerve fibres to travel to spinal nerves that are superior and inferior to the level in which they originate.

Question 46

Where do sympathetic preganglionic fibres that supply the head and neck originate?

Answer 46

T1-T2

Question 47

Where is the superior cervical ganglion located?

Answer 47

Anterior to vertebrae C1, C2, C3 and C4.

Question 48

Where is the middle cervical ganglion located?

Answer 48

Anterior to C6 (but small and often absent).

Question 49

Where is the inferior cervical ganglion located?

Answer 49

Anterior to C7.

Question 50

The inferior cervical ganglion sometimes fuses with the first thoracic ganglion to form what?

Answer 50

The cervicothoracic (stellate) ganglion.

Question 51

How do sympathetic post-ganglionic fibres reach their targets in the head and neck?

Answer 51

By hitch-hiking the arterial system of the head and neck via walls of the common, external and internal carotids.

Question 52

Which arteries does the superior cervical ganglion give branches to?

Answer 52

Internal and external carotid arteries.

Question 53

Which artery does the middle cervical ganglion give branches to?

Answer 53

Inferior thyroid artery.

Question 54

Which arteries does the inferior cervical ganglion give branches to?

Answer 54

Subclavian and vertebral arteries.

Question 55

What do sympathetic postganglionic axons often mingle with (but do not synapse with) in autonomic plexuses?

Answer 55

Parasympathetic preganglionic axons

Question 56

How do the effects of the parasympathetic nervous system compare to that of the sympathetic nervous system in terms of degree of localisation?

Answer 56

Parasympathetic effects are more discrete and localised than sympathetic effects.

Question 57

Where is the integration and command centre for autonomic functions?

Answer 57

In the hypothalamus.

Question 58

What does the abdominal aortic plexus consist of?

Answer 58

The coeliac plexus The superior mesenteric plexus The inferior mesenteric plexus