PNS

Question 1

Peripheral nerves contain fibres that are axons of what neurones?

Answer 1

Afferent (sensory)
Efferent (motor)
Or both

Question 2

What types of neurones do all spinal nerves contain?

Answer 2

Both efferent and afferent

Question 3

What types of neurones do some cranial nerves contain and example for each?

Answer 3

Some cranial nerves contain only afferent fibres (optic nerve) or only have efferent fibres (hypoglossal nerve)

Question 4

Afferent neurones

They convey info from ……. At their ……. To the……

Answer 4

Sensory receptors
Peripheral ending
CNS

Question 5

Afferent neurones

Where do the longest part of their axon lie?

Answer 5

Outside the CNS and is part of the PNS

Question 6

What are afferent neurones also referred to as and why?

Answer 6

First order neurones

They are the first cells entering the CNS

Question 7

What do efferent neurones do?

Answer 7

They carry signals out from the CNS to muscles, glands and other tissues

Question 8

What are efferent neurones subdivided into?

Answer 8

Somatic NS (voluntary)
Autonomic NS (involuntary)

Question 9

Somatic NS
What does it innervate?
How many axons/nurones does it have?
Where do they go from & to?
Neurotransmitters?

Answer 9

Innervates skeletal muscle

Single myelinated neurone/axon from CNS directly to skeletal muscle, without synapse

Only neurotransmitter-acetyl choline
Only excitatory

Question 10

Autonomic NS
What does it innervate?
How many neurones involved?
Where do they go from and to?
Which neurotransmitters used?
How do they function?

Answer 10

Innervate smooth & cardiac muscle, glands & neurones in the GI tract (enteric NS) & other tissues

2 neurone chain, connected by synapse

First neurone = cell body in CNS, pre ganglionic fibre, synapse outside CNS (autonomic ganglion), post ganglionic fibre, muscle/gland

Pre=always Ach
Post=Ach (excitatory) or NAd (inhibitory)

Function without conscious awareness (involuntary)

Question 11

What can the autonomic NS be divided into?

Answer 11

Sympathetic and parasympathetic

Question 12

Where does the sympathetic NS leave the CNS?

Answer 12

From the thoracic & lumbar regions (T1 - L2) of spinal cord

Question 13

Where do most ganglia Iie in the sympathetic NS?

Answer 13

Most of the ganglia lie cloe to the spinal cord and form 2 chains of ganglia, one on each side of the cord, known as sympathetic trunks

Question 14

Sympathetic

Are the preganglionic and postglionic axons short or long?

Answer 14

Pre = short
Post = long

Question 15

Sympathetic

Where do the preganglionic axons synapse?

Answer 15

At lateral horn T1 - L2

Question 16

Sympathetic

What neurotransmitters and receprors are found at the pre and post ganglionic synapses?

Answer 16

Ach to nicotinergic

NAd to adrenergic

Question 17

What does the efferent sympathetic NS supply?

Answer 17

Visceral organs and structures of superficial body regions

Question 18

Does the sympathetic or parasympathetic division contain more ganglia?

Answer 18

Sympathetic contains more than parasympathetic

Question 19

Sympathetic

The effects are ….. by the …….

Answer 19

Amplified

Adrenal glands

Question 20

How do the adrenal glands amplify the effects of the sympathetic chain? What does this cause?

Answer 20

Release adrenaline directly into the blood

High blood pressure and Heart rate

Question 21

What does the sympathetic NS cause to the body?

Answer 21

Increases heart rate
Increases contractility
Vasoconstriction 
Bronchodilation
Reduces gastric motility
Sphincter contraction
Decreased gastric secretions
Male ejaculation

Question 22

Where does the parasympathetic axons leave the CNS?

Answer 22

From the brainstem and sacral portion of spinal cord

Question 23

Where does cranial outflow come from?

Answer 23

Comes from brain

Question 24

Which cranial nerves are parasympathetic?

What do the parasympathetic fibres do in these cranial nerves?

Answer 24

10, 9, 7, 3
CN3-occulomotor, pupil constriction
CN7-facial, to salivary glands
CN9- glossopharyngeal, for swallowing reflex
CN10-vagus, thorax and abdomen, (increased GI motility, decreased HR, vasodilation)

Question 25

Where do cranial nerve cell bodies lie?

Answer 25

Cranial nerve nuclei in the brainstem

Question 26

The parasympathetic fibres of the cranial nerves innervate organs of the …..

Answer 26

Head, neck, thorax and abdomen

Question 27

What does the sacral outflow supply?

Answer 27

Supplies remaining abdominal and pelvic organs

Question 28

Parasympathetic

Where do the ganglia lie relative to the organs that the post ganglionic neurones innervate?

Answer 28

Within/very close

Question 29

Parasympathetic

Are the preganglionic and postglionic axons short or long?

Answer 29

Pre = long
Post = short

Question 30

Parasympathetic

What neurotransmitters and receprors are found at the pre and post ganglionic synapses?

Answer 30

Pre = Ach to nicotinergic
Post = Ach to muscarinic

Question 31

What does the parasympathetic NS cause to the body?

Answer 31

Decrease heart rate
Decrease contractility
Vasodilation 
Bronchoconstriction 
Increase gastric motility
Sphincter relaxation 
Increased gastric secretions
Male erection

Question 32

What is the enteric NS?

Does it need to autonomic NS or can it operate independently?

Answer 32

NS of the GI tract

Can operate independently of the autonomic NS