1.8 Autonomic Nervous Sytstem

Question 1

What is the autonomic nervous system

Answer 1

Sub-division of the PERIPHERAL nervous system
Not under conscious control
Controls non-skeletal peripheral function (e.g. cardiac muscle, smooth muscle, internal organs and skin)

Question 2

Parasympathetic

Answer 2

Rest and digest (routine maintenance)

Question 3

Sympathetic

Answer 3

Fight or Flight (mobilisation and increased metabolism)

Question 4

Where do visceral motor nuclei originate

Answer 4

Hypothalamus

Question 5

Where do visceral motor neurones project

Answer 5

Brainstem or spinal cord (where they synapse with autonomic neurons- Parasympathetic or sympathetic)

Question 6

Autonomic neurons

Answer 6

Consist of two two neurons - pre and post ganglionic neuron

Question 7

Ganglion

Answer 7

Nerve cell cluster or group of nerve cell bodies

Question 8

Parasympathetic neurons

Answer 8

Long pre- ganglionic fibres
Short post ganglionic fibres

Ganglions close or embedded in effector tissues

Question 9

Sympathetic neurons

Answer 9

Short pre-ganglionic fibres
Long post-ganglionic fibres

Ganglions close to spinal cord

Question 10

Acceptiom to the two neuron arrangement in autonomic neurons

Answer 10

Adrenal gland

Question 11

Which neurotransmitters are released in parasympathetic neuron synapses

Answer 11

Pre- Ach
Post- Ach

Question 12

Which neurotransmitters are released in sympathetic neurons synapses

Answer 12

Pre- Ach
Post - NA (noradrenaline)

Question 13

Which neurotransmitters is released at adrenal gland

Answer 13

Secretes hormone not a NT
Adrenaline and noradrenaline
Secreted into bloodstream not synapse

Question 14

Lung tissue innervation

Answer 14

No sympathetic neurons

Question 15

Are ANS effects voluntary or involuntary

Answer 15

Involuntary

Question 16

What type of receptors mediate the effects within the ANS

Answer 16

Ion channels receptor (fast)
- nicotinic ACh receptor

Mediates response to ACh released from pre in all autonomic ganglia
Mediates response to Ach released by sympathetic nerves innervating the Adrenal Medulla

Question 17

Which receptor on post ganglionic fibres

Answer 17

G-protein coupled receptors
For muscarinic (Ach) or adrenergic receptors (NA release from post g.f or adrenaline via the blood)

Question 18

What happens if you block acetycholinestherase

Answer 18

Acetylcholine isn’t degraded in the synapse and so action potential continues

Question 19

Biosynthesis and metabolism of ACh

Answer 19

1. Choline and Acetyl coA enzymatically converted to ACh by choline Acetyl transferase
2. Packaged into vesicles
3. AP leads to Ca2+ influx and vesicle exocytosis/ NT release
4. Receptor activation (nicotinic or muscarinic)
5. Ach rapidly degraded by Ach esterase
6. Choline taken up into presynaptic terminal by choline uptake protein

Question 20

Biosynthesis and metabolism of NA

Answer 20

1. Tyrosine converted to DOPA by tyrosine hydroxylase
2. DOPA converted to dopamine by DOPA Decarboxylase
3. Dopamine packaged with dopamine beta hydroxylase to vesicles where it’s converted to NA
4. AP -> NT release
5. Receptor activation (adrenergic)
6. NA uptaken to pre synaptic terminal or glial cell and is then metabolised

Question 21

Biosynthesis and metabolism of adrenaline

Answer 21

1. Tyrosine converted to DOPA by tyrosine hydroxylase
2. DOPA converted to dopamine by DOPA decarboxylase
3. Dopamine and dopamine beta hydroxylase packaged together and converted to NA
4. NA converted to adrenaline in the cytoplasm by phenylethanol methyl transferase
5. AP -> NT release
6. Adrenaline diffuses into capillary and is transported to tissues in the body