Autonomic nervous system

Question 1

List the efferent divisions of the autonomic nervous system

Answer 1

Sympathetic nervous system

Parasympathetic nervous system

Question 2

Where does the sympathetic originate in the CNS?

Answer 2

“Thoracolumbar outflow” cell body of a presynaptic neuron is located on the lateral horn of T6 to L2/L3

Question 3

Where does the parasympathetic originate in the CNS?

Answer 3

• Craniosacral: Cell body of a presynaptic neuron is in cranial nerves and nucleus
  III - Oculomotor n. - Eddinger Westphal
  VII - Facial n. - Superior Salivatory
  IX - Gasophalangeal n. - Inferior Salivatory
  X - Vagus n. - Dorsal Motor of vagus n.
• Sacral outflow: the S2-S4 grey matter of intermediate zone

Question 4

What is the effect of SNS?

Answer 4

Catabolic system

• Fight
• Flight
• Fright

Question 5

What is the effect of PNS?

Answer 5

Anabolic system

• Rest
• Digest

Question 6

Synapse location of presynaptic and postsynaptic neurons of the SNS?

Answer 6

1) At the same level in the sympathetic chain
2) Ascending or Descending in the sympathetic chain
3) Presympatheric neurons exit sympathetic chain and branch out to form abdominopelvic splanchnic n. and synapse at preaortic and prevertebral ganglia outside synaptic chain. neuron goes in and out white matter channel.

Question 7

Synapse location of presynaptic and postsynaptic neurons of the PNS?

Answer 7

1) CN III, VII, IX synapse at the head of ganglia

2) CN X (Vagus) + S2-S4 (Pelvic splanchnic) synapse at terminal ganglia

Question 8

What is the length of the SNS neurons?

Answer 8

Presynaptic short

Postsynaptic Long

Question 9

What is the length of the PNS neurons?

Answer 9

Presynaptic Long

Postsynaptic Short

Question 10

Neurotransmitters SNS?

Answer 10

Adrenic neurons
Presynaptic release Acetylcholine
Postsynaptic release Noradrenalin

Question 11

What are the SNS receptors?

Answer 11

Androgenic receptors -

• B1 - heart - Located SA Node and Myocardium
• B2 - Lungs
• A1 - vessels

Question 12

Neurotransmitters PNS?

Answer 12

Cholinergic neurons

Presynaptic and Postsynaptic release acetylcholine (Ach)

Question 13

What are the PNS receptors?

Answer 13

Muscarine receptors

• M2 - heart - SA Node
• M3 - Lungs

Question 14

What effect does SNS have on the heart, lungs and vessels?

Answer 14

• Heart: Increase heart Rate
• Lungs: Dilate bronchioles
• Vessels: Dilates blood vessels

Question 15

What effect does PNS have on the heart and lungs?

Answer 15

• Heart: Decrease heart rate

- Lungs: Constricts bronchioles

Question 16

What is the Afferent motor pathway

Answer 16

Sends sensory feedback on visceral sensations back to the brain

Question 17

What visceral sensations travel with the SNS?

Answer 17

Pain
Distention
Ischaemia
Chemical
Strong contraction

Question 18

What visceral sensations travel with the PNS?

Answer 18

Some pain

unconscious sensation

Question 19

How do the visceral afferent fibres carry pin signals from the heart to the primary somatosensory cortex?

Answer 19

• some pain and unconcious travel with PNS and are transmitted to the solitary nucleus in medulla.
• Other sensations acompany SNS Nerve fibres in retrograde