PNS

Question 1

How is autonomic outflow controlled?

Answer 1

Nucleus solitary tract -> brain stem

Question 2

What types of fibres are preganglionic and postganglionic fibres?

Answer 2

Preganglionic are myelinated B fibres.

Postganglionic are non-myelinated C fibres.

Question 3

Where are parasympathetic ganglia found?

Answer 3

Near innervated tissues

Question 4

Which neurotransmitter is released from preganglionic neurons?

Answer 4

Acetylcholine

Question 5

What is the function of the ganglia?

Answer 5

Integrate, amplify info input.

Question 6

What is the ratio of pre to post ganglionic fibres in sympathetic NS?

Answer 6

1:20, more than one preganglionic neuron synapses single post ganglionic fibre

Question 7

What is the ratio of pre to post ganglionic fibres in parasympathetic NS?

Answer 7

1:1

in gut, 1:8000

Question 8

What is the effect of Nitric oxide?

Answer 8

Mediates muscle relaxation of stomach induced by vagal PNS stimulation. increase in cGMP.