W21-L4: Autonomic Nervous System

Question 1

Where do all the sympathetic pathways originate from?

Answer 1

all of sympathetic come out of thoraco lumbar region

Question 2

Where do all the parasympathetic pathways originate from?

Answer 2

all of para are cranio (cranial nerves)-sacral

Question 3

Do any autonomic pathways originate in cervical or lumbar enlargement?

Answer 3

No

Question 4

What are the two columns of sympathetic ganglia?

Answer 4

Prevertebral ganglia

Para-verteberal ganglia

Question 5

What are the pre-ganglionic fibres for both para and sympathetic fibres?

Answer 5

Lightly myelinated/unmyelinated, uses Acetylcholine on nicotinic receptors (longer in post-ganglionic)

Question 6

What are the post-ganglionic fibres for both para and sympathetic fibres?

Answer 6

All unmeylinated, longer in sympathetic (NA, ACh on muscarinic) and parasympathetic ACh on muscarinic

Question 7

T/F Autonomic pathways contrast with typical CNS circuits where glutamate and GABA are the primary transmitters

Answer 7

True

Question 8

What is co-transmission?

Answer 8

More than one transmitter being released at one time

Question 9

T/F More than one transmitter release site per axon in ANS to organs

Answer 9

True

Question 10

What is extra-junctional receptors?

Answer 10

Receptors can be expressed remotely from the synapse

Question 11

Where do the preganglionic neurons of the sympathetic lie in the spinal cord?

Answer 11

Intermediolateral cell column

Question 12

What is the function of Paravertebral ganglia (sympathetic chain)?

Answer 12

primary source of vasoconstrictor neurons

Question 13

What is the function of Prevertebral ganglia (sympathetic chain)?

Answer 13

primary source of neurons innervating non-vascular smooth muscle
eg airway, reproductive smooth muscle

Question 14

What does divergence mean?

Answer 14

mechanism for coordinating effects in many tissues at once, Up to 200 ganglion neurons can be activated by one preganglionic neuron

Question 15

What does convergence mean?

Answer 15

Prevertebral ganglion neurons integrate more signals from multiple inputs

Question 16

What is the sympathoadrenal system?

Answer 16

adrenal medulla cells are innervated by sympathetic preganglionic
neurons release noradrenaline and adrenaline into the circulation broad activation of adrenoceptors throughout the body

Question 17

What is the pelvic ganglia?

Answer 17

relay station; relatively little integration made up of parasympathetic ganglion neurons which have unusually long axons: vulnerable to surgically- induced injury and many sympathetic neurones

Question 18

T/F sympathetic and parasympathetic systems always act antagonistically and in competition

Answer 18

False

Question 19

What is an example of ANS genuine antagonistic actions?

Answer 19

Heart rate, Heart contraction, airway relaxation

Question 20

What is an example of ANS functional antagonistic actions?

Answer 20

Pupil, bladder

Question 21

What is an example of ANS different but not opposite actions?

Answer 21

serous Salivary vs mucous salivary, tear secretion, vasoconstriction

Question 22

How do you distinguish sympathetic and parasympathetic nerves?

Answer 22

The only correct, unequivocal definition is anatomical: location of preganglionic neurons other properties are unreliable

Question 23

T/F Most autonomic reflexes involve the brain (supraspinal reflex) rather than only the spinal cord (spinal reflex)

Answer 23

True

Question 24

Where is the major integrative centre for autonomic function?

Answer 24

Caudal part of the NTS

Question 25

What is the most important brain region for coordination of autonomic output?

Answer 25

Paraventricular nucleus