Parasympathetic Nervous System

Question 1

where does the oculomotor of the parasympathetic nervous system synapse

Answer 1

Comes from the mid brain and will synapse at the ciliary ganglion and result in pupillary constriction

Question 2

Where does the facial nerve of the parasympathetic nervous system synapse

Answer 2

-From the pronto- medulary junction - (junction in ponds and medulla)
synpases in prontopalatine ganglion and supplies paratoid glands
- synapses in submandular ganglion and supplies the salivary glands

Question 3

What are the parasympathetic ganglia of the head

Answer 3

COPS
ciliary= innovates lend of eye muscle
Otic- ear gland 
Pterygopalatine- lacrimal gland
Submandibular = salivary gland

Question 4

What does the vagus nerve of the parasympathetic target supply

Answer 4

• heart, trachea, lungs, stomach, small intestines, liver, large intestine, adrenal gland, kidney (distal thrid of tranverse colon)

Question 5

What neurons in the parasympathetic NS supplies large intestines, bladder and reproductive organs

Answer 5

S2-S4= post ganglionic neutron is the PELVIC SPLANCHNIC NERVE (sacral fibres)

Question 6

What receptors do ACh effect in para

Answer 6

IN THE CNS

• nicotinic preganglion
• muscarinic in post ganglion

Question 7

What are the 6 steps of chogenic transmission of Ach

Answer 7

1. Supply (transmitter precursor)
2. synthesis (transmitter)
3. storage. ((transmitter)
4. release. (transmitter)
5. inactivation (transmitter)
6. feedback (inhibition of release)

Question 8

What does it mean by the supply of Ach and what drug do we associate with it

Answer 8

• uptake of choline into nerve endings (High affinity carrier)
• Na+ dependent reaction
• Hemicholinium = -competitive inhibitor of choline
• activity dependent block of cholinergic transmission
• no clinical use as too wide spread
• more stimulate more effective H is

Question 9

What is the synthesis of Ach and competitive inhibition for the enzyme

Answer 9

• • Ach catalysed by ChAT

- triethylchlone competitively binds to choline acetyltransferase (ChAT)

Question 10

What is the equation for Ach

Answer 10

Choline+ Acetyl co enzyme A—-> acetylcholine + coenzyme A

Question 11

What is the storage mechnism for Ach and drug inhibition of stores

Answer 11

• the Ach store maintained through energy dependent pump

- vesamicol drug - inhibition of pump- depletion of stores

Question 12

What does Acetyltriethylcholine do and how is it formed

Answer 12

• formed from triethylcholine catalysis by choline acetyl transferase
• not specific released as false transmitter
• weak postsynaptic effect
• depends on how potent postsynaptic receptors are compared to with natural transmitter

Question 13

How will Ach be released

Answer 13

• binds to cell membrane
• requires Ca 2+ into nerve endings
• released by exocytosis

Question 14

How does Ach give feedback

Answer 14

• Ach act back onto MR inhibits neurotranmitter release

- can work with ATP to cause inhibition of adenosine receptors

Question 15

How is Ach removed from synaptic cleft

Answer 15

• hydrolysis by tissue acetylcholinesterase
• broken down from acetylcholine to acetate and choline
• non reversible

Question 16

Which enzymes and what inhibits acetylcholinesterase and amplify chologernic transmission

Answer 16

• neurostigmine enzyme
• SARAN gas
• VX

Question 17

What drugs block the release of Ach

Answer 17

• black widow spider venom (a-latrotoxin) - causes random release of Ach causing muscle spasms
• botulinum toxin

Question 18

What is botulium toxin used to treat clinically

Answer 18

• salivary drooling, achalasia, cosmetic reasons, biological warfare, blepharospasm

Question 19

What are examples of neurotransmitters that inhibiit neurotransmitter release in receptors

Answer 19

• Ach musc inhibits Ach ent
• Ach nicht inhibits Ach
• ATP- adenosine inhibits A1 receptor
• morphine opioids inhibit opioide receptors- leads to constipation (messes with gut function)
• NA inhibit a- adrenoreceptors SYMATHETIC CROSS INHIBITION

Question 20

What agonists bind to muscarinic receptors and mimic effect of parasympathetic nerve stimulation

Answer 20

• Ach
• carbachol
• muscarine
• pilocarpine
• oxytremorine
  all mimic effects of parasympathetic stimulation

Question 21

What do we use for Glucoma treatment of the eye

Answer 21

• pilocarpine - drains fluid and reduces eye pressure

- misuse as mushroom poisoning and is toxic

Question 22

Why do we never use muscarinics agonist systemically and always locally or tropically

Answer 22

• lots of musc receptors in body
• effect = decreased heart rate
• smooth muscle contracts, vascular dialates
• exocrine gland- sweating, salivation, bronchial secretion, lacrimation

Question 23

How does atropine cure side effects of acetylcholine antagonists such as niostigmine?

Answer 23

• used in surgery, reverses amplified parasympathetic transmission of niostigmine after being given to reverse paralysis
• stops some symptoms of. chemical weapons such as SARIN

Question 24

How does hyoscine cure motion sickness

Answer 24

ANTIMUSCARINIC

• nausea and sickness
• inhibits chologernic transmission in gut- less nausea and sickness
• muscarinic receptors also in brain so works in CNS