21 Autonomic Nervous System

Question 1

How drugs enter eye

Answer 1

Fat soluble form passes epi

Requilibrates as both forms

Passes through stroma as ionised form

Fat soluble passes through endo

Requilibrates as both form and ionic form differed through AQ to tissues

Question 2

Sympathetic Nervous system pathway

Answer 2

Preganglionic release of Ach at Ach Nic receptor

Noradrenaline release on a adrenergic receptor

Dilator contracts

Question 3

Agonist and antagonist of noradrenaline

Answer 3

Agonist phenylpherine

Antagonist thymoxamine

Question 4

Parasympathetic system pathway

Answer 4

Ach release on Ach Nic receptors

Ache release on Ach musc receptors

Sphincter contracts

Question 5

Agonist and antagonist of Ach on Ach musc receptor

Answer 5

Agonist pilocarpine

Antagonist atropine

Question 6

Somatic system pathway

Answer 6

Ach release on Ach Nic receptor

Skeletal muscle contracts

Curare is antagonist

Question 7

Adrenergic receptors types

Answer 7

Alpha 1 contract SM in BV, on dilator

Alpha 2 located presynaptically in terminals of SNS and inhibits transmitter release

Beta 1 heart and adipose

Bega 2 lung liver and vascular SM

Question 8

What’s denervation super sensitivity

Answer 8

Death of a nerve causing change in receptor activity in post synaptic membrane

Proliferates receptors, loss mechanisms for transmitter removal and increased responsiveness

SO tissues over response to drugs acting directly on receptors

Question 9

What’s Adies Tonic pupil

Answer 9

Parasympathetic dysfunction so can’t constrict to light

May be denervation if post ganglion fibres to sphincter and ciliary muscles giving cholinergic hypersensitivity so test with 0.125% pilocarpine

Question 10

What’s tolerance/tachyphylaxis

Answer 10

Chronic use of direct agonist drugs causing receptor down regulation

Leads to lack of effect and due to receptors being less available and so a higher conc of drug needed to create effect

Question 11

Systemic effects of adrenergic agonist

Answer 11

Fight or flight

• increase BP thru a1 agonist
• HR increase
• bronchioles dilate

Question 12

Ocular signs of adrenergic agonist

Answer 12

Mullers muscle contract

Vasoconstriction

Pupil dilated

IOP lowered

Question 13

Effects of muscarinic antagonism

Answer 13

Hot as hare
Red as beet
Dry as bone
Blind as baT
Mad as hatter

Question 14

What’s dapiprozole

Answer 14

Reduces pupil diameter after my static exam by blocking alpha1 receptors