PHARM ANS Adrenergic & Cholinergic Flashcards
Classify pre-ganglionic & post-ganglionic nerves as myelinated or unmyelinated.
Pre-ganglionic nerves (myelinated)
Post-ganglionic nerves (unmyelinated).
Classifications of cholinoreceptors.
ACh receptors.
N (SNS/PSNS) & M (PSNS).
What must be considered for those drugs targeting N receptors and why?
Tone. No way to differentiate between targeted ANS ganglia of PSNS & SNS divisions.
Classifications of adrenoreceptors.
NA/A receptors.
a (more likely to be acted upon by NA) & B (more likely to be acted upon by A).
Tissue location of a1A receptors.
Heart, liver, brain & genitourinary tract.
Nicotinic agonists/antagonist response.
Stimulate PSNS/SNS depending on pt tone.
Muscarinic agonist response.
Stimulate PSNS.
Muscarinic antagonist response.
Stimulate SNS.
Levodopa & carbidopa action.
Increase noradrenaline levels (as L-dopa is a precursor). Agonise SNS – thus often administered w carbidopa, which inhibits DDC enzyme function. However, carbidopa cannot cross the BBB. Thus, if co-administered, L-dopa crosses BBB to combat symptoms of Parkinson’s disease, whilst carbidopa prevents SNS antagonisation and associated side effects in the PNS (used in treatment of Parkinson’s disease).
Clonidine action.
a2 agonist – activates receptors on pre-synaptic neuron to inhibit noradrenaline release -> SNS deactivation.
Cocaine action.
Blocks active re-uptake of noradrenaline at the NET of the pre-synaptic nerve, to increase noradrenaline -> SNS activation.
Neostigmine action.
Binds to AChE and inhibits function to increase conc. ACh (used in treatment of MG).
Botulinum toxin action.
Prevents exocytosis of ACh to decrease conc. ACh -> permanent muscle relaxation (e.g., botox).
Which part of the brain is mainly responsible for ANS control?
Hypothalamus.
Gate mechanisms involved with N & M receptors.
nicotinic = ligand gated, muscarinic = g protein coupled receptors
