Introduction to principles Flashcards
Define affinity
Affinity = strength of interaction between a drug and it’s target
define efficacy
efficacy = the ability of a drug, once bound to activate the receptor by a conformational change
define the term ‘drug’
chemically defined small molecules which produce a physiological effect when administered
enzymes, transporters, ion channels and receptors are all examples of sites of action for drugs. give a specific example for:
- drugs acting at enzymes being either substrates or inhibitors
Drugs acting as substrates at enzymes:
e.g. dopamine neurotransmission - L-DOPA
supplying more L-DOPA to the the enzyme DOPA decarboxylase will produce more dopamine (desired effect) since L-DOPA is a substrate for that enzyme
Drugs acting as inhibitors at enzymes:
E.g. inhibiting acetylcholinesterase - donepezil, neostigme
acetylcholinesterase is responsible for breaking down acetylcholine in cholinergic synapses, by inhibiting this enzyme, you prevent he reuptake of ACh, prolonging the time ACh is active
enzymes, transporters, ion channels and receptors are all examples of sites of action for drugs. give a specific example for:
- drugs acting at transporters
E.g. Cocaine - inhibiting the reuptake of dopamine into the presynaptic terminal
cocaine binds to the dopamine transporter on the presynaptic terminal preventing the re-uptake of dopamine, prolonging its action and therefore enhancing the response
enzymes, transporters, ion channels and receptors are all examples of sites of action for drugs. give a specific example for:
- drugs acting at ion channels
E.g. local anaesthetics - acting at the sodium ion channel
Local anaesthetics such as lidocaine block the ion channel pore, preventing ions from getting through when the channel is opened by an action potential, this blocking stops the action potential and hence the transmission of pain signals through the fibres
enzymes, transporters, ion channels and receptors are all examples of sites of action for drugs.
what are the two types of drugs that act at receptors
there are two types of drugs that act at receptors:
- agonists - reproduce the effects of the endogenous messenger
- antagonists - block the effects of the endogenous messenger
what are the four major superfamilies of receptors
- Ligand Gated Ion Channels
- G protein Coupled Receptors
- Catalytic Receptors
- Nuclear Receptors
what type of receptor is shown in this image?
ligand-gated ion channel
what type of receptor is shown in the image below?
G-protein coupled receptor
what type of receptor is shown in the image below
catalytic receptor
what type of receptor is shown in the image below?
nuclear receptors
what nervous system of the ANS:
controls the fight or flight response?
controls the rest and digest response?
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what are the two types of neurons used in the sympathetic and parasympathetic pathways?
and which one projects from the CNS and which one innervates the target tissue
- pre ganglionic
- postganglionic
in the sympathetic nervous system which neurons are long and which are short
out of pre and postganglionic
preganglionic - short
postganglionic - long
which columns out of the left and right show the effects on the body of the different nervous systems
parasympathetic and sympathetic
