9.6 effects of drugs on the nervous system

Question 1

what are the ways that drugs increase the response in the synapse?

Answer 1

• increases the amount of neurotransmitter synthesised
• increases the release of neurotransmitter from the vesicles at the presynaptic membrane
• binds to post-synaptic receptors and activates them or increases the effect of the normal neurotransmitter
• prevents the degradation of neurotransmitter by enzymes OR prevents reuptake into presynaptic knob

Question 2

what are the ways that drugs decrease the response in the synapse?

Answer 2

• block the synthesising of neurotransmitter
• causes neurotransmitter to leak from vesicles and be destroyed by enzymes
• prevents the release of neurotransmitters from vesicles
• blocks the receptors and prevents neurotrasmitters binding

Question 3

how does nicotine affect our bodies?

Answer 3

• mimics the effects of acetylcholine and binds to specific acetylcholine receptors in the post-synaptic membrane known as nicotine receptors
• triggers an action potential in the post synaptic neurone but cannot again for some time
• causes raised heart rate and blood pressure
• triggers the release of dopamine

Question 4

how does lidocain affect our bodies?

Answer 4

• drug used as a local anasthetic
• commonly used in dentists
• block voltage gated sodium channels preventing the production of an action potential in sensory nerves so you can’t feel any pain

Question 5

how does cobra venom affect our bodies?

Answer 5

• toxic and often fatal
• binds reversibly to acetylcholine receptors in post -synaptic membrane and neurotransmitter junctions
• prevents the transmission of impulses across synapses inclusing between motor neurones and muscles
• muscles cannot contract and person becomes paralysed
• affects breathing muscles and causes death