Podcast
Questions and Answers
What is the primary focus of the lectures based on the information provided?
What is the primary focus of the lectures based on the information provided?
- Detailing surgical procedures involving the nervous system.
- Listing all known neurotransmitters and their exact functions.
- Explaining neurotransmission and how drugs can modify it. (correct)
- Describing the anatomy of the brain.
Neurotransmission is not a target for therapeutic drugs.
Neurotransmission is not a target for therapeutic drugs.
False (B)
Which of the following is a primary component of a neuron?
Which of the following is a primary component of a neuron?
- Cell body (correct)
- Salivary gland
- Bronchi
- Abdominal blood vessel
Local anesthetics inhibit nerve conduction by blocking ______ channels.
Local anesthetics inhibit nerve conduction by blocking ______ channels.
Match the following neurotransmitters with their associated nervous system component:
Match the following neurotransmitters with their associated nervous system component:
Which neurotransmitter is primarily associated with the sympathetic nervous system?
Which neurotransmitter is primarily associated with the sympathetic nervous system?
The ganglia of the parasympathetic nervous system are typically located far from the target tissues.
The ganglia of the parasympathetic nervous system are typically located far from the target tissues.
The sympathetic nervous system emanates from the ______ segments of the spinal cord.
The sympathetic nervous system emanates from the ______ segments of the spinal cord.
Which outflow is associated with the parasympathetic nervous system?
Which outflow is associated with the parasympathetic nervous system?
The sympathetic ganglia are typically close to the spinal cord in the paravertebral chain.
The sympathetic ganglia are typically close to the spinal cord in the paravertebral chain.
What triggers the release of neurotransmitters at the neuroeffector junction?
What triggers the release of neurotransmitters at the neuroeffector junction?
What ion influx directly triggers exocytosis of neurotransmitters at the nerve terminal?
What ion influx directly triggers exocytosis of neurotransmitters at the nerve terminal?
L-DOPA is used therapeutically to increase ______ levels in the brains of patients with Parkinson's disease.
L-DOPA is used therapeutically to increase ______ levels in the brains of patients with Parkinson's disease.
Inhibiting the termination of neurotransmission generally decreases the effect of the neurotransmitter.
Inhibiting the termination of neurotransmission generally decreases the effect of the neurotransmitter.
Match these drugs with their primary mechanism of action on neurotransmitters:
Match these drugs with their primary mechanism of action on neurotransmitters:
What is the primary action of an agonist on a receptor?
What is the primary action of an agonist on a receptor?
An antagonist has affinity and efficacy at a receptor.
An antagonist has affinity and efficacy at a receptor.
What are the two main characteristics of an agonist?
What are the two main characteristics of an agonist?
The drug ______ acts on a site different from the GABA binding site to enhance the effects of GABA.
The drug ______ acts on a site different from the GABA binding site to enhance the effects of GABA.
Match the following receptor agonists with their therapeutic uses:
Match the following receptor agonists with their therapeutic uses:
Which of the following drugs is a receptor antagonist used as a pre-medication?
Which of the following drugs is a receptor antagonist used as a pre-medication?
Sildenafil (Viagra) directly enhances the production of nitric oxide in erectile tissue.
Sildenafil (Viagra) directly enhances the production of nitric oxide in erectile tissue.
Which of the following is NOT a typical site of drug action in neurotransmission?
Which of the following is NOT a typical site of drug action in neurotransmission?
What is the function of the enzyme acetylcholinesterase?
What is the function of the enzyme acetylcholinesterase?
The use of guanethidine can ______ the terminal depolarization.
The use of guanethidine can ______ the terminal depolarization.
Which of the following drugs inhibits vesicle fusion?
Which of the following drugs inhibits vesicle fusion?
Clonidine is an α₂ antagonist that increases noradrenaline release.
Clonidine is an α₂ antagonist that increases noradrenaline release.
Match the following site of drug action in neurotransmission with the drug or process:
Match the following site of drug action in neurotransmission with the drug or process:
Which of the following is the direct result of the action potential at the neuroeffector junction?
Which of the following is the direct result of the action potential at the neuroeffector junction?
The effect of a neurotransmitter is solely determined by its concentration in the synaptic cleft.
The effect of a neurotransmitter is solely determined by its concentration in the synaptic cleft.
What geometry allows the diffusion of the neurotransmitter?
What geometry allows the diffusion of the neurotransmitter?
[Blank] is used to reverse relaxation in surgery.
[Blank] is used to reverse relaxation in surgery.
What is the function of benzodiazepine tranquillisers?
What is the function of benzodiazepine tranquillisers?
Receptors are not an important consideration in developing drugs with reduced side effects.
Receptors are not an important consideration in developing drugs with reduced side effects.
What effect does AMPT have on NA?
What effect does AMPT have on NA?
Botulinum inhibits ______ fusion.
Botulinum inhibits ______ fusion.
Match the following sites of drug action with their corresponding effect:
Match the following sites of drug action with their corresponding effect:
Which of the following is the primary reason why the synapse is an important target for drug action?
Which of the following is the primary reason why the synapse is an important target for drug action?
Drugs that affect neurotransmitter synthesis always increase neurotransmitter concentrations.
Drugs that affect neurotransmitter synthesis always increase neurotransmitter concentrations.
Name three main routes of the sympathetic nerves.
Name three main routes of the sympathetic nerves.
An inhibitory effect on ____ _______ inhibits dopamine
An inhibitory effect on ____ _______ inhibits dopamine
Which of the following best describes the aim of the lectures?
Which of the following best describes the aim of the lectures?
Local anesthetics inhibit nerve conduction by blocking potassium channels.
Local anesthetics inhibit nerve conduction by blocking potassium channels.
Which neurotransmitter is primarily associated with sympathetic terminals?
Which neurotransmitter is primarily associated with sympathetic terminals?
Where are the ganglia typically located in the sympathetic nervous system?
Where are the ganglia typically located in the sympathetic nervous system?
In the parasympathetic nervous system, the _ outflow consists of cranial and sacral components.
In the parasympathetic nervous system, the _ outflow consists of cranial and sacral components.
Which of the following directly triggers the release of neurotransmitters at the neuroeffector junction?
Which of the following directly triggers the release of neurotransmitters at the neuroeffector junction?
How does L-DOPA act therapeutically in Parkinson's disease?
How does L-DOPA act therapeutically in Parkinson's disease?
Guanethidine inhibits action potential in nerve terminals. True or False?
Guanethidine inhibits action potential in nerve terminals. True or False?
______ such as fluoxetine, inhibit 5-HT uptake.
______ such as fluoxetine, inhibit 5-HT uptake.
What is the key difference between an agonist and an antagonist in terms of receptor action?
What is the key difference between an agonist and an antagonist in terms of receptor action?
Flashcards
Neurotransmission
Neurotransmission
The process by which neurons communicate with each other or with target tissues.
Neuron
Neuron
A nerve cell that transmits electrical impulses.
Dendrites
Dendrites
Branchlike extensions of a neuron that receive signals from other neurons.
Axon
Axon
Signup and view all the flashcards
Nerve terminal
Nerve terminal
Signup and view all the flashcards
Neurotransmitter (NT)
Neurotransmitter (NT)
Signup and view all the flashcards
Ganglion
Ganglion
Signup and view all the flashcards
Sympathetic Nerves
Sympathetic Nerves
Signup and view all the flashcards
Parasympathetic Nerves
Parasympathetic Nerves
Signup and view all the flashcards
Neuromuscular Junction (NMJ)
Neuromuscular Junction (NMJ)
Signup and view all the flashcards
Neurotransmitters (examples)
Neurotransmitters (examples)
Signup and view all the flashcards
Craniosacral outflow
Craniosacral outflow
Signup and view all the flashcards
Neuroeffector Junction
Neuroeffector Junction
Signup and view all the flashcards
Action Potential
Action Potential
Signup and view all the flashcards
Depolarization
Depolarization
Signup and view all the flashcards
Voltage-Operated Calcium Channel
Voltage-Operated Calcium Channel
Signup and view all the flashcards
Exocytosis
Exocytosis
Signup and view all the flashcards
Agonist
Agonist
Signup and view all the flashcards
Presynaptic Autoinhibitory Receptors
Presynaptic Autoinhibitory Receptors
Signup and view all the flashcards
Antagonist
Antagonist
Signup and view all the flashcards
Reuptake
Reuptake
Signup and view all the flashcards
Sites of Drug Action
Sites of Drug Action
Signup and view all the flashcards
Study Notes
- The lectures aim to describe neurotransmission and its modification by drugs.
- Students should understand why neurotransmission is a target for therapeutic drug development.
The Neuron
- The neuron is a nerve cell that transmits electrical signals.
- NT stands for neurotransmitter.
- The neuron consists of the cell body, axon, and dendrites.
- The cell body contains the nucleus and other organelles.
- The axon is a long, slender projection that conducts electrical impulses away from the cell body.
- Dendrites are branched extensions that receive signals from other neurons.
- The nerve terminal is the end of the axon, where neurotransmitters are released.
- Local anesthetics inhibit nerve conduction by blocking sodium channels.
Sympathetic and Parasympathetic Nerves
- Sympathetic nerves originate from the brain and spinal cord, and connect to tissue via a ganglion.
- Parasympathetic nerves also originate from the brain and spinal cord, connecting to tissue via a ganglion.
- Motor nerves connect the spinal cord directly to the neuromuscular junction (NMJ) in skeletal muscle.
Neurotransmitters
- Noradrenaline (NA) is found at sympathetic terminals.
- Acetylcholine (ACh) is located at parasympathetic terminals, ganglia, and the NMJ.
- Dopamine (DA) and Serotonin (5-HT) are found in parts of the CNS.
- Nitric oxide (NO) can be found in less common places.
Anatomy of the Sympathetic Nervous System
- The sympathetic nervous system emanates from the thoracolumbar segments of the spinal cord.
- Ganglia are typically close to the spinal cord in the paravertebral chain.
Anatomy of the Parasympathetic Nervous System
- Craniosacral outflow includes cranial nerves (oculomotor, facial, glossopharyngeal, vagal) and sacral nerves (nervi erigentes).
- Ganglia are located close to or inside target tissues.
The Neuroeffector Junction (Terminal Region)
- Action potential arrives at the nerve terminal.
- Depolarization occurs.
- Voltage-operated calcium channels open, allowing calcium ions (Ca) to enter.
- NT is released via Exocytosis.
- Neurotransmitters (NT) are released.
- Presynaptic autoinhibitory agonism occurs
- Postsynaptic agonism occurs.
Synthesis and Storage of Transmitter
- Precursor uptake is inhibited by hemicholinium for Acetylcholine (ACh).
- L-DOPA increases dopamine levels in Parkinson's patients.
- The enzyme cascade is inhibited by AMPT for Noradrenaline (NA).
- Storage is inhibited by reserpine for Noradrenaline (NA).
Release of Transmitter
- Terminal depolarization is inhibited by guanethidine with Noradrenaline (NA).
- Conotoxin inhibits calcium channels.
- Vesicle fusion is inhibited by Botulinum for Acetylcholine (ACh).
- Amphetamine and guanethidine displace Noradrenaline.
- Clonidine, an α2 agonist, inhibits the release of Noradrenaline via presynaptic receptors.
Termination of Neurotransmission
- Diffusion occurs at the geometry of the cleft.
- Reuptake is inhibited by cocaine for Noradrenaline (NA) and fluoxetine for Serotonin (5-HT).
- Tricyclic antidepressants inhibit NA uptake, while fluoxetine (Prozac) inhibits 5-HT uptake.
- The breakdown of neurotransmitters is modified by inhibiting enzymes such as neostigmine/ACh.
- Anticholinesterases reverse muscle relaxation in surgery.
Agonist and Antagonist Action on Receptors
- Agonists have affinity and efficacy, stimulate receptors, and mimic transmitters.
- Antagonists have affinity but no efficacy, block the binding site, and inhibit agonist action.
Receptor Agonists with Major Therapeutic Applications
- Salbutamol is a beta 2 noradrenaline receptor agonist used for asthma.
- Phenylephrine is an alpha-1 noradrenaline receptor agonist used as a decongestant.
- Bromocriptine is a dopamine D2 receptor agonist used for Parkinson's disease.
- Morphine is an enkephalin receptor agonist used for pain relief.
- Diazepam is a GABA/A receptor agonist used for anxiety.
- Diazepam enhances the effects of GABA by acting on a site different from the GABA binding site.
Receptor Antagonists with Major Therapeutic Applications
- Prazosin is an alpha-1 noradrenaline receptor antagonist used to reduce blood pressure.
- Propranolol is a beta noradrenaline receptor antagonist used to reduce blood pressure.
- Atracurium is an acetylcholine nicotinic receptor antagonist used as a muscle relaxant.
- Atropine is an acetylcholine muscarinic receptor antagonist used as a pre-medication.
- Trifluoperazine is a dopamine D2, receptor antagonist used as an antipsychotic.
Drugs Affecting the Neuroeffector Response
- Benzodiazepine tranquilizers bind to the GABA receptor/Cl ion channel complex
- This enhances channel opening and potentiates the inhibitory effects of GABA.
- Sildenafil (Viagra) inhibits the breakdown of cyclic GMP, a second messenger substance produced by nitric oxide in erectile tissue.
Summary of Drug Action Sites
- Synthesis
- Storage
- Release
- Receptors
- Cessation: Reuptake, Enzyme, Autoinhibition
Conclusion
- The synapse is an important site for drug action.
- Because it’s the site of neurotransmission
- It’s the site where the transmitter is synthesised, stored, and released
- It’s a major location for receptors and target for agonists or antagonists
- Receptors offer the best chance of producing drugs with a high degree of selectivity and reduced side effect profile
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
