78 Questions
Which receptor subtype is primarily responsible for the vasodilation due to NO release from the vascular endothelium?
M3
Which drug is used for bronchial provocation testing and has no nicotinic effect?
Metacholine
Which parasympathomimetic alkaloid has the greatest effect on the sweat glands and is used for open-angle glaucoma?
Pilocarpine
Which cholinomimetic drug causes miosis and accommodation spasm in local application to the eye, and increases drainage from the Schlemm channel?
Pilocarpine
Which cholinomimetic drug has an M1-mediated effect on learning and memory at the CNS, but the effect is short-lived?
Arekolin
Which receptor subtype is primarily responsible for the contraction of bronchial smooth muscles?
M3
Which cholinomimetic drug is used in eye surgery to cause miosis?
Acetylcholine
Which cholinomimetic drug selectively stimulates muscarinic receptors in the striatum of the brain, producing parkinsonian-like symptoms?
Oxotremorine
Which cholinomimetic drug has a high affinity for M3 receptors in the lacrimal and salivary gland epithelium, and has a sialogog effect?
Sevmelin
Which cholinomimetic drug is hardly used as a medicine, breaks down quickly in plasma, and is ineffective when used orally?
Acetylcholine
Which anticholinesterase drug is a reversible inhibitor and contains a quaternary amine group?
Neostigmine
Which drug is used for the treatment of symptoms of dry mouth and eyes in patients with Sjogren's syndrome?
Pilocarpine
Which type of nerve terminates in the neuromuscular junction and has a nicotinic receptor?
Cholinergic nerve
Which division of the autonomic nervous system is responsible for 'rest' and 'digest' functions?
Parasympathetic
Which spinal nerves are associated with the parasympathetic division of the autonomic nervous system?
CS 3,7,9,10 and S2-4
Which division of the autonomic nervous system is responsible for 'fight' or 'flight' responses?
Sympathetic
Which type of receptors are the nicotinic receptors at the neuromuscular junctions of the skeletal muscles?
Skeletal muscle type NM receptors
What is the enzyme responsible for the breakdown of acetylcholine in the synapse?
Acetylcholinesterase (AChE)
Which type of cholinergic receptors are G protein-coupled?
Muscarinic receptors
In which locations are M2 receptors commonly found?
Heart and presynaptic autoreceptors
Which drugs are classified as cholinesterase inhibitors?
Anticholinesterases
What is the neurotransmitter responsible for impulse transmission at cholinergic synapses or junctions?
Acetylcholine
Which neurons of the autonomous nervous system are exceptions to being cholinergic?
Sympathetic neurons innervating eccrine sweat glands
Which receptors are selectively urbanized by the Na+ ion channel?
Nicotinic receptors
What is the main action of M3 receptors when activated?
Increases gland secretion and promotes smooth muscle contraction
Which type of cholinergic receptors are found in pathways related to learning and memory in the brain?
M1 receptors
Which drugs mimic the effects of parasympathetic stimulation by activating muscarinic receptors in the effector cells?
Parasympathomimetic drugs (muscarinic agonists)
What are the drugs that directly or indirectly activate muscarinic and/or nicotinic cholinergic receptors and mimic the action of acetylcholine in target cells?
Cholinomimetic drugs
Which type of nerve terminates in the neuromuscular junction and has a nicotinic receptor?
Motor nerve
Which cholinomimetic drug is hardly used as a medicine, breaks down quickly in plasma, and is ineffective when used orally?
Edrophonium
Which receptor subtype is primarily responsible for the contraction of bronchial smooth muscles?
M3 receptor
Where are the M2 receptors commonly found?
Heart
Which of the following is a clinical use of edrophonium?
Diagnosis of myasthenia gravis
Which drug is a reversible inhibitor and is used in mild and moderate Alzheimer's disease?
Rivastigmine
Which organophosphate is considered the most toxic and is used as a chemical warfare poison?
Sarin
Which drug is used in the treatment of postoperative paralytic ileus and bladder atony?
Neostigmine
What is the main cause of death in poisoning with organophosphate insecticides?
Respiratory paralysis
Which drug is used in the therapy for open-angle glaucoma?
Pilocarpine
Which type of cholinergic receptors are primarily responsible for the vasodilation due to NO release from the vascular endothelium?
M3 receptors
Which drug is a reversible inhibitor and contains a quaternary amine group, thereby not affecting the CNS?
Neostigmine
Which receptor subtype is primarily responsible for the contraction of bronchial smooth muscles?
M3 receptors
Which drug is an irreversible inhibitor and is used as a treatment for symptoms of dry mouth and eyes in patients with Sjogren's syndrome?
Pilocarpine
Which drug is used for bronchial provocation testing and has no nicotinic effect?
Methacholine
Which drug is used for the treatment of Alzheimer's disease and has a short-lived effect on learning and memory at the CNS?
Donepezil
Which type of nerve is an exception to being cholinergic?
Sympathetic neurons innervating skeletal muscle vessels
Which type of receptors primarily responsible for the contraction of bronchial smooth muscles?
M3 receptors
Which cholinomimetic drug is used for open-angle glaucoma and has the greatest effect on the sweat glands?
Pilocarpine
Which receptor subtype is primarily responsible for vasodilation due to NO release from the vascular endothelium?
M3 receptors
Which cholinomimetic drug causes miosis and accommodation spasm in local application to the eye, and increases drainage from the Schlemm channel?
Pilocarpine
Which drug is used in eye surgery to cause miosis?
Pilocarpine
Which cholinomimetic drug has a high affinity for M3 receptors in the lacrimal and salivary gland epithelium, and has a sialogog effect?
Pilocarpine
Which anticholinesterase drug is a reversible inhibitor and contains a quaternary amine group?
Neostigmine
Which type of receptors are the nicotinic receptors at the neuromuscular junctions of the skeletal muscles?
Nicotinic receptors
Which drug is used for bronchial provocation testing and has no nicotinic effect?
Ipratropium
Which drug directly activates muscarinic receptors, producing effects similar to those of parasympathetic nerve stimulation?
Bethanechol
Which receptor subtype is primarily responsible for the sialogog effect in the salivary glands?
M3 receptors
Which drug is a short-acting agent used for diagnosing myasthenia gravis and differentiating myasthenic and cholinergic crises?
Edrophonium
Which type of inhibitors are tabun, sarin, and soman, used as nerve gas agents?
Irreversible inhibitors
Which condition is a contraindication for cholinomimetic drugs?
Asthma
Which drugs are used in mild and moderate Alzheimer's disease?
Rivastigmine, donepezil, galantamine
What is the primary clinical use of neostigmine, pyridostigmine, ambenonium, and distigmine?
Myasthenia gravis
What are the clinical uses of cholinomimetic drugs?
Finishing the action of neuromuscular blocking drugs
What is the maximum toxic effect of organophosphate insecticides?
Absorption via the lungs
What are the symptoms of cholinergic crisis caused by organophosphate insecticides?
All of the above
What is the therapy for organophosphate poisoning?
All of the above
What is the treatment for carbamate insecticide poisoning?
Atropine
Which type of cholinergic receptors are ion channel receptors?
Nicotinic receptors
Which division of the autonomic nervous system do cholinergic neurons primarily belong to?
Parasympathetic division
Which type of cholinomimetic drugs directly activate muscarinic receptors?
Parasympathomimetic drugs
Which receptors are selectively blocked or activated by specific substances at different locations such as neuromuscular junctions and autonomic ganglia?
Nicotinic receptors
Which enzyme do anticholinesterases inhibit, leading to the accumulation of acetylcholine at cholinergic junctions?
Acetylcholinesterase
Which type of cholinergic receptors include M1, M2, and M3 subtypes?
Muscarinic receptors
Which drugs replicate the effects of parasympathetic stimulation by activating muscarinic receptors in effector cells?
Cholinomimetic drugs
Which neurons are exceptions to being cholinergic in the sympathetic division of the autonomic nervous system?
Neurons innervating sweat glands
Which drugs directly or indirectly activate muscarinic and/or nicotinic cholinergic receptors?
Cholinesterase inhibitors
Which receptors are primarily responsible for the vasodilation due to NO release from the vascular endothelium?
M3 receptors
Which receptors are primarily responsible for the contraction of bronchial smooth muscles?
M3 receptors
Which drugs are used for open-angle glaucoma and have the greatest effect on the sweat glands?
Cholinomimetic drugs
Study Notes
Cholinergic Synapses and Receptors: Key Points
- Acetylcholine is the neurotransmitter responsible for impulse transmission at cholinergic synapses/junctions.
- Cholinergic neurons are present in the first-line neurons of the sympathetic and parasympathetic systems.
- Exceptions include sympathetic neurons innervating eccrine sweat glands and some innervating skeletal muscle vessels.
- Cholinergic receptors include nicotinic receptors, which are ion channel receptors, and muscarinic receptors, which are G protein-coupled receptors.
- The synthesis, storage, release, action, and inactivation of acetylcholine follow a specific process at cholinergic synapses.
- Nicotinic receptors at different locations, such as the neuromuscular junctions and autonomic ganglia, are of distinct types and can be selectively blocked or activated by specific substances.
- Muscarinic receptors include M1, M2, and M3 types, and their locations and effects vary in different tissues and organs.
- Cholinomimetic drugs directly or indirectly activate muscarinic and/or nicotinic cholinergic receptors, mimicking the action of acetylcholine in target cells.
- Parasympathomimetic drugs directly activate muscarinic receptors, producing effects similar to those of parasympathetic nerve stimulation.
- Anticholinesterases inhibit acetylcholinesterase, causing acetylcholine to accumulate at cholinergic junctions, leading to parasympathomimetic and nicotinic effects.
- Cholinomimetic drugs replicate the effects of parasympathetic stimulation by activating muscarinic receptors in effector cells.
- Overall, the text provides a comprehensive overview of the neurotransmitter acetylcholine, cholinergic synapses, receptors, and the pharmacological implications of cholinomimetic drugs.
Cholinergic Synapses and Receptors: Key Points
- Acetylcholine is the neurotransmitter responsible for impulse transmission at cholinergic synapses/junctions.
- Cholinergic neurons are present in the first-line neurons of the sympathetic and parasympathetic systems.
- Exceptions include sympathetic neurons innervating eccrine sweat glands and some innervating skeletal muscle vessels.
- Cholinergic receptors include nicotinic receptors, which are ion channel receptors, and muscarinic receptors, which are G protein-coupled receptors.
- The synthesis, storage, release, action, and inactivation of acetylcholine follow a specific process at cholinergic synapses.
- Nicotinic receptors at different locations, such as the neuromuscular junctions and autonomic ganglia, are of distinct types and can be selectively blocked or activated by specific substances.
- Muscarinic receptors include M1, M2, and M3 types, and their locations and effects vary in different tissues and organs.
- Cholinomimetic drugs directly or indirectly activate muscarinic and/or nicotinic cholinergic receptors, mimicking the action of acetylcholine in target cells.
- Parasympathomimetic drugs directly activate muscarinic receptors, producing effects similar to those of parasympathetic nerve stimulation.
- Anticholinesterases inhibit acetylcholinesterase, causing acetylcholine to accumulate at cholinergic junctions, leading to parasympathomimetic and nicotinic effects.
- Cholinomimetic drugs replicate the effects of parasympathetic stimulation by activating muscarinic receptors in effector cells.
- Overall, the text provides a comprehensive overview of the neurotransmitter acetylcholine, cholinergic synapses, receptors, and the pharmacological implications of cholinomimetic drugs.
Test your knowledge about the key points related to cholinergic synapses and receptors, including acetylcholine as the neurotransmitter, nicotinic and muscarinic receptors, cholinomimetic drugs, parasympathomimetic drugs, and anticholinesterases.
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