At autonomic ganglia and after post ganlionic parasympathetic fibres. With few exceptions
ACh (acetylcholine) binds to receptors at the NMJ (neuromuscular junction) to induce contraction of muscle.
Competes with ACh at the nerve receptors and results in under stimulatin of the receptors
myasthenia gravis
General sensory receptors such as light touch and temperature receptors are located over the entire surface of the body. There are no specific areas where these receptors are located.
the depolarization of the muscle cell. This occurs when the ACh receptors open, allowing sodium ions to enter the muscle cell, which leads to the generation of an action potential. The action potential then propagates along the muscle cell, initiating contraction.
Nicotinic receptors are closed until ACh molecules bind to the receptor proteins.
ACh (acetylcholine) binds to receptors at the NMJ (neuromuscular junction) to induce contraction of muscle.
ACH receptors can be defined as an integral membrane protein that responds to the binding of acetylcholine, a neuoyansmitter. Two example are nicotinic acetyl line receptors and muscarinic acetylcholine receptors. .
AChE destroys the ACh and they are removed from the membrane receptors.
ACh esterase, which breaks ACh down into an acetyl group and a choline group. This is then taken up by the neurone and some is reformed into ACh.
Neostigmine is a competitive irreversible inhibitor of Acetylcholinesterase (AChE), an enzyme responsible for breaking down acetylcholine (ACh). Myasthenia gravis is caused by the body producing too little ACh receptors. As stimulating the ACh receptors is needed for nervous transmission, the nerve signals cannot be transmitted causing muscle weakness and fatigue. Neostigmine is hence used to inhibit AChE so that less ACh gets broken down. This leads to more ACh binding to the ACh receptors causing muscular contraction.
they stimulate the action of ACh at post ganglionic muscarinic receptors.
Competes with ACh at the nerve receptors and results in under stimulatin of the receptors.
Competes with ACh at the nerve receptors and results in under stimulatin of the receptors
It doesn't atropine only acts on muscarinic receptors (it's a competitive antagonist here for ACh), but histamine acts on different receptors (histamine receptors). There is no direct interaction between atropine and histamine receptors
myasthenia gravis
Preganglionic fibers for the SNS release ACh; so a drug that stimulates ACh receptors would stimulate the postganglionic fibers of sypathetic nerves, resulting in increased sympathetic activity