The aim of the experiment was to investigate the initiation of the peristalsis reflex in a piece of guinea pig ileum through the stimulation of the stretch receptors, and subsequently demonstrate that the peristalsis reflex is neuronal in origin and not just a property of the muscle itself. Several drugs including lignocaine, atropine, hexamethonium, and nicardipine were induced to a piece of guinea pig ileum under a standard hydrostatic pressure of 5.0 cm/H2O, and hence the effects determined that the peristalsis reflex is dependent on neuronal activity. The results of the experiment confirmed with the hypothesis, which stated that lignocaine, atropine, and hexamethonium would reduce the contractile response of the smooth muscle, yet nicardipine
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Hence, due to the blocking properties of lignocaine, it prevents the depolarization of the postsynaptic neuron, and averts the initiation of an action potential (Sheu and Lederer, 1985). The effects of lignocaine on the intestinal smooth muscle are described to be concentration-dependent contractures (F A., 1986). Thus, in the experiment, as the amplitude of contraction was diminished, it demonstrated an anesthetic function of lignocaine on nociceptors (van den Broek et al., 2011). Another drug that was applied to the ileum tissue in the organ bath of Tyrode’s solution (37°C) was atropine, which exhibits a competitive antagonistic property, and has an antagonizing effect on the muscarinic acetylcholine receptors (Araki et al., 1976). Atropine is a non-specific anti-cholinergic antagonist drug that functions as a blockage of neuronal nicotinic acetylcholine receptors (nAChRs), and furthermore blocks the nicotine-induced responses (Cuthbert, 1963). Functioning as an antagonist, atropine binds to the M2 and M3 with high affinity and causes the inhibition of the cationic current (Zholos and Bolton, 1997). Thus, atropine inhibits the parasympathetic …show more content…
The results obtained in the experiment determined that the peristalsis responses, which are elicited by the stretch stimulation of the walls of the intestine, are mediated by the depolarization of the intrinsic primary neurons within the myenteric plexus that contains nerves that are essential for the peristalsis reflex, thus instigating the release of excitatory neurotransmitter (Furness, 2000). The release of the excitatory neurons then results in the stimulation of excitatory or inhibitory motor neurons, which prompts the contraction or relaxation of the smooth muscle respectively (Furness, 2000). Hence, as the inhibiting blockage activity of the drugs used in the experiment seem to reduce the neuronal conduction, and thus result in the inhibition of the amplitude of the peristalsis reflex. The neurons are part of the enteric system, and are involved in the muscarinic reflex activities (Furness, 2000). Hence, by using effective receptor antagonists, it was possible to illustrate that excitatory neurons have an essential role in the muscarinic component for smooth muscle contraction (Furness, 2000). Therefore, as the stretch or mucosal stimulation occurs in the ileum of the guinea pig, it is vital to examine the response of the intestine to the stimulation. The activation of the stretch receptors, which are present in the myenteric plexus, result in
Hence, due to the blocking properties of lignocaine, it prevents the depolarization of the postsynaptic neuron, and averts the initiation of an action potential (Sheu and Lederer, 1985). The effects of lignocaine on the intestinal smooth muscle are described to be concentration-dependent contractures (F A., 1986). Thus, in the experiment, as the amplitude of contraction was diminished, it demonstrated an anesthetic function of lignocaine on nociceptors (van den Broek et al., 2011). Another drug that was applied to the ileum tissue in the organ bath of Tyrode’s solution (37°C) was atropine, which exhibits a competitive antagonistic property, and has an antagonizing effect on the muscarinic acetylcholine receptors (Araki et al., 1976). Atropine is a non-specific anti-cholinergic antagonist drug that functions as a blockage of neuronal nicotinic acetylcholine receptors (nAChRs), and furthermore blocks the nicotine-induced responses (Cuthbert, 1963). Functioning as an antagonist, atropine binds to the M2 and M3 with high affinity and causes the inhibition of the cationic current (Zholos and Bolton, 1997). Thus, atropine inhibits the parasympathetic …show more content…
The results obtained in the experiment determined that the peristalsis responses, which are elicited by the stretch stimulation of the walls of the intestine, are mediated by the depolarization of the intrinsic primary neurons within the myenteric plexus that contains nerves that are essential for the peristalsis reflex, thus instigating the release of excitatory neurotransmitter (Furness, 2000). The release of the excitatory neurons then results in the stimulation of excitatory or inhibitory motor neurons, which prompts the contraction or relaxation of the smooth muscle respectively (Furness, 2000). Hence, as the inhibiting blockage activity of the drugs used in the experiment seem to reduce the neuronal conduction, and thus result in the inhibition of the amplitude of the peristalsis reflex. The neurons are part of the enteric system, and are involved in the muscarinic reflex activities (Furness, 2000). Hence, by using effective receptor antagonists, it was possible to illustrate that excitatory neurons have an essential role in the muscarinic component for smooth muscle contraction (Furness, 2000). Therefore, as the stretch or mucosal stimulation occurs in the ileum of the guinea pig, it is vital to examine the response of the intestine to the stimulation. The activation of the stretch receptors, which are present in the myenteric plexus, result in