Smooth Muscle Contraction (Rabbit Small Intestine) PDF
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Uploaded by AgileConsciousness9041
University of Basra
Abrar S. Abdulrazzaq
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Summary
This document details research on smooth muscle contraction in the small intestine of a rabbit. The introduction gives background information, the aim describes the experiment's objective, and the methodology outlines preparation and procedures, including solutions composition. Further sections cover different effects on the muscle.
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SMOOTH MUSCLE CONTRACTION (RABBIT SMALL INTESTINE) Lec. :Abrar S. Abdulrazzaq INTRODUCTION ◄ visceral smooth muscle contraction occurs spontaneously, meaning that it’s action potential generated without input from either motor or autonomic nervous system. ◄ smooth mu...
SMOOTH MUSCLE CONTRACTION (RABBIT SMALL INTESTINE) Lec. :Abrar S. Abdulrazzaq INTRODUCTION ◄ visceral smooth muscle contraction occurs spontaneously, meaning that it’s action potential generated without input from either motor or autonomic nervous system. ◄ smooth muscles controlled involuntary by endocrine and autonomic nervous systems. Visceral smooth muscle is characterized by the instability of its membrane potential(rhythmic oscillations) until reach threshold leading to continuous, irregular contractions independent of nerve supply this state called tonus or tone. the action potential spreads via gap junctions from muscle cell to another initiating a wave of muscle contraction in its way. SMOOTH MUSCLE CONTRACTION Kymograph:Kymograph is a device to record the magnitude of physiological variables. It basically consists of a revolving drum wrapped with a sheet of paper on which a stylus moves back and forth recording perceived changes of phenomena such as motion. AIM OF EXP To study some of autonomic properties of smooth muscle that occurs in the rabbit’s small intestine in response to different agents SACRIFICING THE RABBIT & REMOVING THE INTESTINAL SEGMENTS: 1-the animal should be sacrificed by head trauma(cervical dislocation),without use of anesthetic 2-cut the abdomen then locate the jujenum cut into pieces of 1inch length. 3-keep the pieces in a Petri plate containing Tyrode's solution. 4-Attach one hook to the anchor pin in the muscle chamber. 5-Fill the chamber with 100 ml warm Tyrode's solution and air bubble into the chamber (95% oxygen + 5 % carbon dioxide) ? COMPOSITION OF TYRODE’S SOLUTION Nacl 8.0 gm Kcl 0.2 gm NaHCO3 1.0 gm MgC.6H2o 0.1 gm CaCl22H2o 0.1 gm NaH2PO4.2H2o 0.05 gm Dextrose 1.0 gm RESEARCH TISSUE BATH 1-the jujenum segments will shorten when placed into the cold solution and motility will cease ,but when put into warm (37°c)solution inside the muscle bath motility will return within 5-10 min. 2- one of the advantages in adding drug directly to bath that rapid changes in muscle tonus can be clearly record. we recommend that solution be replaced between drug additions, it may take 1-2 min of the rhythm to stabilize after replacing the solution in the muscle bath. EFFECT OF PARASYMPATHETIC NEUROTRANSMITTER Acetylcholine, causes reduction in membrane potential and the spikes become more frequent and increase number of rhythmic contractions(increase tone) because it increase intracellular calcium ion concentration. EFFECT OF SYMPATHETIC NEUROTRANSMITTER Norepinephrine, its effect opposite to acetylcholine in which membrane potential becomes larger, the spikes decrease in frequency and muscle relax(decrease tone) H.W: if we add atropine to Tyrode’s solution what happen?
