Gastrointestinal Smooth Muscle Report

This activity is the critical driving force of muscle contraction. The stream of action potentials along the muscle fiber surface is terminated as Acetylcholine at the neuromuscular junction is broken down by acetyl cholinesterase. The release of Calcium ions is ceased. The action of the myosin molecule heads is obstructed because of the change in the configuration of troponin and tropomyosin due to the absence of calcium ions. This will eventually cause the contraction to be ceased. Together with these physical processes, an external stretching force such as gravity pulls the muscle back to its normal length.

If acetylcholine is not liberated than it would also not cause an action potential which would not cause a muscle contraction.

In this experiment, contractions of the earthworm gut are measured in an organ bath with a force transducer. The effect of neurotransmitters and ionic concentrations on contraction strength and rate will be investigated.

-Sarcoplasmic Reticulum (SR) then releases Calcium which binds to troponin in the thin filament, exposing myosin-binding sites;

The purpose of this study was to compare contractility of individual preparations glycerinated rabbit psoas muscle exposed to two different solutions known to cause muscle contraction. A standard contracting solution without 15 mM of creatine phosphate and a second contracting solution with 15 mM of creatine phosphate were compared to one another. Creatine phosphate has been found as

Smooth muscle contraction occurs when calcium is present in the smooth muscle cell and binds onto calmodulin to activate myosin light chain kinase (Wilson et al., 2002). Phosphorylation of myosin light chains result in myosin ATPase activity thus cross-bridge cycling occurs causing the muscle to contract (Horowitz et al., 1996). There are two known models of excitation and contraction in smooth muscle, electromechanical coupling (EMC) and pharmomechanical coupling

Table 5. The effects of Atropine measured by the ventricle of the frog’s heart by amplitude, period, and BPMs.

Martini, F. H., Nath, J. L., and Bartholomew, E. F. “Muscle Tissue.” Anatomy & Physiology. 9th

Once stimulated by the chemoreceptor trigger zone, the integrative vomiting centre coordinates the activation of all the nearby neural structures required to produce the multifaceted patterned response that will then lead to the processing and action of vomiting. The integrative vomiting centre coordinates the various inputs to the motor component of the emetic reflex, consisting of both somatic and autonomic systems, as the reflex involves both voluntary and involuntary processes. The abdominal and respiratory musculature, and visceral components involved in mediating changes in gastric motility and gastric tone are controlled by somatic pathways, while the autonomic pathways control sweating, salivation and pallidity of the skin. The activation of autonomic pathways plays a role in the intensity and duration of the nausea that accompanies emesis, as opposed to the actual action of vomiting (myVMC,

The heart serves an important purpose within the body, pumping blood throughout the circulatory system to supply all parts of the body with vital nutrients and molecules. It pumps oxygen and nutrient rich blood to be exchanged for carbon dioxide, which is then pumped to the lungs and eliminated from the body. The movement of blood throughout the body is due to the heart’s ability to push blood along the circulatory system at a steady, unfaltering rate. This rate, known as heart rate, is regulated and can be altered at a moment’s notice by signaling within the body and heart itself. In vertebrates, the autonomic nervous system controls and regulates heart rate. The autonomic nervous system is divided into two subunits, the sympathetic nervous system and parasympathetic nervous system. The parasympathetic nerve that innervates the heart is the vagus nerve. In this laboratory experiment, the regulation of heart rate was observed by studying a certain breed of turtle, the Red-eared Slider (Trachemys scripta elegans). Both chemical and electric signaling can influence the components of the nervous

As shown in the table 2 the EC50 values of acetylcholine, calculated from the dose-response curve, significantly differ from each other. In fact, in endothelium denuded rings acetylcholine caused no relaxation at all. Moreover, the prolonged exposure to increasing concentrations had given some constriction.

The LES is a 3-4 cm. long segment of contracted smooth muscle at the end of the esophagus consisting of two separate components. The first component is the sphincter comprised of a segment of smooth muscle in the lower esophagus and the second component is formed by the diaphragm crus which exerts pressure. The LES creates a high pressure region between the esophagus and the stomach that prevents acid reflux. A LES that is fully functioning must have an acceptable total and intra-abdominal length, and a normal resting pressure. The LES prevents gastroesophageal reflux but it can be made difficult by numerous factors. During inspiration, the gastro-esophageal pressure gradient can drive gastric contents into the esophagus. The LES also allows

The autonomic nervous system is composed of nerves leading from the central nervous system (CNS) that innervate and control smooth muscle cardiac muscle, and glands it controls many organs systems automatically its actions are not generally under voluntary control( Quizlet,2017). The autonomic nervous system is divided into two parts the sympathetic nervous system and the parasympathetic nervous system. Usually, if one system stimulates a function, the other inhibits it. The policies oppose one another in governing the functions of smooth muscle and glands in many parts of the body. Some of the significant effects of the two systems are compared.

Immunohistochemical analysis for smooth muscle actin (SMA) was done and the intensity of staining and staining location were considered.

A decrease in stimulus frequency results in a greater number of contractions within the ileum. An increase