Peristaltic Movement

The median lethal dose of lunacrine hydrochloride is 78-7 3-8 mgm. per kilo given intravenously in mice. Oral doses of 1 gramme of lunamarine are not fatal. The m.l.d. of lunacridine by mouth is 1,097 167 mgra. per kilo. Limamarine stimulates isolated rabbit intestine and uterus, but lunacrine and lunacridine inhibit peristaltic movement of the isolated intestine. All three alkaloids reduce arterial blood pressure in cats. ... 

Elderberry is not only nourishing, it also promotes a healthy metabolism. It helps break up mucus congestion, helps prevent free radicals from damaging healthy cells, treats constipation by loosening old fecal matter lodged in the colon and helps to stimulate natural peristaltic movement. Elder also helps eliminate water and fat that is unnecessarily stored in the body. 

An effective antidiarrheal agent that inhibits peristaltic movement is... 

Digestive system g agonists decrease secretion of stomach acid, reduce gastric motility, and prolong gastric emptying. Pancreatic, biliary, and intestinal secretions are reduced. Intestinal transit is also slowed. Peristaltic movements are reduced, but tone is increased, sometimes causing spasm. As a result, constipation is a frequent problem with opioid use. Bile duct pressure is also increased by opioids. 

NO is also a likely candidate for the NANC messenger of the myenteric plexus of neurons in the gastrointestinal tract, which mediate peristaltic movements. These neurons are rich in NO synthase and inhibitors of this enzyme prevent the nerve-evoked relaxation of the gut [12]. Nitric oxide released from nitroprusside also stimulates ADP ribosylation of glyceradehyde 3-phosphate dehydrogenase [56]. Consequently, there may be a number of enzymes, which are probably Fe-centered, that may be activated by NO. 

Adrenaline and noradrenaline reduce the peristaltic movements and the frequency of the intestinal smooth muscle both by a- and /3-adrenoceptor stimulation. The stimulation of 2-adrenoceptors at presynaptic neurons in the intestinal plexus reduces the release of activating transmitters, such as acetylcholine. 

Cestodes live in what might be termed a hazardous environment, in which the peristaltic movement of the gut and the passage of partly digested food make the possession of an efficient form of attachment an essential prerequisite for survival. 

Some species, e.g. E. granulosus, will evaginate their scolex in saline alone, but this process may be slow or only temporary, and such a response would be inadequate to bring about the rapid evagination and subsequent attachment to the mucosa which is required if the larva is to avoid being swept away by the continuous peristaltic movements of the gut. The addition of bile, however, produces almost instant evagination in most... 

Q3 The muscular wall of the colon is quiescent for much of the time. The major type of motility is segmentation but this is less frequent than in the small intestine. It mixes and moves colonic contents around to promote reabsorption of water and electrolytes. Peristaltic movements also occur and promote colon emptying. The myenteric plexus in the wall of the colon coordinates both motor and secretory activity and affects activity of the internal sphincter at the junction of the colon and rectum. This sphincter is usually contracted and is maintained closed by sympathetic stimulation. Stimulation of parasympathetic nerves increases motor activity throughout the colon and relaxes the internal sphincter, allowing material to enter the rectum. 

Normal peristaltic movements mix the contents of the duodenum, bringing the drug particles into intimate contact with the intestinal mucosal cells. The drug must have a sufficient time (residence time) at the absorption site for optimum absorption. In the case of high motility in the intestinal tract, as in diarrhea, the drug has a very brief residence time and less opportunity for adequate absorption. 

Relief of postoperative atony of the gut and the urinary bladder. In such conditions, cholinergicstimulation may relieve the stasis by stimulating peristaltic movements of the intestine and ureters and by constriction of the bladder. 

The dissolution of a drug in the gut lumen will depend on luminal conditions, e.g., pH of the luminal fluid, volume available, lipids and bile acids and the hydrodynamic conditions produced from the GI peristaltic movements of the luminal content toward the lower bowel. Such physiological factors influence drug dissolution by controlling the different variables in equation 1 that describe the dissolution rate. This is summarised in Table 4.4 adapted from Dress-man et al. (1998). 

The nerve cell, or neuron, is an unusual looking cell (Fig. 8-1). A neuron may be only 0.1 mm in diameter but, may reach lengths of a meter or more. The threadlike extension from the cell body is the nerve fiber. These fibers interconnect in various special areas of the body, including the brain, the spinal cord, and the peripheral nerves. The function of the neuron is to transmit signals, or impulses. The dendrites specialize in receiving excitations, which may be from environmental stimuli (i.e., from peripheral parts of the body, or from another cell). The axon conducts the excitation away from the dendrite area (e.g., to the brain).1 This excitation, or impulse transmission, may be on a subconscious level. Transmissions of which the subject is not consciously aware are the type that control various body functions such as temperature, respiration, blood pressure, and peristaltic movements of the gastrointestinal tract. In addition to the traditional functions of a cell membrane, the membrane of the nerve fiber (the axon) has the role of transmitting the electrochemical impulses that are received from the dendrites. The additional protective device called the myelin sheath basically serves as an electrical insulator. 

The roots of this plant contain about 3 % of an alkaloid, C21H38O6N (m.p. 120-121°, [a] - -42.5° chloroaurate, m.p. 142°). It induces a fall in blood pressure and stimulates peristaltic movements when given intravenously to urethanized cats. It is not bactericidal nor is it appreciably toxic to paramecia (105). 

The basic propulsive movement of the GIT is peristalsis in which a contractile ring appears around the gut and then moves forward. The usual stimulus for peristalsis is distension of the gut wall, which stimulates the ENS to initiate peristaltic movement thus allowing the food to be propelled analward. 

Sonography may show dilated fluid-filled bowel loops. The obstructing cause can occasionally be visualized if it is a tumor or hernia. Absence of peristaltic movements, bowel wall thickening without perfusion on color Doppler imaging and dilated small bowel containing fluid can all indicate infarction in the appropriate clinical setting. 

US is able to show thickened bowel walls, separation of bowel loops because of thickened and edematous, hyperechogenic mesentery and absence of peristaltic movements. Color Doppler is useful to detect a higher flow velocity in the superior mesenteric artery and to identify areas of active inflam-... 

Fig. 4.10. Paralytic ileus. Sonogram of the lower abdomen shows dilated jejunum filled with fluid and debris. The dilated loops are essentially static and the bowel contents do not move. Note debris in the dependent part of the dilated loop (arrows), indicating no peristaltic movement...

Fig. 5.3. a Scan of the anterior abdominal wall with Valsalva manoeuvre shows the ventral hernia containing the bowel loops (BO) and the defect in the fascia (arrows), b Fatty epigastric hernia with herniation of the properitoneal fat (arrows), c Spigelian hernia shows the defect marked by calipers lateral to the rectus muscle (R) and the contents (BO) limited anteriorly by the Spigelian fascia (arrow), d Richter s type umbilical hernia shows fluid-filled hernial sac (arrowheads) and irreducible herniation of only a part of the circumference of the bowel (arrow), which showed wriggling peristaltic movement in real time... 

With a recorded waveform, we generally must assume that it represents the sum of nonsynchronized aperiodic signals, for example, from exogenic sources and endogenic activities such as respiration, peristaltic movements, heart beats, and nerve activities. In addition, there may be wideband noise and noise at discrete frequencies, for example, from the power line 50- or 60-Hz fundamentals. 

Peristaltic pumps are the ones most commonly used in FI. They consist of a motor-driven wheel with peripheral placed rollers and an adjustable compression cam (or band) that is squeezed against the rollers (Figure 2). The successive peristaltic movements of the tubes force various fluids through the tubes. The number of channels depends on the roller length and usually ranges from 1 to 16. Pump tubes are made of poly(vinil chloride) (PVC), silicone, or any other similar plastic material. Two collars are usually glued near the end of each pump tube with a dual purpose first, to serve as a point of attachment between the... 

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