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Gastroileal Reflex
The gastroileal reflex is one of the three extrinsic reflexes of the gastrointestinal tract, the other two being the gastrocolic reflex and the enterogastric reflex The enterogastric reflex is one of the three extrinsic reflexes of the gastrointestinal tract, the other two being the gastroileal reflex and the gastrocolic reflex. The enterogastric reflex is stimulated by duodenal distension. It can also be s .... The gastroileal reflex is stimulated by the presence of food in the stomach and gastric peristalsis. Initiation of the reflex causes peristalsis in the ileum and the opening of the ileocecal valve (which allows the emptying of the ileal contents into the large intestine, or colon). This in turn stimulates colonic peristalsis and an urge to defecate. References {{DEFAULTSORT:Gastroileal Reflex Reflexes Physiology Stomach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrointestinal Tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines. Food taken in through the mouth is digested to extract nutrients and absorb energy, and the waste expelled at the anus as feces. ''Gastrointestinal'' is an adjective meaning of or pertaining to the stomach and intestines. Most animals have a "through-gut" or complete digestive tract. Exceptions are more primitive ones: sponges have small pores (ostia) throughout their body for digestion and a larger dorsal pore ( osculum) for excretion, comb jellies have both a ventral mouth and dorsal anal pores, while cnidarians and acoels have a single pore for both digestion and excretion. The human gastrointestinal tract consists of the esophagus, stomach, and intestines, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrocolic Reflex
The gastrocolic reflex or gastrocolic response is a physiological reflex that controls the motility, or peristalsis, of the gastrointestinal tract following a meal. It involves an increase in motility of the colon consisting primarily of giant migrating contractions, or migrating motor complexes, in response to stretch in the stomach following ingestion and byproducts of digestion entering the small intestine. Thus, this reflex is responsible for the urge to defecate following a meal. The small intestine also shows a similar motility response. The gastrocolic reflex's function in driving existing intestinal contents through the digestive system helps make way for ingested food. The reflex was demonstrated by myoelectric recordings in the colons of animals and humans, which showed an increase in electrical activity within as little as 15 minutes after eating. The recordings also demonstrated that the gastrocolic reflex is uneven in its distribution throughout the colon. The sigm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterogastric Reflex
The enterogastric reflex is one of the three extrinsic reflexes of the gastrointestinal tract, the other two being the gastroileal reflex and the gastrocolic reflex. The enterogastric reflex is stimulated by duodenal distension. It can also be stimulated by a pH of 3-4 in the duodenum and by a pH of 1.5 in the stomach. Upon initiation of the reflex, the release of gastrin by G-cells in the antrum of the stomach is shut off. This in turn inhibits gastric motility and the secretion of gastric acid (HCl). __TOC__ Emptying inhibitory factors The stomach's contents are inhibited from emptying into the small intestine by: * duodenadistensionref name=encycom> * duodenal acidic pH * duodenal hypertonicity * increased osmolarity of gastric chyme * sympathetic stimulation * intense pain Emptying stimulatory factors The stomach's contents empty through the pylorus, allowing digestion to proceed, when there is: * parasympathetic The parasympathetic nervous system (PSNS) is one of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflexes
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus. Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs via neural pathways in the nervous system called reflex arcs. A stimulus initiates a neural signal, which is carried to a synapse. The signal is then transferred across the synapse to a motor neuron which evokes a target response. These neural signals do not always travel to the brain, so many reflexes are an automatic response to a stimulus that does not receive or need conscious thought. Many reflexes are fine-tuned to increase organism survival and self-defense. This is observed in reflexes such as the startle reflex, which provides an automatic response to an unexpected stimuli, and the feline righting reflex, which reorients a cat's body when falling to ensure safe landing. The simplest type of reflex, a short-latency reflex, has a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. ''Physiological state'' is the condition of normal function. In contrast, '' pathological state'' refers to abnormal conditions, including human diseases. The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Cells Although there are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
