The human digestive system is constantly in motion. This is necessary to transport absorbed substances in the body to the organs. Peristalsis in this context refers to the muscular activity of the hollow organs in the body that serve this digestion. A distinction can be made between forward and backward peristalsis.
What is peristalsis?
Hollow organs are organs whose cavity is enclosed with a tissue. These include, for example, the esophagus, stomach, and intestines. The movement of these organs, called peristalsis, occurs in waves and thrusts.
Function and task
Peristalsis refers to the muscular activity of the hollow organs in the body that serve digestion. Peristalsis is controlled by nerve cell plexuses that are autonomously controlled in the intestinal wall. The neuronal regulation of peristalsis is the responsibility of the enteric nervous system. Four types of movement are distinguished in intestinal peristalsis. In propulsive peristalsis, the contraction of normally smooth muscle moves in a ring-like fashion. It transports the contents of the hollow organ in one direction. After ingestion, the food pulp passes through the stomach into the duodenum and then continues in small portions into the small intestine. Further transport into the small intestine also occurs only in batches. As the porridge is passed on, it is mixed with digestive fluid and enzymes. The transport can take different lengths of time and varies from person to person. However, the amount of dietary fiber and the liquid absorbed also play a role in transport. If there is little fluid in the organism, transport in the digestive system can be delayed. The process by which the intestinal wall moves forward and retracts is also known as intestinal motility. The autonomic nervous system is responsible for the functioning of peristalsis. Local reflexes are particularly influenced by the interaction of the sympathetic and parasympathetic nervous systems, which provide fine regulation of organ activity. The parasympathetic nervous system is part of the autonomic nervous system. It slows the heart rate and promotes digestion. The nerve plexus on the intestinal wall responds to these signals, causing the muscles to tense and relax rhythmically. The food pulp is thus transported further. Non-propulsive peristalsis involves the mixing of the intestinal contents. The contraction waves are annular and triggered by local reflexes. This step is also called rhythmic segmentation. If the transport proceeds in the normal rhythm and in the correct direction, it is called orthograde peristalsis. If the normal direction of transport is reversed, such as by a surgical procedure, or a slowdown in transit time, retrograde peristalsis is present. In retrograde peristalsis, the food pulp does not enter the intestine but is transported back through the esophagus. Vomiting is the side effect that results from this process. In ruminants this mechanism is also found – in their case deliberately. The process of retrograde peristalsis is also a significant process in the colon. The colon is driven by mass movements that occur at periodic intervals. These movements occur up to three times a day. The contents of the intestine are carried to the rectum and the gastrocolic reflex allows the stool to eventually be expelled. Increased peristalsis is seen when food has just been ingested. During periods of rest and slow walks, bowel movement is particularly stimulated. In many people, the intake of caffeine additionally causes an increase in peristalsis.
Diseases and ailments
If the body is highly concentrated and very concerned with performance, peristalsis reduces and shuts down most gastrointestinal activity. If inflammation in the abdominal cavity paralyzes the intestinal muscles, a reduction in peristalsis is also evident. During peristalsis, sounds are heard in the stomach and intestines. Due to the different intensity of the sounds, it is possible for a doctor to assess diseases. With the help of an examination, the possible diseases are clarified. If the peristalsis mixes too large food components or thin liquids, bubbling noises occur. Flatulence is also noticeable in the form of bowel sounds.The air bubbles move through the intestine and cause sounds in this way. The physician uses a stethoscope to better locate and interpret the bowel sounds. Normal bowel sounds are brisk and lively over all four quadrants of the abdominal corner. Ultrasound examination of the abdomen also provides information about movement in the gastrointestinal tract. Magnetic Marker Monitoring is a newly developed method that allows a capsule swallowed by the patient to track and analyze the digestive process. If the bubbling proves to be very violent, it may indicate diarrhea. If the patient suffers from the food intolerance lactose intolerance, bowel sounds can be heard as well. If no sound is heard during an examination of the intestines, this indicates in most cases an intestinal obstruction (ileus). In this case, paralysis of the intestinal wall occurs. If severe abdominal pain and blood in the stool are other symptoms, a doctor should be consulted to make a diagnosis and develop a treatment plan. Intestinal obstruction can also be mechanically caused them. The intestinal wall tries to break through the obstruction. This process makes the intestinal sounds more noticeable. A cause of mechanical ileus can be a foreign body in the intestine, or a cancerous tumor. Based on the bowel sounds, a definite diagnosis is not yet possible. Further diagnostic measures are taken to find out the exact cause. Depending on which disease in the intestine it is, medicinal or surgical procedures are used as therapy. If it is a tumor or a mechanical ileus, surgery is the only way out.
