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There are three main divisions — the left gastric artery , the common hepatic artery and the splenic artery. The abnormality may sometimes be localized to the large or small intestine by history, physical examination, and fecal characteristics see Table: Distention activates long and myenteric reflexes. What makes a carb good and what makes it bad? They are made of a bone-like material called dentin , which is covered by the hardest tissue in the body— enamel.
DIGESTIVE SYSTEM Defined for Kids
The stomach has three main roles. It stores swallowed food. It mixes the food with stomach acids. Then it sends the mixture to the small intestine. Most people have a problem with their stomach at any time. Indigestion and inflammation are common problems. You can relieve some stomach problems with over-the-counter medicines and lifestyle changes, such as avoiding fatty foods or eating more slowly. Other problems like peptic ulcers or GERD require medical attention. The most common symptom of a stomach ulcer is a burning or gnawing pain that develops in your abdomen.
The pain can also travel up to your neck, down to your navel belly-button or through to your back. The pain associated with a stomach ulcer is caused by the ulcer itself and stomach acid that comes into contact with the ulcer and irritates it. The pain can last from a few minutes to a few hours. Abdominal bloating is a condition in which the abdomen feels uncomfortably full and tight and may be visibly swollen distended.
Bloating is a common complaint, affecting between 10 and 30 percent of adults. Severe abdominal pain and bloating that occur suddenly, especially if you also have nausea and vomiting, may be a sign of a bowel obstruction from scar tissue or a tumor pressing on the bowel. The glands located in your mouth and throat. The most important secretion glands are the salivary gland, submandibular, and articulator glands.
They all secrete saliva into your mouth, the salivary gland through tubes that drain saliva referred to as salivary glands, close to your higher teeth, submandibular beneath your tongue, and therefore the articulator through several ducts within the floor of your mouth.
Besides these glands, there are small glands referred to as minor salivary glands placed in your lips, inner cheek space buccal mucosa , and extensively in alternative linings of your mouth and throat. Home Publications Conferences Register Contact. Guidelines Upcoming Special Issues. Publication Policies and Ethics. Submit Manuscript Journal Impact Factor 0. About the Journal Index Copernicus Value Gastric Cancer Gastric cancer is that the third commonest reason for cancer-related death within the world, and it remains troublesome to cure in Western countries, primarily as a result of most patients gift with advanced sickness.
Gastrointestinal Inflammation The term inflammatory bowel disease IBD describes a group of disorders in which the intestines become inflamed. Digestive Enzymes Digestive enzymes area unit found within the organic process tracts of animals and humans and within the traps of carnivorous plants, wherever they aid within the digestion of food, similarly as within cells, particularly in their lysosomes, wherever they perform to keep up cellular survival.
Gastrointestinal Hormones GI hormones are chemical messengers that are involved in several aspects of physiological functions of the canal, as well as the regulation of secretion, absorption and digestion, and gut motility. Intestinal Blockage An obstruction can occur when there is no passageway for food or digested food to move through the bowel, or intestine.
Epigastric Pain Epigastric pain is pain that's localized to the region of the higher abdomen just below the ribs. Gall Bladder The bladder is largely a pear-shaped pouch for storing bile a liquid created by the liver to assist digest fatty foods. Gastrointestinal Radiology Radiologists within the channel Radiology Section perform and interpret picture taking studies of the tract, as well as the throat, esophagus, stomach, duodenum, bowel, colon, and biliary system.
Pancreas The Pancreatic gland is regarding 6 inches long and sits across the rear of the abdomen, behind the abdomen. Gastrointestinal Infections Diarrhea , that is characterised by frequent and watery intestine movements, is usually caused by canal infections, though it may return from different sicknesses or changes in diet.
Gastrointestinal Surgery The digestive system is an intricate system that can be disrupted by disease, diet and emotional stress.
Related Journals of Gastrointestinal Surgery Gastroenterology Journals , World J Gastroenterology , Advances in Surgery, American Journal of Surgery, Arab Journal of Gastroenterology, Best Practice and Research in Clinical Gastroenterology Gastrointestinal Pharmacology Diseases of the digestive tract that need medicine management, sometimes together with different treatments, square measure peptic ulcers omeprazole and others , hurting laxatives, analgesics , looseness of the bowels antibiotics, protectants and absorbents, glucocorticoids , motility inhibitors , reperfusion injury, operative enteropathy prokinetic drugs , and adhesions.
Endoscopy Endoscopy is a procedure that looks inside your stomach. Ti and Ri transfer between bacteria uses an independent system the tra , or transfer, operon from that for inter-kingdom transfer the vir , or virulence , operon. Such transfer creates virulent strains from previously avirulent Agrobacteria. In addition to the use of the multiprotein complexes listed above, Gram-negative bacteria possess another method for release of material: Vesicles from a number of bacterial species have been found to contain virulence factors, some have immunomodulatory effects, and some can directly adhere to and intoxicate host cells.
While release of vesicles has been demonstrated as a general response to stress conditions, the process of loading cargo proteins seems to be selective. The gastrovascular cavity functions as a stomach in both digestion and the distribution of nutrients to all parts of the body.
Extracellular digestion takes place within this central cavity, which is lined with the gastrodermis, the internal layer of epithelium. This cavity has only one opening to the outside that functions as both a mouth and an anus: In a plant such as the Venus Flytrap that can make its own food through photosynthesis, it does not eat and digest its prey for the traditional objectives of harvesting energy and carbon, but mines prey primarily for essential nutrients nitrogen and phosphorus in particular that are in short supply in its boggy, acidic habitat.
A phagosome is a vacuole formed around a particle absorbed by phagocytosis. The vacuole is formed by the fusion of the cell membrane around the particle. A phagosome is a cellular compartment in which pathogenic microorganisms can be killed and digested. Phagosomes fuse with lysosomes in their maturation process, forming phagolysosomes.
In humans, Entamoeba histolytica can phagocytose red blood cells. To aid in the digestion of their food animals evolved organs such as beaks, tongues , teeth, a crop, gizzard, and others. Birds have bony beaks that are specialised according to the bird's ecological niche. For example, macaws primarily eat seeds, nuts, and fruit, using their impressive beaks to open even the toughest seed. First they scratch a thin line with the sharp point of the beak, then they shear the seed open with the sides of the beak.
The mouth of the squid is equipped with a sharp horny beak mainly made of cross-linked proteins. It is used to kill and tear prey into manageable pieces. The beak is very robust, but does not contain any minerals, unlike the teeth and jaws of many other organisms, including marine species.
The tongue is skeletal muscle on the floor of the mouth that manipulates food for chewing mastication and swallowing deglutition. It is sensitive and kept moist by saliva. The underside of the tongue is covered with a smooth mucous membrane.
The tongue also has a touch sense for locating and positioning food particles that require further chewing. The tongue is utilized to roll food particles into a bolus before being transported down the esophagus through peristalsis. The sublingual region underneath the front of the tongue is a location where the oral mucosa is very thin, and underlain by a plexus of veins.
This is an ideal location for introducing certain medications to the body. The sublingual route takes advantage of the highly vascular quality of the oral cavity, and allows for the speedy application of medication into the cardiovascular system, bypassing the gastrointestinal tract. Teeth singular tooth are small whitish structures found in the jaws or mouths of many vertebrates that are used to tear, scrape, milk and chew food.
Teeth are not made of bone, but rather of tissues of varying density and hardness, such as enamel, dentine and cementum. Human teeth have a blood and nerve supply which enables proprioception. This is the ability of sensation when chewing, for example if we were to bite into something too hard for our teeth, such as a chipped plate mixed in food, our teeth send a message to our brain and we realise that it cannot be chewed, so we stop trying.
The shapes, sizes and numbers of types of animals' teeth are related to their diets. For example, herbivores have a number of molars which are used to grind plant matter, which is difficult to digest. Carnivores have canine teeth which are used to kill and tear meat. A crop , or croup, is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion.
In some birds it is an expanded, muscular pouch near the gullet or throat. In adult doves and pigeons, the crop can produce crop milk to feed newly hatched birds. Certain insects may have a crop or enlarged esophagus. Herbivores have evolved cecums or an abomasum in the case of ruminants. Ruminants have a fore-stomach with four chambers.
These are the rumen , reticulum , omasum , and abomasum. In the first two chambers, the rumen and the reticulum, the food is mixed with saliva and separates into layers of solid and liquid material.
Solids clump together to form the cud or bolus. The cud is then regurgitated, chewed slowly to completely mix it with saliva and to break down the particle size. Fibre, especially cellulose and hemi-cellulose , is primarily broken down into the volatile fatty acids , acetic acid , propionic acid and butyric acid in these chambers the reticulo-rumen by microbes: In the omasum, water and many of the inorganic mineral elements are absorbed into the blood stream.
The abomasum is the fourth and final stomach compartment in ruminants. It is a close equivalent of a monogastric stomach e. It serves primarily as a site for acid hydrolysis of microbial and dietary protein, preparing these protein sources for further digestion and absorption in the small intestine. Digesta is finally moved into the small intestine, where the digestion and absorption of nutrients occurs.
Microbes produced in the reticulo-rumen are also digested in the small intestine. Regurgitation has been mentioned above under abomasum and crop, referring to crop milk, a secretion from the lining of the crop of pigeons and doves with which the parents feed their young by regurgitation. Many sharks have the ability to turn their stomachs inside out and evert it out of their mouths in order to get rid of unwanted contents perhaps developed as a way to reduce exposure to toxins.
Other animals, such as rabbits and rodents , practise coprophagia behaviours — eating specialised faeces in order to re-digest food, especially in the case of roughage. Capybara, rabbits, hamsters and other related species do not have a complex digestive system as do, for example, ruminants.
Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft faecal pellets of partially digested food are excreted and generally consumed immediately.
They also produce normal droppings, which are not eaten. Young elephants, pandas, koalas, and hippos eat the faeces of their mother, probably to obtain the bacteria required to properly digest vegetation.
When they are born, their intestines do not contain these bacteria they are completely sterile. Without them, they would be unable to get any nutritional value from many plant components. An earthworm 's digestive system consists of a mouth , pharynx , esophagus , crop , gizzard , and intestine. The mouth is surrounded by strong lips, which act like a hand to grab pieces of dead grass, leaves, and weeds, with bits of soil to help chew.
The lips break the food down into smaller pieces. In the pharynx, the food is lubricated by mucus secretions for easier passage. The esophagus adds calcium carbonate to neutralize the acids formed by food matter decay.
Temporary storage occurs in the crop where food and calcium carbonate are mixed. The powerful muscles of the gizzard churn and mix the mass of food and dirt. When the churning is complete, the glands in the walls of the gizzard add enzymes to the thick paste, which helps chemically breakdown the organic matter.
By peristalsis , the mixture is sent to the intestine where friendly bacteria continue chemical breakdown. This releases carbohydrates, protein, fat, and various vitamins and minerals for absorption into the body. In most vertebrates , digestion is a multistage process in the digestive system, starting from ingestion of raw materials, most often other organisms. These bacteria perform several useful functions, such as synthesizing various vitamins , processing waste products and food particles, and protecting against harmful bacteria.
When the descending colon becomes full of stool, or feces, it empties its contents into the rectum to begin the process of elimination. The rectum Latin for "straight" is an 8-inch chamber that connects the colon to the anus. It is the rectum's job to receive stool from the colon, to let you know there is stool to be evacuated, and to hold the stool until evacuation happens.
When anything gas or stool comes into the rectum, sensors send a message to the brain. The brain then decides if the rectal contents can be released or not. If they can, the sphincters muscles relax and the rectum contracts, expelling its contents.
If the contents cannot be expelled, the sphincters contract and the rectum accommodates, so that the sensation temporarily goes away.
The anus is the last part of the digestive tract. It consists of the pelvic floor muscles and the two anal sphincters internal and external muscles. The lining of the upper anus is specialized to detect rectal contents. It lets us know whether the contents are liquid, gas, or solid.
The pelvic floor muscle creates an angle between the rectum and the anus that stops stool from coming out when it is not supposed to. The anal sphincters provide fine control of stool. The internal sphincter keeps us from going to the bathroom when we are asleep, or otherwise unaware of the presence of stool. When we get an urge to go to the bathroom, we rely on our external sphincter to keep the stool in until we can get to the toilet. Continued Three organs play a pivotal role in helping the stomach and small intestine digest food: Pancreas Among other functions, the oblong pancreas secretes enzymes into the small intestine.
Liver The liver has many functions, but two of its main functions within the digestive system are to make and secrete bile, and to cleanse and purify the blood coming from the small intestine containing the nutrients just absorbed.