Human digestive system, Ispiti' predlog Engleski jezik
andela-jocic
andela-jocic

Human digestive system, Ispiti' predlog Engleski jezik

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Human digestive system in english
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-Univerzitet: Medicinski fakultet Univerziteta u Nisu

-Odsek: Stomatologija

-Stident: Andjela Jocic

-Broj indeksa, 4623

Human digestive system

The human digestive system consists of a set of organs that are responsible for digestion, digestive tract plus the accessory organs of digestion like tongue, salivary glands, pancreas, liver and gallbladder. Digestion includes breakdown of food that human had ingested into a smaller and smaller components, until they can be absorbed and assimilate into the body . The whole process of digestion has many stages. The first stage of digestion is the cephalic phase which begins with gastric secretions that occurs even before the food enters the stomach, especially while it’s being eatten. It results from the sight, thought, smell or taste of food. The stimulation depends on appetite, the greater the appetite the more intense is simulation, that is caused by neurogenic signals originated from the cerebral cortex. The next stage of digestion starts in the mouth with chewing in which eatten food is being mixed with the saliva and with that begins the mechanical process of digestion. Out of that chewing process we get bolus which is a ball-like mixture formed out of food and saliva. That way eatten food can be swallowed down the esophaqus or commonly known as food pipe, which is an organ through which food passes. It is twenty five centimeters long in adults, positioned behind the trachea or commonly called as windpipe, and behind heart passes through the diaphragm and empties into the uppermost region of the stomach. The stomach is a major organ of digestive system, it is a J-shaped organ joined to the esophaqus with its upper end and to the duodenum with its lower end.​ ​The stomach is a expansible organ and can normally expand to hold about one litre of food. This expansion is enabled by a series of gastric folds in the inner walls of the stomach. The stomach of a newborn baby will only be able to expand to retain about thirty ml. At the stomach chewed food is being mixed with gastric acid(gastric juice) which is a digestive fluid produced in the stomach that plays a key role in digestion of proteins, by activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes break down the long chains of amino acids. As some chemicals can damage the stomach wall, as pepsin for example, phlegm is secreted by innumerable gastric glands in the stomach, to provide a slimy protective layer against the damaging effects of the chemicals on the inner layers of the stomach. The pylorus, the lowest section of the stomach

which attaches to the duodenum(first and the longest part of small intestine​ ​jointed C-shaped tube connecting the stomach to the jejunum, long betwen five to seven meters) via the pyloric canal, contains countless glands which secrete digestive enzymes including gastrin. After an hour or two, a thick semi-liquid called chyme is produced. When the pyloric sphincter, or valve opens, chyme enters the duodenum where it is mixed further with digestive enzymes from the pancreas, and then passed through the small intestine, where digestion continues into jejunum and ileum. When the chyme is fully digested, it is absorbed into the blood. Ninety five percent of absorption of nutrients occurs in the small intestine. Water and minerals are reabsorbed back into the blood in the colon of the large intestine, where the environment is slightly acidic. Most food digestion takes place in the small intestine. Then we have the large intestine which is consisted of three parts, the intestinum caecum, the intestinal colon, and the straight intestinal rectum. It is located around the small intestine and about 1,6m long. It contains a lot of bacteria that have the ability to synthesize vitamins that the body absorbs. In the colon, reabsorption of water and salt is performed and the collection of unwashed remains before their discharge is performed. Since the colon does not have its own enzymes, the remaining digestion is done with the aid of small intestine enzymes. The content in the colon lasts for eight to twelve hours, after which it comes to its ejection, that is defecation, through rectum.

DIGESTIVNI SISTEM

Digestivmi sistem se sastoji od skupa organa koji su odgovorni za varenje, cine ga probavni trakt i pomocni organi, poput jezika, pljuvacnih zlezdi, pankreasa, jetre i zucne kese. digestija obuhvata razlaganje hrane koje je covek uneo, na sitnije i sitnije delove, sve dok se mogu apsorbovati i uneti u telo. Ceo proces varenja ima puno faza. Prva faza digestije je cefalicna faza, koja pocinje sa zeludacnim sekrecijama, koje se javljaju cak i pre nego sto je hrana dospela u zeludac, narocito dok se ona zvace. To je rezultat opazanja , razmisljanja, mirisa i ukusa hrane. Stimulacija zavisi od apetita, sve veci apetit, veca je stimulacija, koja je uzrokovana, nurogenskim signalima nastalim u cerebralnoj kori. Sledeca faza digestije pocinje u ustima, zvakanjem, u kojoj se unesena hrana mesa sa pljuvackom, time pocinje mehanicki proces varenja, iz tog procesa zvakanja dobijamo bolus koji je oblika lopte, formirana iz hrane i pljuvacke. Na taj nacin, unesena hrana ce se progutati i dospeva zatim do jednjaka koji transportuje hranu, on je dug je 25 cm , smesten iza dusnika, a iza srca prolazi kroz dijafragmu i prazni se u gornjem delu zeludca. Zeludac je glavni organ odgovoran za varenje oblika je slova J povezanog gornjim krajem sa jednjakom, a sa tankim crevom svojim donjim krajem,. Zeludac je ekspazivni organ i fiziolloski se moze prosiriti, da primi oko 1 litar hrane, ovo sirenje omogucavaju resice sa unutrasnje strane zivodva zeludca. Zeludac novorodjencadi ce moci da se prosiri do 30 ml. U zeludcu hrana se mesa za zeludcanim sokovima, koja je digestivna tecnost

koja se proizvodi u zeludcu i koja igra kljucnu ulogu u varenju belancevina aktiviranjem digestivnih enzima, i nastaju proteini dejstvom ovih enzima sve dok ne nastanu amino kiseline. . Kako neke supstance mogu osetiti zeludcani zid , kao sto su pepsin, gastricne zlezde u zeludcu sekrecijom se formira zastitni sloj protiv stetnih efekata na unutrasnjim slojevima zeludca. pilorus, najnizi deo zeludca koji se vezuje za duodenum, prvi i najduzi deo tankog creva, u obliku slova C, koja peovezuju zeludac sa jejunumom, dugim od 5 do 7 metara, u piloricnom kanalu ima mnogoborjnih zlezda koje luce digestivne enzime ukljucujuci gastrin. Posle sat ili dva proizvedena je gusta polutecna masa. Kada se piloricni sfinkter otvori masa ulazi u duodenum, gde se dalje mesa sa pankreasnim enzimima, a zatim prolazi kroz tanko crevo, gde se nastavlja varenje, u jejunumu i ileumu. Kada se crevni sok razlozi apsorbuje se u krv. 25% materija iz crevnog soka se proizvodi u tankom crevu. Voda i minerali se ponovo apsorbuju u krv u koloonu gde je sredina blago kisela, mada se vecina varenja se odvija u tankom crevu, zatim imamo debelo crevo koje se sastoji od tri dela, slepog creva cekuma i rektuma. pozicioniranog oko taankog creva i duzina je 1,6 metasra sadrzi puno bakterija koje imaju sposobnost sintetisanja vitamina koje telo apsorbuje, u debelom crevu se vrsi apsorpcija vode i soli i formira nepreradjene ostatke pre nego sto se izvrsi praznjenje. Posto debelo crevo nema svoje enzime preostalo varenje se vrsi pomocu enzima dospelih iz tankog creva i tu ostaju 8 do 12 sati zatim dolazi do preznjenja preko analnog otvora.

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