Strukturne prilagodbe probavnog sustava s obzirom na ishranu životinja

undergraduate thesis

• Title (english): Structural adaptations in animal digestive system considering diet
• Author: Ana Rukavina
• Mentor: Romana Gračan (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2020-10-02, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Način hranjena i vrsta hrane u velikoj su mjeri uvjetovali razvitak probavila i probavnih struktura. Beskralježnjaci imaju jednostavnije probavne strukture, koju najčešće čine usta i gastrovaskularna šupljina ili pak primitivni oblici crijeva i želuca. Viši kralježnjaci su posebno u središtu promatranja probavnih prilagodbi koje su nastale kao rezultat različitih tipova prehrane. Prema tipu prehrane uobičajena je podjela na biljojede, mesojede i svejede. Biljojedi imaju najsloženije probave strukture pošto je biljna hrana vrlo teška za probaviti. S druge strane, mesojedi imaju najjednostavnije probavilo. Probavne strukture koje su najvećim djelom modificirane zbog načina prehrane jesu želudac, crijeva i zubi. Smatra se da je kljun kod ptica rezultat načina prehrane, ali i djelovanja nekih drugih ekoloških čimbenika. Kod velikog broja vrsta je prisutna volja koja im pomaže u mehaničkoj obradi cjelovitih zalogaja. Uočeno je da neke karnivorne vrste mogu jesti i učinkovito razgraditi biljnu hranu bez posebnih struktura u prisutstvu bakterija koje fermentiraju biljke. Biljojedne vrste ne mogu razgraditi meso jer nemaju enzime koji bi im to omogućili. Osim na anatomskoj, životinje se prehrani prilagođavaju i na histološkoj razini. Tkiva sadrže brojne stanice koje luče probavne enzime i ostale pomoćne tvari poput primjerice sluzi, koje su bitne za noramalno odvijanje probave. Također tu su i slinske žljezde u ustima od kojih ustvari započinje probava te vrčaste žlijezde koje pomažu formiranju i lakšem formiranju fecesa kojeg organizam eliminira iz tijela van.

Abstract (english)

The way of eating and the type of food consumed by animals largely conditioned the development of the digestive system and digestive structures. Invertebrates have simpler digestive structures, most often made up of the mouth and gastrovascular cavity or primitive forms of the intestines and stomach. Higher vertebrates are especially at the center of the observation of digestive adjustments that have arisen as a result of different types of diet. According to the type of diet, the division into herbivores, carnivores and omnivores is common. Herbivores have the most complex digestive structures as plant foods are very difficult to digest. Carnivores, on the other hand, have simpler digestive system. Digestive structures that are mostly modified due to diet are stomach, intestines and teeth. It is believed that the beak shape in birds is the result of diet, but also the action of some other environmental factors. In large number of species, structure named crop helps them to mechanically process whole bites of food. It has been observed that some carnivorous species can eat and effectively digest plant foods without special structures – with help of fermenting bacteria. Herbivorous species cannot break down meat because they do not have the enzymes that would allow them to do so. In addition to anatomical, animals also adapt to various food on histological level. Tissues contain numerous cells that secrete digestive enzymes and other excipients such as mucus, which are essential for the normal digestion. There are also salivary glands in the mouth from which digestion actually begins, and goblet cells that help form and facilitate the formation of feces that the body eliminates from the body.

• Keywords: Probavni sustav
• Language: croatian
• URN:NBN: urn:nbn:hr:217:098708
• Study programme: Title: Environmental Sciences; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) struke znanosti o okolišu (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-10-07 11:18:46