Systema Digestoria PDF | Universitas Gadjah Mada

SYSTEMA DIGESTORIA Laboratory of Animal Structure and Development Facultay of Biology, UGM Campbell Biology, 2021 Digestive organs: Digestive tract digestive glands FUNCTION: - Entering food (eating/feeding) - Save food temporarily - Digest physically chemically -...

SYSTEMA DIGESTORIA Laboratory of Animal Structure and Development Facultay of Biology, UGM Campbell Biology, 2021 Digestive organs: Digestive tract digestive glands FUNCTION: - Entering food (eating/feeding) - Save food temporarily - Digest physically chemically - Absorb digestive products - Temporarily save & eliminate leftovers (mengeluarkan sisa) ❖TEMPORARY STORAGE ORGANS ❖DIGEST THE FOOD PHYSICALLY VENTRICULUS 1. Chew INGLUVIES (crop) CHEEK POUCH Grate using: Oral teeth Grind Pharynx teeth Ventriculus 2. Mixing food with - peristaltic movement - antiperistaltic movement - segmentation movements (dividing motion of the stomach and intestines) In ventriculus & intestinum 5  ❖DIGEST THE FOOD PHYSICALLY (Cont …) 3. Moisturizing Soften with gastric juice Dissolving food intestinum 4. Fat emulsification by hepatic secretion  ❖DIGEST THE FOOD CHEMICALLY ▪ In ventriculus ▪ By enzymes produced in these ▪ Intestinum organs & pancreas Animals (ungulates, some marsupials) → use bacterial fermentation as a digestive tool → provide long storage in the stomach, caecum, or colon ❖FINAL RESULT OF ABSORBTION Need a large contact surface → between food juice and intestinal epithelium →in: - long intestinum - folds of intestinum wall - villi intestinalis - mikrovili Blind pouches known as pyloric caeca are found near the junction of the stomach and intestine in ray-finned fishes, especially teleosts. Their primary function appears to involve fat absorption, although they secrete a variety of digestive enzymes. No other vertebrate group possesses pyloric caeca. ❖DIGESTIVE SYSTEM 1. Digestive tract (tractus digestivus/ tractus gastrointestinalis/canalis alimentarius) 2. Digestive gland (glandula digestoria) ❖INCREASING OF DIGESTIVE SURFACE Increase the diameter of the digestive tract Increase the length of the digestive tract Internal folds & various protrusions Additional diverticula  MAIN PARTS OF THE DIGESTIVE TRACT A. INGRESIVE ZONE: take/put in food. Consists of lips, mouth, teeth, tongue B. PROGRESIVE ZONE: push food forward & start digest it. Consist of pharynx, esophagus, ventriculus C. DEGRESIVE ZONE: intestinum tenue, the longest & most important D. EGRESIVE ZONE: eliminate the residue. consists of the intestine crassum (Walter & Sayles, 1970)  ❖INGRESIVE ZONE Lips → 2 folds, can move, limit the mouth cleft Shape & area of mouth opening → depend on the types of food Mouth cavity consist of cavitas buccalis and cavitas oris Cavitas buccalis → between the cheeks and lips on the outside with the outer surface of the row of teeth & gums Where it ends up: Gld labialis → mucus Gld molaris Gld parotis → saliva In birds, turtles & monotremes absent, cavitas buccalis → cornificatio  ❖CAVITAS ORIS The cavity behind the row of teeth In higher vertebrates there is a palate: palatum durum in front area consist of bone Palatum mole in back area consist of connective tissues In Cyclostomata the surface of the tongue → horn teeth Fish doesn’t has mucus gland & saliva In Tetrapoda Tongue is generally fleshy & easy to move except in certain birds & reptiles Fog & toad tongue → originates at the front of the floor of the mouth → free end extended to catch prey Mammal’s tongue: The front → rough with a number of papillae (4 types) The back → = lymphoid tissue (tonsila lingualis) Oral glands: gladula lingualis, palatina, nasalis, maxillaris, sublingualis, submaxillaris Human tongue Papila filiform Papila fungiform Papila sirkumvalata Taste buds  SALIVA Consists of: water, organic ions, mucus proteins, salivary amylase enzymes and salivary maltase Functions: Keeps the mouth moist Lubricates food more easily through the pharynx Start → Carbohydrate digestion Poly saccharide +H2O amylase maltose, glucose Maltose +H2O maltase glucose  ❖ TEETH To grate, chop, grind, defend, attack, hold prey, assist locomotion In lower vertebrates → an indefinite number In high vertebrates → certain & limited number Location: premaxillare, maxillare, mandible, vomer, palate, pterygoidal The structure of tooth surface ▪ Selenodonts: crescent-shaped enamel projections: Ruminantian molars ▪ Bunodont: projection of the tubercle (spherical) enamel of human molars ▪ Lophodont: transverse strips → elephant Types of the tooth attachment 1. Acrodont: no root Attaches to the edge of the jaw, by means of a fibrous membrane  Types of the tooth attachment 2. Pleurodont: The base/one side of the tooth is attached to the inner edge of the jaw Lizard Types of tooth attachment 3. Thecodont: Have tooth roots, embedded in the jawbone pocket On mamal's teeth  Types of the tooth changes 1. Polyphyodont: the teeth change throughout life → shark 2. Diphyodont: replacement of deciduous teeth (milk teeth) by dentes permanentes → mammals in general 3. Monophyodont: dentes decidui remain as long as life as permanent teeth → Marsupialia (kangaroo)  Ratio of corona and radix 1. Brachydont: short corona, long radix → human 2. Hypsodont: long corona, short radix → horse, elephant ❖PROGRESIF ZONE Pharynx: Fish: no nares internus → food & respiration air enters together and parallel Amphibi: there is nares internus → food way & air way crossed Mammal: food crossing in the airways in the pharynx In the pharynx there are : glottis hole to the eustachian tube hole to the esophagus Esophagus (ES) and ventriculus: Fish: short ES, sometimes larger → ventriculus → various shapes Amphibia: short - ciliated ES, full of mucus glands, straight ventriculus, digestive Reptilia: longer ES, cilliated; in turtle →cornification, straight/curved ventriculus (Crocodilia round, muscular) The microanatomical structure of the gastrointestinal tract is basically similar TUNICA MUCOSA Consists of a single layer of cells, except for the esophagus Lamina propria: loose connective tissues Lamina muscularis mucosae TUNICA SUBMUCOSA: loose connective tissues TUNICA MUSCULARIS Stratum circulare & stratum longitudinale TUNICA SEROSA Outer sheath → mesenterium & peritoneum  ESOPHAGUS VENTRICULUS T mucosa Simple and cornified Simple columnar epithelium squamous epithelium Lamina propria: Loose Lamina propria thin, loose connective tissue & glands connective tissue Lamina muscularis mucosa: Lamina muscularis circular & longitudinal smooth mucosa: longitudinal muscle smooth muscle T submucosa Loose connective tissue Loose connective tissue, blood vessels, nerves, smooth muscle cells T muscularis Stratum circulare: smooth Stratum circulare & stratum muscle longitudinale: smooth muscle Stratum longitudinal: smooth & transverse striated muscles T serosa Loose connective tissue Loose connective tissue  DEGRESIVE ZONE ❖ = Intestinum Tenue ❖ Food mixed with  Bolus  Pancreatic juice  Gandular secretions on the wall of the intestine ❖ Break down into dissolved forms → absorbed in the intestinal wall ❖ In Cyclostomata there are longitudinal folds → typhlosol ❖ In Elasmobranchii → Typhlosol → Valvula spiralis ❖ In Reptilia → ceca coli ❖ In mammal  Herbivor: long Intestinum tenue, ceca coli is big  Intestinum → consist of duodenum, Jejunum, Illeum EGRESIVE ZONE ☺ = Intestinum crassum ☺ The part that comes out of the coelom → = rectum ☺ Posterior end = cloaca/anus ☺In this zone, the water is absorbed, feces are formed ☺ In Elasmobranchii on the dorsal rectum there are rectal glands → excrete salt ☺ In Aves → protrusion of the dorsal cloaca = bursa cloacalis/bursa Fabricii → formation of antibodies / maturation of B-lymphocytes  DIGESTIVE GLANDS (Hepar & pancreas) HEPAR  Largest digestive gland  Develops from the median intestine → 1 or 2 diverticula hepatica :  diverticula posterior, form vesica fellea  diverticula anterior expanding and branching → hepar  Produce bilus → poured into the duodenum when food enters the duodenum  Excess of bile production is temporarily stored in the vesica felea  Biliary tract from hepar → ductus hepaticus  Biliary tract from vesica fellea → ductus cysticus  Ductus hepaticus and ductus cysticus united → ductus choledocus  Pancreas Derived from diverticula intestinum  Diverticulum of the dorsal wall of the duodenum → pancreas dorsal Diverticulum hepaticum (in the ventral duodenum) → pancreas ventral  The growth of the duodenal wall is not the same → united → the ventral duct contains the dorsal duct → ductus pancreaticus is formed (d. Wirsungianus)  Proximal part d. dorsalis forms the accessory ducts (d. Santorini)  Pancreas has a dual role : Exocrine gland Endocrine gland Exocrine part ❖Cell type similar with the cell on glandula salivarius ❖ secretion of pancreatic juice Endocrine part:  consists of a group of cells → Insula Langerhans → scattered throughout the pancreas  hormone produced : Insulin, Glukagon