Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download Comparative Digestive Systems Topic 3024
Transcript
Comparative Digestive Systems Topic 3024 Amanda Moore Torey Birchmeier Modified by Ashlee Gibson Digestive Systems Overviews Digestion • Digestion: Breaking down large, nutrient macromolecules into simpler molecules for use by an organism. • Food enters the mouth and goes through mechanical and chemical changes as it passes through the alimentary canal. Types of Stomachs • Simple Stomach – Man, Pig • Complex Stomach – Cattle, Sheep, Goats • Simple Stomach with enlarged ceacum – Horses, Rabbits, Guinea Pigs Parts of Digestive Tract • Mouth: initial opening of alimentary canal – Salivary Glands • secrete juices that contain enzymes to help break up the food – Mastication • chewing, crushing, preparing food for swallowing Parts of Digestive Tract • Pharynx: funnel shaped muscle between mouth and esophagus – part of digestive and respiratory tracts • Esophagus: muscular tube connecting pharnyx to stomach – muscle contractions move food down to stomach Parts of Digestive Tract • Stomach: located between esophagus and small intestine – Two basics types • Simple • Ruminant Parts of Digestive Tract Simple Stomach • Humans, swine, rabbits and horses – Divided into three regions • cardiac • fundus • pylorus Simple Stomach • Digestion: – is mechanical, muscle contractions – is chemical, enzymes soften and break down macromolecules of food • enzymes are catalysts, they start the chemical reactions Simple Stomach • Enzymes that break down food – Gastric-break down proteins in stomach – Liver and pancreatic-break down fats in small intestine – Intestinal-break down carbohydrates and proteins in small intestine Parts of Digestion Tract Ruminant Stomach • Sheep, Cows and Goats • Occupies 3/4 of the abdominal cavity Four Components of Ruminant Stomach • Rumen – composes 80% of ruminant stomach in mature bovine animals and 30% in young animals • Reticulum – composes about 5% of bovine stomach – prevents indigestible objects from entering the stomach Four Components of Ruminant Stomach • Omasum – composes 7-8% of bovine stomach – absorbs mostly water • Abomasum – the “true” stomach – composes 7-8% of stomach in mature animals and 70% in young animals Digestion in the Ruminant Stomach • Rumination: The process of regurgitation, re-mastication, re-salivation and reswallowing of food. • Purpose: To smash and break up food which provides more surface area bacteria to break down Parts of Digestive Tract • Small Intestine: long, coiled tube connecting the stomach with the large intestine. – Is covered by villi which increases surface area to increase absorption – Food moves through by muscle contractions called peristaltic movement – Final breakdown and absorption of nutrients occurs here Parts of the Digestive Tract • Large Intestine – Includes cecum, colon and rectum – Absorbs water – Very little nutrient absorption takes place here Parts of the Digestive Tract Accessory Organs • Pancreas – produces and secretes digestive enzymes – produces insulin which regulates carbohydrate metabolism • Liver – produces bile-breaks down fatty acids – stores iron, handles fats and carbohydrates in the blood
