DIGESTIVE SYSTEM

Parts of the Digestive System

Parts of the Digestive system Mouth Functions mechanical digestion Teeth break up food chemical digestion (saliva) amylase enzyme digests starch mucus protects soft lining of digestive system lubricates food for easier swallowing buffers neutralizes acid to prevent tooth decay anti-bacterial chemicals kill bacteria that enter mouth with food

Parts of the Digestive System Epiglottis flap of cartilage closes trachea (windpipe) when swallowing food travels down esophagus Peristalsis involuntary muscle contractions to move food along

Parts of the Digestive System Stomach Functions disinfect food hydrochloric acid = pH 2 kills bacteria food storage can stretch to fit food digests protein pepsin enzyme

Part of the Digestive System Small Intestine Functions digestion digest carbohydrates amylase from pancreas digest proteins trypsin & chymotrypsin from pancreas digest lipids (fats) bile from liver & lipase from pancreas absorption

Parts of the Digestive System Small Intestine Made up of three parts Duodenum Jejunum Ileum

Parts of the Digestive System Cecum first part of the large intestine attached to the appendix Its purpose is to absorb excess fluids and lubricate food with mucus to allow it to pass along the remainder of the digestive tract with ease. Also act as storage

Parts of the Digestive System Large Intestine functions: Water absorption > 90% of water re-absorbed not enough water re-absorbed diarrhea too much water re-absorbed Constipation Add mucus to undigested feed Inside your large intestine are millions of helpful bacteria

Parts of the Digestive System Pancreas Produces different enzymes for digestion Neutralizes stomach acid in small intestine DIABETES!!

Parts of the Digestive System Liver Production of Bile Dark green to yellow fluid that digests lipids Gallbladder Stores the bile

Taurine

POULTRY

Poultry                                    Chickens Turkeys Ducks Geese

Poultry Digestive Systems Mouth or beak Can not chew food Esophagus Connects mouth to crop Crop Stores feed

Poultry Digestive Systems Gizzard Crushes feed Contains grit and gravel Mixes feed with digestive juices Liver Small and Large Intestine Vent Removes solid and liquid waste

GIBLETS!!

Mono-gastric Stomachs Non-ruminants

Non-ruminants Animals that only have one stomach (mono-gastric). Dogs, cats, horses, bears, humans, etc. They can either be herbivores, omnivores, or carnivores.

Mouth Teeth All teeth are made up of incisors, canines, pre-molars, and molars.

Mouth Animals have three different types of salivary glands (parotid, mandibular, sublingual) They moisten the food They lubricate the mouth Add enzymes and bicarbonate salts

Tongue A mass of muscle covered by mucous membranes. Divided into three parts: Apex (rostral end) Body Root (near the throat) The muscles are oriented longitudinal, perpendicular, and transverse.

Stomach The simple stomach is made up of 4 parts: Fundus Cardia (near the esophagus) Body (largest) Pylorus

Carnivore Very Well developed stomach Uncomplicated intestine Limited fiber digestion

Omnivore More complicated GIT than carnivores Colonic digesters Pigs, humans Cecal digesters rat

Herbivore Cow- ruminant Horse- simple stomach, large cecum, large sacculated LI Rabbit- larger stomach, very large sacculated cecum, unsacculated LI

The Ruminant Digestive System

Ruminant Digestive Systems Functions of the digestive system of animals include: eating (ingestion) chewing (mastication) swallowing (deglutition) absorption of nutrients elimination of solid wastes (defecation)

Ruminant Digestive Systems The digestive system of ruminant animals includes the : Mouth - grasps the food Teeth - grind the food Ruminants have only one set of teeth in the front of the mouth (incisors), and two sets in the back (molars).

Reticulum - full

Reticulum - cleaned

Ruminant Digestive Systems While the animal is “chewing its cud” foreign particles that are heavy are allowed to “sink” in the reticulum, preventing many foreign particles from entering the rest of the digestive system. Once foreign material enters the reticulum, it stays there for the life of the animal.

Telephone Cord

Wire

Sponge taken from digestive system of an animal

Ruminant Digestive Systems Rumen - the organ that allows for bacterial and chemical breakdown of fiber. 25 to 50 billion bacteria The rumen has a very thick, muscular wall. It fills most of the left-side of the abdomen Largest compartment holding 50 gallons.

Ruminant Digestive Systems The walls of the rumen contain papillae (that can be up to 1 cm. in length), where the bacteria that are used to breakdown fiber live. In some ruminants (dairy cattle) the rumen can have a capacity of 55-65 gallons!

Papillae in Rumen

Papillae in Rumen

Ruminant Digestive Systems Omasum - section that is round and muscular. “Grinds” the food material and prepares the food material for chemical breakdown. Compartment known as the filter

Omasum - full

Ruminant Digestive Systems Abomasum - very similar to the stomach of non-ruminants. this is where the majority of chemical breakdown of food material occurs. mixes in digestive enzymes (pepsin, rennin, bile, etc.).

Abomasum – inside view