DIGESTIVE SYSTEM

Parts of the Digestive System

Parts of the Digestive system Mouth

Functions○ mechanical digestion

Teethbreak 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 cartilagecloses trachea (windpipe) when

swallowingfood travels down esophagusPeristalsis

involuntary muscle contractions to move food along

Parts of the Digestive System Stomach

Functions○ disinfect food

hydrochloric acid = pH 2kills bacteria

○ food storagecan stretch to fit food

○ digests proteinpepsin 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 intestineattached 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-absorbednot enough water re-absorbed

- diarrhea too much water re-absorbed

- ConstipationAdd mucus to undigested feed

Inside your large intestine are millions of helpful bacteria

Parts of the Digestive System Pancreas

Produces different enzymes for digestionNeutralizes stomach acid in small intestine

DIABETES!!

Parts of the Digestive System Liver

Production of Bile○ Dark green to yellow fluid that digests lipids

GallbladderStores 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

GizzardCrushes feed

○ Contains grit and gravelMixes feed with digestive juices

Liver Small and Large Intestine Vent

Removes solid and liquid waste

GIBLETS!!

NON-RUMINANTSMono-gastric Stomachs

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)BodyRoot (near the throat)

The muscles are oriented longitudinal, perpendicular, and transverse.

Stomach The simple stomach is made up of 4

parts:FundusCardia (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 nutrientselimination of solid wastes (defecation)

Ruminant Digestive Systems

The digestive system of ruminant animals includes the :Mouth - grasps the foodTeeth - 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