Digestive System

Jr/Sr Veterinary Science

Mrs. Chotkowski #1

Functions

Intake & digestion of foodAbsorption of nutrientsElimination of solid waste

products

StructuresOral cavity & pharynxEsophagusStomachSmall IntestinesLarge Intestines, rectum,

anus

Oral Cavity (Mouth) Lips: responsible for ingestion Prehension: Grasping of food Tongue: organ which tastes food; contain

papillae (bumps & ‘taste buds’) Mastication: Breaks food into pieces with

saliva Teeth: grind food

– Deciduous dentition: temporary ‘baby’ teeth– Permanent dentition: adult teeth

Esophagus

Collapsible, muscular tube; brings food to the stomach

Peristalsis: waves of muscle contraction that move food through the digestive tract

The Stomach

Stores food, begins digestion Monogastric (Simple Stomach):

– Humans, pigs, dogs, cats Monogastric w/ a functional cecum:

– Horses, rabbits Ruminant (four compartments):

– Cattle, sheep, goats (chew cud)

Monogastric (Dog)

What are the parts A – G ?

Monogastric w/ Functional Cecum

Ruminant

Digestive Juices

Saliva (mouth); lubricates feed, contains amylase, which breaks down starch

Bile (liver); helps break down fat Intestinal juices: contain enzyme

peptidase, to break down proteins, & maltase, sucrase, & lactase to break down sugars

Gastric Juices

HCl: stops action of amylase Pepsin: enzyme, digests proteins Rennin: enzyme, digests milk protein Lipase: enzyme, digests fats Mucus: protects stomach lining Gastrin: stimulates stomach to produce

more juices

Pancreatic juices

Lipase: breaks down fats Trypsin: Breaks down proteins Chymotrypsin: acts on proteins Amylase: works on starch

Ruminant Digestion Rumen: largest compartment, serves as

a fermentation vat Reticulum: honeycomb, helps filter feed Omasum: contains papillae that help

grind food Abomasum: true stomach, secretes

gastric juices, starts protein digestion

Small Intestine

Duodenum: first portion, continues digestion

Jejunum & Ileum: rest, performs absorption of nutrients into the bloodstream

Large Intestine

Cecum: enlarged first portion, contains micro-organisms, fermentation vat

Colon: absorbs water and forms feces Rectum: carries feces to the anus Anus: passes solid wastes out of body

The End