Comparative Digestion Systems
& Processes
Modified by Ashlee Gibson

The Digestion Process
• Food is broken down
• Animals have digestive systems adapted to the foods that they consume
• Four types of digestive systems
– _____________________________________
– _____________________________________
– _____________________________________
– ______________________________________

Ruminant Digestive System
Modified to handle the breakdown of large amounts of
_________________

Ruminant Digestive System
• Mouth
– no upper ___________________, hard palate
– molars for grinding coarse vegetation
– saliva does not contain ___________________
• _______________________________
– muscular tube connecting the mouth to the stomach

Ruminant Digestive Systems
The Four Compartmented Stomach
• Rumen: storage area and
_______________________________
• Reticulum: nails and wire may be found here-_____________________ stomach
• Omasum: eliminates excess
___________from feed
• Abomasum: true stomach, _____________ and __________________ are secreted

Ruminant Digestive Systems
Stomach (cont.)
• _______________: first step in rumination
– large quantities of roughage are consumed and are chewed just enough to swallow
– after swallowing, regurgitation (“cud chewing”) takes place, food is re-chewed

Ruminant Digestive System
• Small Intestine
– connects stomach to large intestine
– ______________________________________
– contains bile and pancreatic juices
– pushes food through by muscle contractions

Ruminant Digestive System
• Large Intestine
– Contains Cecum, Colon and Rectum
• ____________________: sac at junction of small intestine and large intestine
• Colon and rectum: at end of system
– not as long as small intestine, but larger in diameter
– water and some nutrient absorption occurs here
– where residue solidifies before excretion

Monogastric Digestive System
Characterized by inability to digest roughage efficiently

Monogastric Digestive System
• Mouth
– has upper and lower incisors
– ________________________ secreted which breaks down nutrients
• Esophagus
– connects mouth to stomach

Monogastric Digestive System
• Stomach
– secretes _________________________ to break down nutrients
– enzymes such as ______________ also secreted here
– churning action mixes food
• Small and Large Intestine
• function just as in ruminant systems

Avian Digestive Systems
Characterized by several organs not found in other species that are adapted for grinding hard or encased food

Avian Digestive Systems
• Mouth
– ____________________________________
– Salivation excretion ____________________
• Esophagus
– has a modification called the _____________ which stores and moistens food
– connects mouth and stomach

Avian Digestive Systems
• Stomach
– Contains two parts
• _______________________________: same as monogastric stomach and provides digestive excretions
• _______________________________: located after proventriculus, very muscular, used to grind food

Avian Digestive Systems
• Small Intestine
– similar functions as in ruminants and monogastric systems
• Large Intestine
– similar functions as in ruminants and monogastric systems
– _____________________ chamber into which urinary and genital canals open
– ___________________ aids in fiber digestion and absorption

Equine Digestive Systems
Characterized by non-ruminant animals that consume and digest feeds high in fiber

Equine Digestive Systems
• Mouth
– intact top and bottom incisors
– molars adapted to chewing fibrous feeds
– no digestive enzymes in saliva
• Esophagus
– not well adapted for _____________________
– connects mouth and stomach

Equine Digestive System
• Stomach
– similar to monogastric system
• Small intestine
– similar to monogastric and ruminant systems
– ____________________ to store bile
– enlarged _______________ to aid in fiber breakdown

Equine Digestive System
• Large Intestine
– similar to monogastric systems
– _________________________ (at junction of small and large intestines) and colon take up most of the volume of the equine digestive system