Animal Digestive Systems: Ruminant, Monogastric, Avian, and Hind-gut Fermenters

A comprehensive set of vocabulary flashcards covering the terminology and anatomy of ruminant, monogastric, avian, and hind-gut fermenter digestive systems.

Digestion

The process of breaking feed down into simple substances that can be absorbed by the body.

Absorption

The process of simple molecules passing through cell membranes of the lining in the small intestine into the blood.

Amino acids

The building blocks of protein that contain carbon, hydrogen, oxygen, and nitrogen; they are essential for growth and maintenance of cells.

Bolus

A small mass of feed once swallowed by animals.

Chyme

Partially digested feed that is acidic, semifluid, gray, and pulpy that is produced in the stomach and sent to the small intestine.

Enzymes

Organic catalyst substances that speed up the digestive process.

Gastric Juice

A liquid containing water, mucus, hydrochloric acid, and digestive enzymes that are secreted by glands.

Microbes

Single-celled organisms found in the rumen and reticulum that aid in digestion.

Peristalsis

Involuntary muscular contractions that create wave-like movements to move canal contents.

Prehension

The process of grasping feed with lips, tongue, and/or teeth.

Rumination

The process of forcing feed back up the esophagus to be chewed further to increase digestibility of roughages; also known as "chewing the cud."

Villi

Small finger-like projections in the intestinal wall that increase the surface area and aid in digestive absorption.

Ruminants

Animals that have stomachs divided into multiple chambers and digest large amounts of roughages compared to non-ruminants.

Rumen

The largest section of the ruminant stomach, making up part of the $85\%$ stomach capacity, and is the primary site for microbial fermentation.

Reticulum

A compartment on the left side with an interior lining resembling a honeycomb that takes in liquids to soak food for microbial digestion.

Hardware disease

An illness caused by cattle swallowing foreign objects like nails or wire, which can be prevented by a small magnet in the reticulum.

Omasum

A round, muscular part of the stomach with many layers of tissue responsible for grinding and squeezing roughage to remove liquid.

Abomasum

The "true stomach" of the ruminant that secretes enzymes and gastric juices and contains hydrochloric acid to act on feed particles.

Small Intestine

A long coiled tube divided into the duodenum, jejunum, and ileum where chyme is mixed with bile and pancreatic juice; it is the primary site of nutrient absorption.

Cecum

A blind pouch located between the small and large intestines; it is much larger in hind-gut fermenters for digesting roughages.

Large Intestine

A tube divided into the colon and rectum that absorbs water and adds mucus to undigested feed to form feces.

Monogastric

Animals that possess a single-compartment stomach, chew their food, and typically cannot digest as much roughage as ruminants.

Avian Digestive System

A system specialized for birds that includes structures like the crop, proventriculus, and gizzard to soften and grind food.

Crop

An oval sac-like structure between the esophagus and proventriculus that stores and softens feed using saliva secretions.

Proventriculus

The true stomach in birds where gastric acids and enzymes aid in the digestive process.

Gizzard

An oval-shaped, muscular, purplish organ in birds that uses grit and gravel to crush feed particles.

Ceca

Two blind pouches in birds located between the small and large intestines that contain soft, undigested feed.

Cloaca

An enlarged part of the avian digestive tract where the digestive and reproductive tracts combine before waste or eggs are excreted.

Vent

The external opening at the end of the avian digestive, urinary, and reproductive systems.

Liver

The largest gland in the body which produces bile that acts on fats.

Pancreas

An organ that produces digestive enzymes including trypsin, pancreatic amylase, and lipase.

Trypsin

An enzyme produced by the pancreas that breaks down remaining proteins.

Pancreatic amylase

An enzyme that changes starch not processed by salivary amylase into maltose.

Lipase

An enzyme that acts on fats to convert them into fatty acids.

Gallbladder

A sac on the liver that stores bile; it is not present in horses.

Hind-gut Fermenters

Animals with a developed cecum containing microbes that ferment fiber (cellulose) after the small intestine, allowing them to get energy from plant material.