Digestive Anatomy & Physiology (AnSci 101)

Flashcards covering key vocabulary related to avian, ruminant, and hindgut fermenter digestive anatomies and physiologies, as well as general nutrition concepts.

Crop (Avian)

A storage site in birds until the rest of the digestive tract is ready to receive more food.

Proventriculus (Avian)

The glandular stomach in birds.

Gizzard (Ventriculus) (Avian)

The mechanical stomach in birds, often containing pebbles or grit for grinding food.

Ceca (Avian)

Blind pouches at the junction of the small and large intestines in birds that re-absorb water, ferment coarse feed, and produce B vitamins.

Cloaca or Vent (Avian)

A common orifice in birds for waste elimination, breeding, and egg laying in females.

Ruminant

An animal with four connected stomach compartments (e.g., cattle, sheep, goats) that functions to use roughage (cellulose) as a source of energy.

Foregut Fermenter

An animal where microbial populations living in the first three compartments of the stomach ferment feed.

Fermentation

Enzymatic breakdown of energy-rich compounds in an anaerobic environment.

Dental pad (Ruminant)

A tough, fibrous pad in the upper jaw of ruminants, replacing upper incisor teeth.

Salivary Glands (Ruminant)

Produce large quantities of saliva to lubricate feed, provide liquid for bacteria & protozoa, buffer the rumen, and recirculate nitrogen and minerals.

Rumination / Ruminating (Chewing cud)

The regurgitation of food, followed by re-chewing, and then re-swallowing in ruminants.

Eructating (or Eructation)

The act of burping, expelling gases (CO2 and CH4) produced by fermentation in ruminants.

Reticulum

The smallest ruminant stomach chamber, lined by honeycomb ridges, involved in fermentation and susceptible to Hardware Disease.

Rumen

The largest ruminant stomach chamber, a fermentation vat with muscular sacs and folds, providing an ideal warm, anaerobic environment for microorganisms.

Reticuloruminal contractions

Rhythmic contractions in ruminants that expel gases, regurgitate partially digested plants, and move feed particles to the third stomach chamber.

Volatile Fatty Acids (VFAs)

Energy-rich compounds (Acetic Acid, Butyric Acid, Propionic acid) produced by microbial fermentation in the rumen, providing 50-80% of the ruminant's total energy needs.

Rumen Degradable Protein

Dietary protein utilized by microbes in the rumen to make their own protein.

Rumen Undegradable Protein

Dietary protein that escapes the rumen and is absorbed in the small intestines.

Omasum

The third ruminant stomach chamber, a globe with many internal parallel muscular folds, that absorbs water, bicarbonate ions, and remaining VFAs.

Abomasum

The fourth ruminant stomach chamber, also known as the 'true' stomach, which performs acidic and enzymatic digestion of feed.

Esophageal groove

A reflex contraction in nursing calves/lambs/kids that allows milk to bypass the reticulum and rumen, passing directly into the abomasum.

Monogastric

An animal with a stomach that has 1 compartment (e.g., horses, rabbits).

Hindgut Fermenter

Monogastric herbivores where microbial breakdown and fermentation of roughage occurs after the stomach, in the cecum and large intestines.

Nutrients

Feed substances necessary for life, for cells to live, grow, and function, composed of elements or compounds.

Water (Nutrient)

An essential nutrient that gives the body physical shape, participates in metabolic reactions, transports nutrients, eliminates waste and excess heat, and helps maintain fluid and ion balance.

Ration/Diet

The feed given to an animal.

Balanced Ration

A diet that contains all the nutrients an animal needs in the right proportions and amounts.

Moisture

The water content within a feed or ration.