Animal Nutrition and Digestion

Bio 112

Herbivore

An organism that primarily eats plant material.

Carnivore

An organism that primarily eats other animals.

Omnivore

An organism that eats both plant and animal material.

Detritivores

Organisms that feed on dead organic matter.

Gastrovascular cavity

A digestive cavity found in diploblastic organisms such as flatworms, allowing for digestion and distribution of substances.

Alimentary canal

A digestive system with a hollow tube that extends from the mouth to the anus, present in triploblastic organisms.

Monogastric

A type of digestive system with one stomach cavity.

Coprophagy

The act of eating feces to aid in digestion.

Crop

The part of a bird's digestive system that stores food.

Proventriculus

The part of a bird's digestive system that produces gastric chemicals.

Gizzard

A muscular part of a bird's digestive system that grinds food using swallowed stones.

Ruminants

Herbivorous animals such as cows, sheep, and goats that digest cellulose-rich plant material.

Reticulum

The first chamber in the stomach of ruminants where food is mixed with bacteria for fermentation.

Rumen

The second chamber in the stomach of ruminants where most of the fermentation occurs.

Abomasum

The true stomach of ruminants where acid digestion occurs.

Ingestion

The process of taking in food.

Digestion

The process of breaking down food into smaller molecules.

Absorption

The process by which nutrients are taken up into the bloodstream from the digestive tract.

Elimination

The process of expelling indigestible waste from the body.

Oral cavity

The mouth area involved in ingestion and initial digestion of food.

Mastication

The mechanical breakdown of food by chewing.

Bolus

The ball of food formed in the mouth for swallowing.

Esophagus

The tube that connects the pharynx to the stomach.

Peristalsis

The wave-like muscle contractions that move food through the digestive tract.

Lower esophageal sphincter

The muscle that controls the passage of food from the esophagus into the stomach.

Pyloric sphincter

The muscle at the bottom of the stomach that controls the flow of chyme into the duodenum.

Hydrochloric acid (HCl)

A strong acid secreted in the stomach that helps digest food.

Pepsin

A protease that breaks down proteins into smaller peptides in the stomach.

Chyme

The thick, semi-liquid mixture of food, digestive juices, and acids in the stomach.

Small intestine

The part of the digestive system where most digestion and absorption occur.

Pancreas

An accessory gland that secretes digestive enzymes and bicarbonate into the small intestine.

Liver

An organ that produces bile to help digest fats.

Gallbladder

An organ that stores bile produced by the liver.

Duodenum

The first section of the small intestine where most chemical digestion occurs.

Salivary amylase

An enzyme in saliva that begins the digestion of carbohydrates.

Trypsin

A protease produced by the pancreas that further digests proteins in the small intestine.

Lipases

Enzymes that digest fats.

Jejunum

The middle section of the small intestine where absorption of nutrients occurs.

Ileum

The last section of the small intestine that absorbs nutrients and connects to the large intestine.

Cecum

The first part of the large intestine.

Appendix

A small, finger-like projection from the cecum that may have immune functions.

carbohydrate digestion

begins in oral cavity and continues in the small intestine.

protein digestion

begins in the stomach. HCl unfolds proteins, and pepsin breaks peptide bonds, making smaller polypeptides. In the small intestine, carboxypeptidase further break down polypeptides into amino acids.

nucleic acid digestion

occurs in small intestines. exposed to nucleaseand further broken down into nucleotides.

lipid digestion

Bile emulsifies fats with bile salts. digested by lipases.