AN4102 Companion Animal Anatomy and Physiology - Lecture 18

Vocabulary flashcards identifying structures and physiological functions of the digestive systems in companion animals, covering monogastric mammals, hindgut fermenters, avian species, and ruminants.

Dog Teeth

Dogs have $42$ teeth (compared to humans who have $32$) which are designed to tear and chew through tough surfaces.

Upper Oesophageal Sphincter

A muscular structure that relaxes to allow passage of food pushed by the tongue to the back of the mouth.

Epiglottis

A structure that closes over the opening to the trachea during swallowing to prevent food from entering the lungs.

Peristalsis

A wave of muscular activity that passes through tubular organs in a wormlike fashion, forcing substances to move steadily from the beginning of the tube to its terminus.

Pepsin

A protein-digesting enzyme found in gastric juices.

Gastrin

A hormone found in gastric juices that controls the digestive process via feedback mechanisms.

Chyme

A semi-liquid mixture of partially digested food and gastric fluids produced in the stomach.

Villi

Tiny finger-like projections lining the small intestine that increase the surface area available for nutrient absorption.

Bile (Gall)

A fluid supplied by the liver that alkalinises intestinal contents and plays a major role in fat absorption.

Pancreatic Exocrine Function

The secretion of acid-neutralising bicarbonate and several digestive enzymes.

Pancreatic Endocrine Function

The supply of hormones, such as insulin, that circulate throughout the body and help control metabolism.

Insulin

A pancreatic hormone that controls glucose metabolism; an inadequate usage or lack of it results in diabetes mellitus.

Duodenum

The first region of the small intestine, used for digestion and nutrient absorption.

Jejunum

The longest portion of the small intestine, used for digestion and nutrient absorption.

Ileum

The shortest portion of the small intestine, used for digestion and nutrient absorption.

Glycogen

The form in which the liver stores converted sugars for energy storage.

Caecum

A small, finger-like projection near the junction of the small and large intestine that aids fluid absorption and microbiological health.

Segments of the Large Intestine

The ascending colon, transverse colon, and descending colon.

Monogastric

A digestive system referring to an organism with a single-chambered stomach, found in humans, dogs, and rabbits.

Stomach pH (Monogastric)

The acidic environment provided by the stomach, typically having a pH between $1.5$ and $2.5$.

Caecotrophy's

Soft faeces produced by rabbits that are re-ingested to further digest plant material.

Crop

A pouch in the avian oesophagus that stores food.

Proventriculus

The first of two avian stomachs where gastric juices are produced to digest food.

Gizzard

The second avian stomach where food is stored, soaked, and mechanically ground, sometimes with the aid of stones or grit.

Cloaca

The terminal opening in birds where uric acid from the kidneys and waste from the digestive process are combined and excreted.

Ruminant Stomach Compartments

The four chambers used to digest cellulose: the rumen, reticulum, omasum, and abomasum.

Abomasum

The "true" stomach of a ruminant, equivalent to the monogastric stomach chamber where gastric juices are secreted.

Omasum

The third stomach of a ruminant that removes water from the cud.

Cud

Regurgitated food from the reticulum that ruminants chew again before swallowing into the omasum.