Chapter 11 The digestive system Flashcards
The digestive system consists of …?
- a tube that runs from the mouth to the anus
- accessory digestive organs that aid the process of digestion and absorption of nutrients
The digestive tube is known as the …?
digestive tract, gastrointestinal tract (GI), the alimentary canal, or gut
Herbivores are …?
plant-eating animals
What animals are examples of herbivores?
cattle, sheep, goats
Carnivores are…?
meat-eating animals (cats)
Omnivores are…?
animals that eat plant material and meat
Monogastric animals are…?
simple, single stomachs
Ruminants have what kind of digestion process?
multiple mixing and fermentation compartments in addition to the stomach
What are the 4 digestive tract functions?
prehension mastication chemical digestion absorption of nutrients and water elimination of wastes
What is prehension?
grasping of food with the lips or teeth
What is mastication?
mechanical grinding and breaking down of food - chewing
What two animals do not have a gall bladder?
horses and rabbits
The walls of the GI tract is made up of multiple layers what are they?
mucosa, submucosa, muscle layer, and serosa
What is the mucosa layer in wall of the GI tract?
lining of GI tract; epithelium and loose connective tissue
What is the submucosa layer in wall of the GI tract?
is beneath the mucosa and contains dense connective tissue; may contain glands
What is the muscle layer in wall of the GI tract?
located outside the submucosa
What is the serosa layer in wall of the GI tract?
it is the outermost layer that consists of a thin, tough layer of connective tissue
The digestive tube in the abdomen is suspended from the dorsal body wall by sheets of connective tissue called?
mesentery
The mesentery contains…?
blood and lymph vessels and nerves that supply the GI tract
What two types of epithelium line the digestive tube?
stratified squamous epithelium
simple columnar epithelium
What is thick and tough and lines the mouth, pharynx, and esophagus at one end of the tube and the anus at the other end?
stratified squamous epithelium
What runs from junction of esophagus and stomach through the intestines to junction of rectum and anus and the nutrients are absorbed through this thin epithelium
simple columnar epithelium
What are the two kinds of muscles that make up the wall of the digestive tube?
skeletal muscles and smooth muscles
Skeletal muscle is under _____ control and is present in what four areas?
voluntary
mouth, pharynx, the cranial part of the esophagus, and the external anal sphincter
Smooth muscle is present in the _____ of the rest of the digestive tube such as… (6 areas)
wall
the majority of the esophagus, the stomach, the small intestine, the large intestine, and the internal anal sphincter
The contents of the digestive tract are moved and mixed by two main types of smooth muscle contractions, what are they?
peristalsis (peristaltic contractions) and segmental contractions
What does a peristalsis contraction do?
have circular muscle contractions, wavelike moves contents along the tract, propel digestive tract contents along the tube ahead of them
What do segmental contractions do?
have periodic circular muscle contractions, occur in different adjacent sites, and mixes digestive tract contents and slows their movement through the tract
In most of the GI tract, the muscle is arranged how?
in circular and longitudinal layers
