Chapter 17 Flashcards
Define digestion?
Digestion refers to the mechanical and chemical breakdown of foods.
Define Ingestion?
Taking food into the mouth.
What are the 3 phases of eating?
- Cephalic
- Gastric
- Intestinal
Define absorption?
The passage of digested food from the GI tract into the bloodstream for distribution to cells.
What are the organs of alimentary canal?
Mouth
Pharynx
Esophagus
Stomach
Small and Large Intestines
What is meant by the “Movement of Food”?
the passage of food along the Gastrointestinal (GI) tract.
What is defaction?
the elimination of undigested material from the GI tract
What is rugae?
Mucosal folds in the stomach
What are the regoins of the stomach?
- Cardiac region – around esophagus
- Fundic region – upper area.
- Body region – main, central region
- Pyloric region – near duodenum
What are the acessory organs of alimentary canal?
Salivary Glands
Liver
Gall Bladder
Pancreas
How does food move through the esophagus?
Food moves through by:
- Gravity
- Peristaltic waves down the esophagus to the gastro-esophageal sphincter.
- Sphincter muscle relaxes
- Food moves into stomach.
What is emulsification?
- The process of breaking apart fat lobules into small droplets.
- This increases surface area and increases the effectiveness of lipases.
What is bile composed of?
- Bile salts
- Bile pigments
- Cholesterol
- Electrolytes
What is the uvula?
Extension of the soft palate
What are the four layers of alimentary canal starting with innermost.
- Mucosa
- Submucosa
- Muscularis
- Serosa
Describe the Mucosa layer of the alimentary canal.
innermost layer.
Composed of epithelium and areolar.
Epithelium extends into lumen = microvilli.
Contains glands that secrete mucous.
Functions: protection, secretion, and absorption.
Describe the submucosa layer of the alimentary canal.
beneath the mucosa.
Composed of areolar, blood and lymph vessels, and nerves.
Functions: nourishment of the mucosa and transportation of nutrients.
Describe the muscularis layer of the alimentary canal
2 layers of smooth muscle.
Circular muscle layer around the submucosa.
Longitudinal layer around the circular layer.
Function: movement of food through canal.
Describe the serosa layer of the alimentary canal.
Serosa – outermost layer.
Visceral peritoneum
Functions: lubrication and movement of canal in abdominal cavity.
Mesentery – intestinal peritoneal extensions that extend the length of the intestine.
Describe segmentation (mixing)
Food and digestive juices and mucous
Circular muscle layer.
Mixing movements due to occasional, random contractions in small “segments” of the canal.
Describe Peristalsis
Longitudinal muscle layer
Propelling action
As food passes, one section of the tube relaxes, opening next section and food moves on.
What is the gastroesophageal sphincter located?
Located between the esophagus and stomach
Where is the pyloric sphincter located?
Located between the stomach and small intestine
Where is the lleocecal valve (sphincter) located?
Located between the small and large intestine
Where are the internal/external anal sphincter located?
Located between the large intestine and
the exterior
What are deciduosus teeth? How many are there and when do they form and/or fall out?
baby teeth.
Approximately 20
Form between 6-32 months
Lost between ages 6-12.
What are Permanent (secondary) teeth? How many are there and when do they form and/or fall out?
Approximately 32
Form from age 6-adulthood
Permanent
What are the function of the teeth?
Functions: break food into smaller pieces.
Increases surface area of food.
Increase effectiveness of digestive enzymes
What are the four kinds of teeth and their function?
Incisors – front teeth; break food into bite-size pieces.
Cuspids = canine teeth; grasp and tear food.
Bicuspids and Molars = grinding of food particles.
What are the four componements of teeth?
Crown – exposed area of the tooth.
Root – area below the gum.
Enamel – covering on crown; calcium salts.
Dentin – bulk of the tooth.