Module 10 Flashcards
(81 cards)
Two Groups of the Digestive System
- Digestive Tract and 2. The Accessory Digestive Organs
The Digestive Tract (Alimentary Canal)
Mouth, oral cavity, pharynx, esophagus, stomach, small intestine, large intestine and anus
The Accessory Digestive Organs
Tongue, teeth, salivary glands, liver, biliary ducts and gallbladder and pancreas
Functions of the Digestive Tract
Continuous tube that starts in the oral cavity and ends inferiorly with the anal canal
Digestion
Masticiation crushes food into smaller pieces to facilitate chemical processing by enzymes into smaller molecules
Absorption
Digestion is completed in the small intestine where most nutrients are absorbed. In the large intestine, water, vitamines, etc are absorbed
Secretion
Cells of the stomach’s mucosal wall releases gastric acid to perform chemical digestion
Motility
When food is swallowed, muscles in the esophageal wall contract and relax to push food through the esophagus down to the stomach
Elimination of Waste
Leftover materials, which are not absorbed or utilized by the body are eliminated by the defecation
Mucosa - Digestive Tract
The innermost layer of the digestive tract wall and is composed of 3 main elements 1. surface epithelium 2. lamina propria 3. muscaris mucosa
What Does Surface Epithelium do
Reflects the expected function of the organ
Lamina Propria
Layer of loose connective tissue under the surface epithelium
Muscaris Mucosa
Smooth muscle fibres under the lamina propria
Submucosa
Layer below the mucosa, composed of dense irregular connective tissue and contains blood vessels, lymphatics, glands and nerve plexuses
Muscularis Externa
Composed of circular and longitudinal layers of smooth muscle with nerve plexuses in between layers. Responsible for muscle contraction to propel food through the digestive tract
Serosa/Adventitia
Outermost layer of the digestive tract
Serosa
When the outer layer is a serous membrane (a single layer of thin, flat cells that form a secrete lubricating fluid)
Adventitia
When the outer membrane is composed of loose connective tissue
Oral Cavity
The first part of the digestive tract. Composed of two parts 1. The vestibule and 2. Oral cavity proper
The vestibule
Space between the cheeks and lips and gums and teeth
Oral Cavity Proper
Other areas of the mouth
Palate
Makes up the superior border. It is divided into the hard palate (bone) and soft palate (muscle)
Uvula
The posterior extension of the soft palate
Deciduous Teeth
Two incisors, one canine (cuspid), two molars in each quadrant - 20 teeth in whole mouth