Chapter 11 - Digestive System Flashcards
What is prehension
The grasping of food
What are the functions of the digestive system
Prehension, ingestion, mastication, digestive tract , Absorption of nutrients and water, elimination of waste
What is ingestion
The taking in of food
What is mastication
Chewing of food
What is the digestive tract
Also known as G.I. tract, alimentary canal
List the layers of tissue that compose the wall of the G.I. tract from superficial to deep
- Serosa.
- Muscularis composed of longitudinal muscle layer and circular muscle layer
- Submucosa
- Mucosa
What is the serosa.
Serosa is a serous membrane which is the outermost layer of the wall of the G.I. tract
What is the serosa composed of
Epithelium, basement membrane, lamina propria
What is the function of the serosa
Protection and secretion, serous fluid reduces friction between layers
What is the muscularis externa composed of
Mainly composed of involuntary smooth muscle. Longitudinal and circular
What is the longitudinal smooth muscle do in the muscularis externa
Shorten tube
What does the circular smooth muscle layer of the muscularis externa do
Constricts the tube
What do the longitudinal and circular smooth muscle in the muscularis externa aid in
The aid in the propulsion of food from the esophagus to the rectum. By means of peristalsis and segmentation
What are sphincters
Thickened rings of circular smooth muscle which act like valves throughout the tract
Where is skeletal muscle found
Mouth, pharynx, cranial portion of the esophagus, and external anal sphincter
What is the skeletal muscle used for
Aids in chewing and swallowing, and defecation
What is peristalsis
Progressive contractions of smooth muscle propelling food down the G.I. tract
What is segmentation
Alternating contractions move food back-and-forth to mix and slow progress down in G.I. tract
What is the submucosa and what does it contain
The submucosa is a layer of loose connective tissue containing blood vessels, lymphatic vessels, follicles, nerves. Elastic fibers allow stretching and restoration of shape
What is the mucosa and what does it contain
The mucosa is a mucous membrane which is the innermost layer. Contains epithelium, basement membrane, lamina propria, muscularis mucosae
What are the functions of the mucosa
Secretion: mucus, digestive enzymes and hormones. Absorption of nutrients and water. Protection against disease
What are the two anal sphincter’s
Internal: internal anal sphincter that’s involuntarily controlled
External: external anal sphincter voluntarily controlled
What are two serous membranes in the body
Parietal layer which lines the cavities. Visceral layer which covers organs
Where is plural membrane located
Thoracic cavity