DIgestive Flashcards
Process by which food substances are changed into forms that can be absorbed through cell membranes.
Digestion
Nutrients within the GI tract are not inside the body until they are?
Absorbed from the intestines
To take food in
Ingestion
Chewing, Peristalsis, Churning
Mechanincal Digestion
Breaks down food particles through a series of metabolic reactions
Chemical Digestion
Movement-peristalsis
Propulsion
Passage of digested food from Gi tract into bloodstream
Absorption
Elimination of indigestible wastes
Defecation
Allimentary canal is also known as?
GI tract
What is the GI tract called? Where does it start and end?
Muscular tube, mouth and anus
What does the allimentary canal pass through?
Body’s ventral cavity
How long is the GI tract?
Around 28 ft
What does the Allimentary canal run through?
The entire tract
Name the four layers of the alimentary canal wall.
- Mucosa(inner)
- Submucosa
- Muscularis
- Sercsa(outer)
Innermost layer, surrounds lumen of tract
Mucosal
3 layers of the Mucosal
- Mucus epithelium
- Lamina Propria
- Muscualris Mucosae
Histology of Mucosal
Epithelium, Simple Columnar
What do glands of mucosal do?
Secrete mucus
Function of Mucosal layer
a. Protects again disease
b. Secretes mucus and enzymes
c. Absorption of end products of digestion(Mucus)
Beneath the mucosal layer
Submucosal layer
Histology of Submucosal?
Loose CT, glands, blood vessels, lymph vessels, nerves
Function of submucosal
Nourishes mucosa, carries absorbed nutrients away
This layer of smooth muscle between submucosal and serosa
Muscularis Layer
Two layers of Muscularis
A. Circular Layer- around submucosa, controls diameter of passage way
B. Longitudinal Layer- Around circular layer, allows length of passageway to change
Function of Muscularis layer
Movement of food along the tract
Outermost layer
Serosal Layer
Histology of Serosal
tough, fibrous connective tissue
Functions of serosal layer
Lubrication, and free movement of canal on abdominal cavity
What are the movements of the tube?
Mixing and propelling nutrients
Wave-like contractions
Peristalsis
Circular muscle which prevents backflow
Sphincter muscles
(cardiac) sphincter, betweeen esophagus and stomach
Gastroesophageal Sphincter
Between the stomach and the small intestine
Pyloric Sphincter
Small intestine and large intestine
Ileocecal valve
Large intestine-Smooth muscle
Internal anal sphincter
Large Intestine-Skeletal muscle
External anal sphincter
Small outer region bounded by the lips and cheeks on the outside and gums and teeth on the inside
Vestibule
Extends from behind the teeth and gums to the opening of the pharynx
Oral Cavity
Function of Mouth and oral cavity and buccal cavity
Ingestion, Mechanical Digestion, Food preparation
What do the lateral walls of the mouth form?
Cheek