Outcome 11 - Gastrointestinal System Flashcards
what are the two groups the digestive system is organized into?
1) alimentary canal organs
2) accessory digestive organs
what are considered alimentary canal organs?
- mouth
- pharynx
- esophagus
- stomach
- small intestines
- large intestines
- anus
what are accessory digestive organs?
- teeth
- tongue
- liver
- gallbladder
- pancreas
- salivary glands
what is the definition for “alimentary canals organs”?
continuous tube that extends from mouth to anus
*have direct contact with food and liquids
what is the definition of “accessory digestive organs”?
organs that aid in the physical breakdown or chemical breakdown of food
what are the 6 digestive system processes?
1) ingestion
2) secretion
3) mixing and propulsion
4) digestion
5) absorption
6) defecation
what do GI cells secrete?
- ~7L of water
- acid, buffers
- enzymes
what is “mixing and propulsion”?
alternation between contractions and relaxations of the GI smooth muscles
what is “GI motility”?
mixing food with secretions and propelling them to the anus
what are examples of mechanical digestion?
- use of teeth to breakdown food
- stomach and small intestine churning and mixing it with digestive enzymes
what are examples of chemical digestion?
- digestive enzymes from mouth, stomach, pancreas, small intestine to aid in catabolism
what types of molecules are split by hydrolysis?
- cho, lipid, protein, and nucleic acid
what can be absorbed without chemical digestion?
- vitamins, ions, cholesterol and water
what is absorption?
- ingested and secreted fluids and ions enter the epithelial cells lining the lumen of the GI
- from cells lining gi to passing into the blood or lymph for circulation to the body
what is defecation?
the excretion of indigestible things, waste, bacteria, sloughed cells and materials that aren’t absorbed by feces
what tissues make up the walls of alimentary canals?
- mucosa
- submucosa
- muscular layer
- serosa
what is the mucosa?
it is epithelial tissue that comes into contact with food
- layer will change depending on where we are in the tube (i.e. oropharynx, laryngopharynx)
what are the three components of the mucosa?
- epithelium
- lamina propria
- muscular mucosae
describe the muscular mucosae?
- layer that gives the ridges throughout the whole lining of the mucosa
- layer that creates the contraction
what two types of muscles that make up the muscular layer of the alimentary canal?
- circular muscles
- longitudinal muscles
what is the difference between the circular muscles and longitudinal muscles?
circular = muscles/fibers are running around the circumference of the circle
long - runs parallel with the tube
what is the serosa made of?
areolar connective tissue and epithelium
* continuous of the layer of the peritoneum which lines the abdominal organs
what is the visceral peritoneum?
the serosa layer of the GI tract
what is the parietal peritoneum?
it lines the abdominopelvic cavity