GI ML: 1 Flashcards
What makes up the Gi Tract
-continuous tube from mouth to anus
- 7 sphincters of significance
What are the accessory organs of the gi tract
salivary glands, liver, gallbladder, pancreas
What is the order of the 7 spinchters?
- upper esophageal sphincter
- lower esophageal sphincter
- pyloric sphincter
- sphincter of oddi
- ileocecal valve
- internal anal sphincter
7/ external anal sphincter
Order of the digestive system
- mouth
- salivary glands
- pharynx
- trachea
- esophagus
- live
- gallbladder.
- stomach
- pancreas
- small intestine
- large intestine
- anus
What is the first layer of the GI wall
mucosa
What three things makes up the mucosa layer
epithelium, lamina propria, and muscularis mucosa
What is the job of the epithelium
surface area (villi) and secretions (crypts)
What is the job of the lamina propria
connective tissue
What is the job of the muscularis mucosa
thin layer of smooth muscle that makes flux and agitation
What is the second layer of the gi wall
submucosa
What are the two things that make up the submucosa
-major blood and lymthatic vessels
-submucosal plexus
What is the job of the blood vessels in the 2nd layer
vascular and lymphatic interface
What is the job of the submucosal plexus
ENS control of secretions
- can influence secretions of exocrine cells
What is the third layer of the gi wall
muscularis externa
What three things make up the third layer of the gi wall
-circular muscle
-myenteric plexus
-longitudinal muscle
What is the job of circular muscle
changes diameter
What is the job og the myenteric plexus
ENS control of muscle but aslo communicates with other plexus
What is the job of longitudinal muscle
changes length
What is the last layer of the gi tract and its job
serosa, connective tissue
What can override the ens
the autonomic nervous system but usually these two agree
What are the functions of the digestive system
-ingestion of foods and liquids containing nutrients and ions
-digestion of large molecules in foods and liquids in absorbable forms and then transport across the GI epithelium
-absorption of nutreints from the gut lumen into the internal envrionemnt (ecf)
-metabolic transformation of fuel molcules and detoxification of forign substances
-elimination of small amounts of end producys including bilirubin
- carrying out a variety of immune fuctions
What are the four processes of the digestive system
- motility
-digestion
-absorption
-secretion
motility
not just propel contents along but also mix and expose
digestion
breakdown both mechanically and chemically
absorption
small intestine dominates here
secretion
mucus throughout, notable secretions throughout
Amylase
breaks down big polysaccharides
Sucrase
breaks down sucrose
Lactase
breaks down lactose
Maltase
breaks down maltose
What are the protein enxymes
pepsin, trypsin, chymotrypsin, carboxypeptidase, aminopeptidase
What does pepsin, trypsin, and chymotrypsin break down
poplypeptides
carboxypeptidase and aminopeptidase break down what
peptide fragments
What does lipase break down
triglycerides
Why is the amount absorbed so much greater than amount consumed
secretions
Where do secretions come from
exocrine glands
How much water/ solids do we ingest a day
water: 1200mL and 500-800g of solids
How much is absorbed into the blood (small)
6700 ml
How much is absorbed into the blood (large)
1400ml
How much salivary secretions
1500ml
How much gastric secretions
2000ml
How much bile secretions
500ml
How much pancretic secretions
1500
How much intestinal secretions
1500ml
How much is excreted from the body
feces 100ml water and 50-100g of solids
