Digestion & Absorption Flashcards
What is the alimentary tract?
digestive tract
What is bolus?
what food turns into following chewing
What enzymes help break down food?
amylase (protein) and lipase (fat) pepsin (protein)
What cells are present in the stomach to help break down?
chief cells, parietal cells, mucous cells, G cells
What is the purpose of chief cells?
-Secretes lipase which breaks down fats.
-Releases pepsinogen
What is the purpose of parietal cells?
-Secretes intrinsic factor
-Releases HCL, which is needed to convert pepsinogen to pepsin (to then breakdown proteins)
What is the purpose of intrinsic factor?
Needed for the absorption of B12 and HCL
What is the purpose of mucous cells?
-release mucus to protect stomach lining
-lubricates
-protect stomach lining
What is the purpose of gastrin?
Signals the release of HCL
What part of the small intestine is the primary part for nutrient absorption?
jejum and ileum
What is the last stop for food in the small intestine?
duodenum
What stimulates the release of secretin?
duodenum
When fat and protein enter the duodenum what is stimulated?
cholecystokinin
The presence of cholecystokinin in the duodudeum causes what?
It triggers the gallbladder and pancreas to contract, which then causes bile to be released. This way bile can combine with the food to turn into absorbable nutrients.
What is required for trypsin activation?
enterokinase
What are extozymes produced by?
enterocytes
What is the purpose of pancreatic bicarbonate?
Can decrease HCL into a weaker acid
Bile is stored in____and released by____
-stored in gallbladder
-released by liver
What water process is used to move nutrients through digestion?
osmosis
What is passive diffusion?
high concentration to low concentration
What uses passive diffusion?
lipids
What is facilitated diffusion?
has a protein attached to transport
What uses facilitated diffusion?
carbohydrates
What is active transport?
low concentration to high concentration
What uses active transport?
proteins
What is the purpose of the intestinal barrier?
not allow any foreign or bad organisms into the gastrointestinal areas or the portal vein
What is the purpose of GALT?
first line of defense against foreign cells. It releases SIgA to support in this process.
What test is used to determine status of mucosal barrier?
lactulose test
What is glutathione?
-an intestinal anti-oxidant
-can help breakdown foreign products in digestion
-does not need B12 to do this
What fuels enterocytes?
glutamine
What happened in glutamine levels are low?
-cell death
-decrease in digestion ability
What is the role of the large intestine?
-reabsorb water
-fermentation of dietary fiber
What is the purpose in the fermentation of dietary fibers in the large intestine?
What are examples of soluble dietary fiber?
-beta-glucans
-ex: pectins, gums
How much dietary fiber do we need daily?
25-35 g
What are non fermentable fibers?
oats
What does the nervous system release to support the digestive process?
actetylcholine
What is the most common form of carbohydrate malabsorption?
lactose intolerance
What is the common form of protein malabsorption?
celiacs disease
What protein are individuals intolerant of if they have celiacs disease?
gliadin
What is the protein factor gliadin found in?
-wheat
-rye
-barley
What diet does and individual with celiacs disease follow?
gluten free
Fat malabsorption shows the following symptom?
steatorrhea
What is GERD?
burning sensation or acid reflux
What condition is connected to GERD?
obesity
What causes secretory diarrhea?
-vital infections
-drugs
What causes osmotic diarrhea?
-alcohol
-lactose intolerence
What areas are affected by Crohn’s disease?
any part of the digestive tract
What areas are affected by ulcerative colitis?
the colon
Cohn’s disease can lead to malabsorption of this major nutrient?
fat and fat soluble vitamins
Increase in this type of acids has shown to cause IBD?
linoleic acid
What is necessary for antimicrobial defense?
secretion of GALT and SIgA
If the intestinal barrier is harmed what needs to be supported?
GALT
What is the major intestinal antioxidant?
glutathione (GSH)
What is the fuel source for enterocytes?
glutamine