Term
| Absorptive area in SI is increased 600 x by: |
|
Definition
- folds in muscularis mucosa- 3x
- villi- 10x
- microvilli- 20x |
|
|
Term
| Unstirred layer of SI is called the ____. |
|
Definition
|
|
Term
| disaccharides and proteins get ___ in the lumen of the gut before they are absorbed by epithelial cells. |
|
Definition
|
|
Term
| Peptides undergo ___ ___once they are inside the epithelial cells. |
|
Definition
| - intracellular hydrolysis |
|
|
Term
| Triglycerides undergo ___ ___ into ___ and ___ ___, but once they are in the epithelial cell they undergo ___ ___. |
|
Definition
- luminal hydrolysis
- glycerol
- fatty acids
- intracellular resynthesis |
|
|
Term
| There are only ____ ___ in the circulation, no peptides. |
|
Definition
|
|
Term
| average American diet is ___ grams of CHO/day, which is ___% of calories. |
|
Definition
-300-500 grams
- 40-45% of calories from CHOs |
|
|
Term
|
Definition
- mouth: salivary alpha amylase digests starch to glucose and dextrins
- pancreatic alpha amylase: digests all starches to glucose
- In SI you have dissacharidases. |
|
|
Term
| 3 signals that initiate pancreatic alpha amylase to be secreted: |
|
Definition
- parsympathetic stimulation
- gastrin
- CCK (potentiated by secretin) |
|
|
Term
| alpha dextrinase breaks down alpha-limit dextrin into: |
|
Definition
- maltotriose
- maltose
- glucose |
|
|
Term
| Maltase breaks down maltotriose into: |
|
Definition
|
|
Term
| Maltase breaks down maltose into: |
|
Definition
|
|
Term
| Sucrase breaks down sucrose into: |
|
Definition
|
|
Term
| Lactase breaks down lactose into: |
|
Definition
|
|
Term
| monosaccharides absorbed by blood stream: |
|
Definition
- glucose
- fructose
- galactose |
|
|
Term
| Glucose and Galactose are absorbed into the intestine by a ____ ____ which requries ___. Then a ____ ____ takes it into the blood. On the basolateral membrane you also have the NaK ATPase taking 3 sodium out and putting 2 potassium in. |
|
Definition
- sodium cotransporter (SGLT1)
- ATP
- GLUT 2 Transporter |
|
|
Term
| Fructose is absorbed into intestinal cell by ___ ___ via a ___ ___, no ___ is needed. It is not known how it is tranported to the blood. |
|
Definition
- facilitated diffusion
- GLUT 5 transporter
- no ATP needed |
|
|
Term
|
Definition
- pectins
- mucilages
- gums |
|
|
Term
|
Definition
- cellulose
- hemicellulose
- ligins |
|
|
Term
| Fibers bind ___ and ___ transit time. They also ___ minerals such as __, __, __, and ___. They also ___ organic material like ___ __, ___, and ____. |
|
Definition
- water
- decrease
- adsorb
- calcium, iron, zinc, magnesium
- adsorb
- bile salts
- lipids
- cholesterol |
|
|
Term
| In the colon, fiber is digested by bacterial flora into ___ ___ ___ ___, which can be absorbed by the colon and ___ , which gets fermented to gases. |
|
Definition
- short chain fatty acids
- lactate |
|
|
Term
| Failure to absorb short chain fatty acids from fiber leads to ___ ___, this is how many laxatives work. |
|
Definition
|
|
Term
| If you have a brush border enzyme deficiency, can you still digest glucose? |
|
Definition
| yes, b/c you have salivary amylase and pancreatic amylase so starch digestion would be unharmed |
|
|
Term
| lactose intolerance can be due to lack of lactase or may be secondary to injury to intestinal mucosa such as: |
|
Definition
- Kwashiorkor
- Colitis
- Gastroenteritis
- Celiac and Tropical sprue
- excessive alcohol consumption |
|
|
Term
| average american diet has ___g/protein/day. Proteins get hydrolyzed into ___ common amino acids. B/c of variety many peptidases are required, they are: |
|
Definition
- 70-100g/protein/day
- 21
- pepsin
- pancreatic peptidases
- brush border peptidases
- epithelial cell/enterocyte peptidases |
|
|
Term
| Protein digestion begins in the stomach with ___ which breaks down proteins into ____ and ___ ___. Then ___ __ and ___ further breaks down proteins into ___ and ___ __. Then ____ in the ___ ___ of the SI break down everything to ___ __. |
|
Definition
- pepsin
- polypeptides
- amino acids
- pancreatic trypsin and chymotrypsin
- oligopeptides
- amino acids
- aminopeptidases
- brush border
- amino acids |
|
|
Term
| ___ a brush border enzyme, activates trypsinogen to trypsin, and then trypsin is able to activate all the other peptidases. |
|
Definition
|
|
Term
| There is specific amino acid transport into epithelial cells of intestine. There is also peptide transport into enterocytes, and then peptidases inside these cells break up the peptides into amino acids. |
|
Definition
|
|
Term
| If you are missing a specific transporter for an amino acid, does that mean you will lack that amino acid? |
|
Definition
| No, b/c that amino acid may be part of a di- or tripeptide that gets taken into the enterocyte and then broken down |
|
|
Term
| Amino acids are absorbed into the enterocyte via ___ ______ mechanism, just like ___ and ___. |
|
Definition
- active Na+-cotransport mechanism
- glucose
- galactose |
|
|
Term
| There are __ different amino acid and peptide tranpsort proteins in the luminal membrane. |
|
Definition
|
|
Term
| Di and tripeptides are absorbed into the enterocyte via a ___ ____. |
|
Definition
|
|
Term
| Average american diet contains ____ g/lipid/day. |
|
Definition
|
|
Term
| Fat is emulsified by ___ and ___ in the stomach. There is minimal digestion by ___ or ___ lipase. |
|
Definition
- acid and pepsin
- lingual or gastric lipase do very little digestion |
|
|
Term
| Bile salts are required for: |
|
Definition
- emulsification of fat in SI
- function of pancreatic lipases
- bile salts to transport micelles to surface of epithelial cells
- for fats to diffuse into epithelial cells while bile salt stays in lumen |
|
|
Term
| you can do without salivary and gastric lipase but you cannot do without pancreatic lipase. |
|
Definition
|
|
Term
| Glycerol ester hydrolase breaks down ___ into _____ and ___ ____ ___. |
|
Definition
- triglycerides
- 2 monoglycerol and free fatty acids |
|
|
Term
| Cholesterol ester hydrolase breaks down ____ ___ into ___ and ___ ____. |
|
Definition
- cholesterol ester
- cholesterol
- fatty acid |
|
|
Term
| Phospholipase A2 breaks down ___ into ____ and ___ __. |
|
Definition
- lecithin
- lysolecithin
- fatty acid |
|
|
Term
| fat soluble vitamins easily diffuse into epithelial cells. |
|
Definition
|
|
Term
| Once fats are in the enterocyte, they are ___ to form ___ in the ___ ___. They then aggregate into globules along with absorbed and newly formed ___ and ___ in the ___ ___ and get coated by ____. It is now called a ___. |
|
Definition
- recombined
- triglycerides
- endoplasmic reticulum
- cholesterol and phospholipids
- golgi apparatus
- apoproteins
- chylomicrons |
|
|
Term
| The chylomicron goes through ____ on the ___ membrane into the ____ ___, it then enters the blood circulation. |
|
Definition
- exocytosis
- basolateral
- lymphatic capillary |
|
|
Term
| Medium and small chain fats (10 c long) can ___ through epithelial cell into the ___ (40% of dietary lipids). |
|
Definition
|
|
Term
| Bile salts are absorbed in the ___ ___ by ___ ____. |
|
Definition
- terminal ileum
- sodium cotransport |
|
|
Term
| What all uses sodium contransport for absorption? |
|
Definition
- glucose
- galactose
- amino acids
- bile salts |
|
|
Term
| once chylomicrons are in the capillary they get hydrolyzed by ____ ____. this does not happen to short and medium chain fatty acids. |
|
Definition
|
|
Term
| conjugated bile acids are absorbed by sodium cotransport while uncongugated bile acids diffuse into enterocyte, they then go to portal blood and then the liver. |
|
Definition
|
|
Term
| SI absorbs 7 liters of water a day , proximal colon absorbs 2 liters/day |
|
Definition
|
|
Term
| Water absorptin in the small intstine occurs by ___ through pores b/w epithelial cells.85-95% is absorbed in upper portion of SI. It follows the osmotic gradient created by absorption of nutrients and electrolytes. |
|
Definition
|
|
Term
| If there is ____ chyme in the duodenum, you get osmosis of water INTO the lumen. |
|
Definition
|
|
Term
1-3 water ingested a day
7-10 liters secreted by the gut
only excrete 150-200 ml in feces |
|
Definition
|
|
Term
| The jejunum actively absorbs ___ and passively absorbs ___, ___, and ___. |
|
Definition
- sodium
- potassium, chloride, and bicarbonate |
|
|
Term
| The ileum actively absorbs ___, passively absorbs ___, and absorbs ___ in exchange for secretion of ___. |
|
Definition
- sodium
- potassium
- chloride
- bicarbonate |
|
|
Term
| Colon actively absorbs ___, secretes ___ when concentration in lumen is less than 25 mM, absorbs ___ in exchange for secreting ___. |
|
Definition
- sodium
- potassium
- chloride
- bicarbonate |
|
|
Term
| We absorbe 25-35 g/sodium/day. Mechansims for sodium absorption: |
|
Definition
- diffusion through sodium channel
- Na+H+ cotransport
- Na+Cl- cotransport
- Na+solute cotransport(glucose, galactose, amino acids, bile salts) |
|
|
Term
| Sodium is ___ transported out of the basolateral membrane into intercellular spaces. |
|
Definition
|
|
Term
| Chloride is absorbed by following the ___ gradient created by absorption of ___. There is ___ absorption in the ___ ___ and ___ ___ in exchange for ____. |
|
Definition
- electrochemical gradeint
- sodium
- active
- distal ileum
- large intestine
- bicarbonate |
|
|
Term
| potassium absorption is all around passive. |
|
Definition
|
|
Term
| Bicarbonate is ___ in the jejunum with Na+. It gets ___ ___ in the ___ ___ and ___ ___ in echange for chloride ions. |
|
Definition
- absorbed
- actively secreted
- distal ileum
- large intestine |
|
|
Term
| potassium is ___ absorbed through ___ junctions and lateral spaces. |
|
Definition
|
|
Term
| 25-80% of calcium is absorbed. It is absorbed through ___ transport and is absorbed relative to the body's needs according to ___ __ and ___ ___. |
|
Definition
- active
- vitamin D
- parathyroid hormone |
|
|
Term
| We ingest 15-25 mg iron, but only .75- 1.5 grams are absorbed. It is ___ transport based on body's needs. |
|
Definition
|
|
Term
| parathyroid's response to decreased calcium: |
|
Definition
| - low calcium> PTH converts vit. D to 25-OH-cholcalciferol in liver> small intestine epithlial cell> binding protein |
|
|
Term
|
Definition
|
|
Term
| gatric acid and ascorbic acid converts ferric (+3) iron to the ___ state. |
|
Definition
|
|
Term
| ___ is the carrier for iron into intestine. it binds to ferritin to get into enterocyte. |
|
Definition
|
|
Term
| Iron binds ___ in the blood and it is transported as ____. |
|
Definition
- transferrin
- apotransferrin |
|
|
Term
| iron gets transported where? |
|
Definition
- liver
- RBC's
- bone
- RE cells |
|
|
Term
| Iron gets stored as ____ in the ___, ___, and ___ ___. |
|
Definition
- apoferritin
- liver
- spleen
- bone marrow |
|
|
Term
| water soluble vitamins that are easily absorbed: |
|
Definition
| C, B1, B2, niacin, B6, biotin, folic acid, B12 |
|
|
Term
| B12 requries intrinsic factor from ___ ___ and is only absorbed in the ___ ___. |
|
Definition
- parietal cells
- terminal ileum
get low b12 if damaged parietal cells, don't eat b12, or no terminal ileum |
|
|
Term
| 1500 ml enter the colon, most of it absorbed, only ____ fluid in feces. |
|
Definition
|
|
Term
| proximal colon does ___ absorption of __ and ___ via electrochemical gradient and water via osmosis. |
|
Definition
- active
- sodium
- chloride |
|
|
Term
| Distal colon does active excretion of ___in exchange for ___. |
|
Definition
|
|
Term
| CHO, proteins, and lipids are mostly absorbed in the ___ and ___, very little in the ____. |
|
Definition
- duodenum and jejunum
- ileum |
|
|
Term
| Calcium, folate, and iron are absorbed in the ____, so without this you would get deficiencies.Eventualy another portion of the gut could adapt, but it would take a while. |
|
Definition
|
|
Term
| Bile acids and b12 are absorbed only in the ___. No part of the gut could adapt to this. |
|
Definition
|
|
Term
|
Definition
| throughout SI and proximal colon |
|
|
Term
| water soluble vitamins are absorbed in SI by: |
|
Definition
| - sodium dependent cotransport |
|
|
Term
| Fe+2 (ferrous iron) binds to ____ in the intestinal cell and ___ in the blood. |
|
Definition
- apoferritin
- transferrin |
|
|
