PHYS 3 Digestion and absorption in the GI tract Flashcards
structure of intestinal mucosa
ideal for?
lumen of small intestine arranged in?
what else increase surface area?
longest in?
what is brush border?
site for?
barrier for?
cell types of intestinal epithelium
(3)
E- function? turnover? susceptible to?
GC- secrete what? this does what?
PC- do what?
routes of passage into enterocytes?
Major mechanism for uptake of protein?
other 3?
solutes moving across enterocyte encounter?
some of the layers?
adaptations in digestion maintain?
in certain problems such as small bowel resection their are adaptions that allow things to continue smoothly. Adaption though is limited such as vit B12 absorption with a terminal ileum resection
genetic abnormalities also exist that distrub adaptability
major sugars in human diet?
primary?
secondary?
cellulose?
carbohydrate digestion locations?
enzyme?
starch goes to?
Maltose goes to?
trehalose to?
lactose?
sucrose?
enzymes?
Absorption
what mechanisms?
what creates concentration gradient?
glucose transporter? type of transport?
fructose? type of transporter?
galactose transporter? type?
Into the blood transporter?
know important transporter for galactose absorption
lactose intolerance
what is it?
caused by?
this holds what in lumen? causing?
ferments into?
test of CHO assimilation
how?
should pee out how much?
protein digestion
types of enzymes? (2)
what does each hydrolyze?
example of each?
protein digestion
locations
S: what is secreted here? activated how?
how much % protein breakdown?
essential?
protein digestion
locations
P: breaks proteins into?
enzymes?
each does what?
protein digestion
locations?
SI: enzymes?
what are absorbed into enterocytes?
Protein digestion
pancreatic zymogens
activated by?
protein absorption
type of transporter for AA?
for di and tri peptides?
into the blood how?
Deficiency of pancreatic enzymes or defect in transporters of intestinal epithelial cells?
(5)
Chronic pancreatitis and cystic fibrosis
cause?
Congenital trypsin absence?
why?
all gone since trypsin needs to activate others
Cystinuria
caused by?
Hartnup disease
whats the problem?
symptoms resemble?
recessive dom?
symptoms?
Cystic fibrosis
whats the problem?
fat digestion
complicated by?
what emulsify?
Fat digestion
locations?
S: what enzymes?
what emulsifies here?
% TAG digestion?
what allows more time in stomach?
stomach
small intestine
Fat digestion
SI: % lipid digestion?
what emulsify?
what completes digestion?
fat absorption steps
1-5
lack of what leads to no lipid absorption?
problems arise where?
these can all lead to?
Pancreatic enzyme secretions
- Bile acid secretion
- Emulsification
- Micelle formation
- Diffusion of lipids into intestinal epithelial cells
- Chylomicron formation
- Transfer of chylomicrons into lymph
lead to Steatorrhea
failure to secrete proper amounts of pancreatic enzymes?
Zollinger-Ellison?
Pancreatitis? impaired what secretions?
One overlying theme?
deficiency of bile salts
interferes with?
factors that cause a deficit?
(2) why?
loss or decreased number of intestinal epithelial cells is called what?
cause?
reduced?
what is impaired?
nutritional deficiencies?
major symptom?
treatment?
Celica sprue
what is it?
type of disorder?
malabsorption related to?
most common in?
symptoms?
management?
Small intestine bacterial overgrowth
what is it?
symptoms?
result in?
enzymes that are messed up?
test for it how?
vitamin absorption
Fat-soluble
how?
water-soluble
how?
except? this is how?
vitamin B12
functions
metabolic functions?
coenzyme?
cofactor?
pernicious anemia caused by?
other heme disorders due to vitamin B12 deficiency?
pernicious anemia
stomach does not produce enough?
common causes?
surgical implications of vitamin B12 absorption
two procedures that can affect vitamin b12 absorption?
Calcium absorption
depends on presence of?
absorbed across what?
in small intestine?
what also govern calcium absorption?
vitamin D absorption
defficiency results in?
can cause?
how absorbed?
iron absorption
liver secretes? into what?
enters?
what binds iron? what else forms?
this gets uptook how?
Fe absorption schematic
generally what gets absorbed?
unique in a specific part?
only thing in graph that is not just small intestine in
ileum for bile salts and water-soluble vitamins/b12
