Nutrient Absorption and Pathophysiology of Malabsorption Flashcards
Where is the site of digestion and absorption in the GIT?
Small intestine
What kind of transporters in the small intestine are used for amino acids?
Sodium-linked transporters
Protein absorption throughout the small intestine:
About 50% of protein is absorbed by the end of the duodenum. About 70% by the end of the jejunum and a bit more (90%) by the distal ileum.
Which transporter on the apical surface of enterocytes is responsible for transporting fructose
GLUT5 (slow facilitated diffusion)
Which transportes allows sugar monomers (glucose, fructose and galactose) to move out of the enterocyte into the bloodstream?
GLUT2
Lactose is a disaccharide composed of:
glucose and galactose
Sucrose is composed of:
glucose and fructose
Maltose is composed of:
2 glucose molecules
By the time you get to the mid ileum, the percentage of glucose absorbed is:
100%
Some lipids are only digested through enzymic hydrolysis only and do not require emulsification.
These types of lipids are:
Esterified medium chain fatty acids (found in dairy products)
The two functions of micelles:
- Solubilize cholesterol in the bile
2. Carry the products of fat digestion in the small intestine to the brush border for absorption
What percentage of fat in the diet is lost in the stool:
2 - 4%
If both bile salts and pancreatic lipases are both absent i.e. if biliary and pancreatic functions are absent, there will still be SOME fat absorption due to the presence of:
lingual lipase
Measuring the amount of fat in the feces is a good indication of:
Malabsorption (Patient has to be put on a strict diet prior to measurement as the fat content of their diet should be known)
What types of anemia can occur in sprue (celiac disease):
microcytic and macrocytic anemia due to malabsorption of iron and vit B12 (respectively)
