Hydrolytic Digestion Flashcards
Name the 2 sites of hydrolytic digestion
luminal digestion
brush border digestion
What is digested in luminal digestion?
carbohydrates
proteins
lipids
What is digested in brush border digestion?
maltose
peptides
monoglycerides
Explain carbohydrate digestion
carbohydrates broken down to monosaccharides - starch, glycogen, sucrose, fructose, lactose, trehalose
Name the 4 signs of carbohydrate malassimilation
fluid diarrhea
weight loss
borborygmus (gas noise in stomach)
flatulence
Name some disorders of luminal maldigestion characterized by carbohydrate malassimilation
exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
Name some disorders of brush border maldigestion characterized by carbohydrate malassimilation
exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
small intestinal mucosal disease
disaccharidase defficiency
Name some disorders of membrane malabsorption characterized by carbohydrate malassimilation
small intestinal mucosal disease (IBS)
Explain protein digestion/absorption
stomach: proteins broken down to amino acids and oligopeptides by trypsin
small intestine: protein broken down to amino acids, oligopeptides, and tripeptides by enzymes (trypsin, elastase, etc.)
Name the 2 signs of protein malassimilation
weight loss
+/- diarrhea
Name some disorders of luminal maldigestion characterized by protein malassimilation
exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
Name some disorders of brush border maldigestion characterized by protein malassimilation
exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
food allergy/sensitivity reactions
Name some disorders of membrane malabsorption characterized by protein malassimilation
intestinal lymphangiectasia
gastrointestinal neoplasia
gastrointestinal ulceration
Explain lipid digestion/absorption
triglycerides are broken down into monoglycerides and fatty acids by lipases, hydrolases, and phopholipases
Name the 3 signs of lipid malassimilation
steatorrhea
malodorous feces
weight loss
Name some disorders of luminal maldigestion characterized by lipid malassimilation
exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
biliary obstruction
gastrinoma
Name some disorders of brush border maldigestion characterized by lipid malassimilation
exocrine pancreatic insufficiency small intestinal bacterial overgrowth duodenitis jejunitis ileitis
Name some disorders of membrane malabsorption characterized by lipid malassimilation
intestinal lymphangiectasia
biliary obstruction
Name the 4 prerequisites for fermentative digestion
reservoir for retention of ingest and microbes
oxygen content must be low (anaerobic environment)
acidity; suitable pH range (6-7)
removal mechanism for end products
Explain the anaerobic environment of fermentative digestion
colonic bacteria are strict anaerobes
oxygen introduced in food and water diffuses across foregut epithelium, used by facultative anaerobes
What are the substrates and end products of fermentative digestion
carbohydrates - VFA + CO2 + CH4
proteins - ammonia + keto acids
lipids - fatt acids + propionate
microbial cells - anaerobes
In cat and dog, what area of GI tract has the most fermentative capacity?
colon
Explain succession ecology of the GI tract
there are increasingly more bacteria in the ileum and large intestines than anywhere else because there is more breakdown occurring in those areas
