Small Intestinal Disorders and Investigations Flashcards
What is digestion?
Breaking down of food into its components
What is absorption?
Passage of nutrients into the body
What are the functions of the small intestine?
Digestion
Absorption
Endocrine and neuronal control (flow of material from stomach to colon)
Barrier functions
When is the full length of the small intestine reached?
Usually by age 11
What is the average length of the small intestine?
2.5-4.5m
What allows the small intestine to have such as large surface area?
Villous architecture
Constant turnover of cells in crypts and villi
Why does the small intestine have a low bacterial population?
Toxic environment due to digestive enzymes, bile salts and IgA
What does maintaining control of digestion require?
Lots of fluid
Controlled hydroplysis to avoid fluid shifts
Sophisticated control of motility
Absorption against gradients
Onwards processing in the liver
What enzymes are in the stomach for digestion?
Salivary amylase
Pepsin
Why must digestion in the stomach be controlled?
Avoid osmotic shifts
What are proteins broken down into?
Oligopeotides and amino acids
What enzymes control the breakdown of protein?
Trypsin and chymotrypsin
What enzyme controls the breakdown of fat?
Pancreatic lipase
What is fat broken down into?
Glycerol and free fatty acids
What enzyme controls carbohydrate breakdown?
Pancreatic amylase
What does pancreatic amylase break carbohydrates down into?
Disaccharides
What does the final digestion of carbohydrates?
Brush border disaccharidase
What are symptoms of small intestine disorders?
Weight loss
Increased appetite
Diarrhoea
Sometimes steatorrhoea
Bloating
Fatigue
What is steatohoea caused by?
Fat malabsorption
What is poo like for someone who has steatorrhoea?
High fat content
Stool less dense and floats
Pale
Foul smeeling
May leave an oily mark or oil droplets
What are signs of small intestinal disorders?
Signs of weight loss such as low or falling BMI
What are some examples of possible vitamin/mineral deficiencies?
Iron
B12
Ca2+, Mg2+
D
B9 (folate)
A
K
B complex
C