digestion and absorption part 1

Question 1

what is basic structure of intestine

Answer 1

efficient absorption requires a large surface area
created by its length- small intestine is around 6cm long
the presence of deep, circular folds of mucosa submucosa

Question 2

what are villi

Answer 2

0.5-1.5mm high and increase surface area by 10 fold

Question 3

what are microvilli

Answer 3

enterocytes that are 1 micrometer long and 0.1 micrometer in diameter, increase surface area by 20 fold
estimated surface area for absorption is 200m^2

Question 4

what is malabsorption syndrome

Answer 4

number of disorders in which the intestines ability to digest and absorb certain nutrients and fluids is affected

Question 5

what is the pathalogical mechanism
intraluminal
intestinal
post epithelial

Answer 5

intraluminally-impaired digestion (bacterial overgrowth or pancreatic insufficiency)
intestinal-structural changes (coeliac disease or surgical resection)
impaired brush border hydrolase activity (lactase deficiency)
impaired transporter activity- glucose galactose malabsorption
postepithelial- obstruction of lymphatic system

Question 6

what can cause modifications of villi and cause malabsorption

Answer 6

coeliac disease (caused by gluten intolerance)
moderate villus atrophy
complete villus atrophy

Question 7

what are the free factors that determine absorption

Answer 7

surface area of intestine
extent and location of uptake
transport route and protein properties

Question 8

how much nutrients and water are absorbed a day

Answer 8

8-10 L
1kg nutrients per day