M i c r o v i l l i Question

[lilyspetal]

Can someone provide an in depth explanation of microvili's function? Do they operate to increase cell surface area as needed and why would cell surface area need to increase? Thanks.

[Revenged]

disarracharide enzymes (i.e. maltase and sucrase) are produced only on the villi of the small intestine...

you need them to produce single sugar units - glucose, fructose - that can be taken up by diffusion/active transport into the bloodstream...

no villi occurs in coeliac disease - where gluten causes an autoimmune reaction to destroy the tissue... you get pretty much constant diarrhoea if you don't stick to a gluten free diet...

[MrMistery]

the cell surface area needs to increase in order for absorption to take place at a high enough rate. A protein transporter can only work so fast...
More about how microvilli form here:http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.figgrp.3025

[Darby]

There's so much more membrane on a microvilli-covered surface; if materials are moving across that surface, in or out, they'll move faster.