Chapter 11: Digestive system Flashcards
digestive tract runs from …
mouth to anus
the GI tract is a specialized tube that allows the body to ?
gain nutrients from the outside environment
most nutrients must be broken down and processed by ____ and ____ methods.
biochemical and mechanical methods
digestive organs and accessory organs play a role in breaking down what?
large polymers such as carbs fats and proteins into smaller monomers
onced reducted to simple building blocks, absorption across the gut wall happens and the distribution to the body’s cells via ____.
via the circulatory system
food that cannot be broken down by the digestive system is excreted as waste and represents what?
a missed opportunity to gain nutrients
in a healthy adult how long is the GI tract?
Why does it appear longer in cadavers?
30 feet in length
-due to loss of muscle tone
GI tract walls : what are the four layers?
mucosa, submucosa, muscularis externa, and serosa
highly specialized cells are present generally in what layers of the GI tract?
mucosa and submucosa this allows different areas to accomplish very specific biochemical processes (enzymes assist with this)
what do enzymes help with
the breakdown of food
if food moves too fast through the GI tract what happens?
the body is unable to efficiently extract nutrients from it before it gets excreted
if food moves to slow through the GI tract what happens?
can cause extreme discomfort and lead to serious disorders
what is the flow of breakdown and absorption of nutrients
- ingestion of polymers
- breakdown of polymers
- propulsion
- absorption
- storage and defecation
