GI SYSYEM I Flashcards
what are 7 major functions of GI system
- ingestion
- mechanical processing
- compaction
- digestion
- secretion
- absorption
- excretion
what is mechanical processing
break down of food into smaller molecules
what is compaction
dehydration of undigested material and waste into feces
what is digestion
break down of macromolecules
what is responsible for digestion
- chemicals
2. enzymes
what is responsible for secretions
accessory organs
what do accessory organs secrete
- acids
- enzymes
- buffers
when does absorption occur
after digestion
what is absorption
movement of nutrients from tube to blood
what does nutrient rich blood pass through
liver
what happens to nutrient rich blood after passing through liver
passes through heart
what happens when nutrient rich blood passes through heart
nutrient rich blood becomes oxygenated
HISTOLOGY OF DIGESTIVE TRACT what are 4 basic layers all throughout the tube
- mucosal
- submucosal
- muscularis externis
- serosa
HISTOLOGY OF DIGESTIVE TRACT what is function of serosa layer
produce watery fluid for lubrication
HISTOLOGY OF DIGESTIVE TRACT what is histology of glandular tissue / acessory organs
epithelium
HISTOLOGY OF DIGESTIVE TRACT where do secretions of exocrine glands go
tube
HISTOLOGY OF DIGESTIVE TRACT where do secretions of endocrine glands go
- circulation
- surrounding CT
MUCOSA what is mucosal layer made of
epithelium
MUCOSA why is mucosa made of epithelium
lumen
MUCOSA what is purpose of having stratified squamous epithelium at beginning and end of tube
associated w outside world
MUCOSA what kind of epithelium are in parts of tube within abdomen
simple squamous epithelium
MUCOSA what is purpose of simple squamous epithelium in abdomen
absorption
MUCOSA what does epithelium always require
source of vasculature
MUCOSA what is source of vasculature for epithelium
lamina propina (CT)
MUCOSA what are glands of mucosa layer filled w
mucous
MUCOSA what is function of mucous
lubrication
SUBMUCOSA what is submucosa
CT
SUBMUCOSA what is function of submucosa
act as passageway for
- vasculature
- nerves
- lymphatics
SUBMUCOSA what is present in submucosal layer (3)
- immune cells
- exocrine glands
- specialized plexus
SUBMUCOSA what is function of specialized plexus
- innervate mucosal layer
- innervate submucosal layer