Gastrointestinal system Flashcards
Rebecca
what is the primary function of the GI tract
absorption of dietary nutrients maximised by secretions added to convert large molecules to smaller ones
what are the other GI functions
storage and secretion
what is the mucosa made up of and where is it found
epithelium, lamina propria, muscularis mucosa
nearest the lumen, inside
what is lamina propria
CT , has nerves, blood and lymph vessels
what is the muscularis mucosa
thin layer of smooth muscle
what is the submucosa layer and where
thicker layer with similar composition to lamina propria (CT)
contains submucosal plexus
middle
what is the muscularis externa
circular muscle, myenteric plexus and longitudinal muscle
what does the ENS do
coordinates contractions to mix and move contents between compartments
what is the serosa layer
outmost layer of CT and squamous cells
some tract sections dont have this layer
what 3 divisions of the ANS regulate the Gi function
parasympthetic
sympathetic
enteric
what does the PNS do
signals stimulate GI secretions and motility facilitating digestion and absorption of nutrients
what does the SNS do
decreases GI secretions and motility
how does the ENS work
can operate independenly and is involved with reflexes and majority of GI functions
what are the main plexuses in the ENS
myenteric
submucosal
what does the myenteric plexus do
motility
regulates intestinal smooth muscle , contractions of muscles
what is motility
coordinated contraction and relaxtion of muscles in the Gi tract
what does the submucosal plexus do
secretions, regulates secretions and local absoptive environment