Lec 32 Flashcards
GI tract in order
1- oral cavity
2- esophagus
3- stomach
4- small intestine
5- large intestine
6- rectum
IS GI internal/external
Gi is hollow tube which anything inside is external environment
accesory gland helping GI
salivery glands
liver
gallbladder
pancreas
accesory gland can help but–
material does not pass through them
sphinctors
ring of smooth muscles
one-way valves tonically constricted until receive an order
— and — have major role in determining how lung should food be in stomach
protein and lipid
name sphinctors from beginning to rectum
1- upper esophageal
2- lower esophageal
3- pyloric
4- ileocecal
5- internal and external anal
upper esophageal sepparate
oral cavity and esophagus
lower esophagela separate
esophagus and stomch
pyloric separate
stomach and small intestine
ileocecal separaet
small and large intestine
internal anal is
Involuntarye
xternal anal is
Voluntary
wall of GI tract through stomach and small intestine from it lumen
1- mucosa: epithelial
2- submucosa
3- muscularis externa: circular and longitudinal muscles
4- serosa: connective
mucosa comprised of
epithelium
lamina propia
muscularis mucosae
epithelium
line the lumen
single layer epithelium
-transporting cell,secretory cell,stem cell
lamina propia
loose connective tissue
gland,lymph,blood supply
muscularis mucosae
thin layer smooth muscle separate mucosa from submucosa
submucos
loose connective tissue
nerve, blood supply,lymph vessel
submucosa intestine has
submucosal plexeus
part of ENS
Muscularis externa
2 layer smooth muscle
inner: circular layer–segmental mix and match–constrict lumen
outer: longitudinal layer–peristalsis–transporter–shorten tract
stomach additional 3rd layer oblique layer below submucosa
myenteric plexus (ENS) between inner and outer
Serosa
outer covering
continous to peritoneal membrane
has secretory epithelium+connective tissue
lubricate,protect
structure in Gi is related to
function
GI 4 processes
1- secretion: from cells into lumen or ECF
2- digestion:chemical/mechanical
3- absorption: lumen to ECF
4- motility: as muscle contraction
motility is by —- and —- contraction
peristaltic and segmental
peristaltic contraction
circular muscle contract behind the bolus to push forward
important for motility
segmental contraction
in small intestine
mixing contents and increase exposure to enzyme
important for mechanical digestion
GI secretion
Na, K, Cl, H and water
digestive enzyme
mucus
bile
brain of the gut is —
ENS
Ens can operate without input from
CNS or PNS
ENS regulate
motility and secretion
ENs is modulated by
ANS
regulation of Gi function
1- short reflex
2- long reflex
3- GI peptide
short reflex
integrated in ENS
occur entirely in gut wall
sensory receptor send info through interneurons
long reflex
inegrated with CNS
may originate in or out of GI
feedforward and emotional reflexes are initiated entirely outside of GI tract cephalic reflexes
GI peptide
secreted in short and long reflexes or independently
signalling molecules that alter GI secretion and motility
