GI SYSTEM 2 Flashcards
STOMACH what is the function of stomach (3)
- mechanical processing
- digestion
- mix bolus and gastric juices
STOMACH how does stomach do mechanical processing
contracts muscles
STOMACH how does stomach do digestion
- secretes enzymes
- secretes chemicals
STOMACH what is chyme
mixture of bolus and gastric juices
STOMACH what is fundus
bony top of organ
STOMACH what is located in fundus of stomach
- air
2. cells that detect entrance of food
STOMACH what occurs in body of stomach
mechanical processing
STOMACH what is greater omentum attached to
greater curvature of stomach
STOMACH what are functions of greater omentum (2)
- deposit lipid
2. move to site of infection
STOMACH what kind of epithelium makes up mucosal layer
simple columnar epithelium
STOMACH what are 3 layers of smooth muscle in muscularis externis
- inner oblique
- middle circular
- outer longitudinal
STOMACH what does inner oblique layer contain
rugae
STOMACH what are rugae
folds
STOMACH what are gastric pits close to
lumen
STOMACH what is gastic gland close to
submucosa
STOMACH what layer are gastric pits + gastric glands a part of
mucosal layer
SECRETORY CELLS what is the function of surface mucosa cell
form thick layer of mucous to protect from HCl
SECRETORY CELLS what is the function of mucous neck cell
produce watery mucous
SECRETORY CELLS what is the function of parietal cell
produce HCl
SECRETORY CELLS what is the function of chief cell
produce pre-enzymes other than amylase
SECRETORY CELLS when do pre-enzymes secreted by chief cells become active
when they pass through mucous neck cell secretion
SECRETORY CELLS what is the function of neuroendocrine cell
produce gastrin
SECRETORY CELLS what is the function of gastrin
- stimulate parietal cells to produce secretions
2. stimulate chief cell to produce secretion
SECRETORY CELLS what cells are involved in protection
surface mucosa cell
SECRETORY CELLS what cells are involved in digestion (3)
- mucous neck
- parietal
- chief
SECRETORY CELLS what cells are involved in GI regulation
neuroendocrine
SI what kind of epithelium makes up mucosal layer
simple squamous epithelium
SI what is the main function of duodenum
digestion
SI what is the main function of jejunum
absorption
SI what is the main function of ileum
absorption
SI where does SI start and end
start = pyloric sphincter end= ileocecal valve of cecum
SI what quadrants can SI be found in
all 4
SI how is SI specialized for absorption
- contains folds
- each fold contains villi
- each villi contains micrtovillli
SI what is associated w each villus (2)
- vasculature
2. lymphatics
SI what 4 types of cells make up villar epithelium
- absorptive cell
- goblet cell
- enteroendocrince cell
- paneth cell
SI what is absorptive cell
main epithelial cell
SI what is the function of goblet cell
secrete mucous
SI what is the function of enteroendocrine cell
regulate (by releasing hormones)
SI what is the function of paneth cell
kill bacteria (to determine gut flora)
SI what do sugars get broken into
monosaccharides
SI what do proteins get broken into
aa
SI where do monosaccharide and aa go
hepatic portal circulation
SI what do fats get broken into
fatty acids ==> chylomicrons ==> chyle
SI where do fats go
lacteals
SI where does chyle go
thoracic duct
SI what surrounds most of SI
visceral peritoneum
SI what parts of SI not surrounded by visceral peritoneum
duodenum
DUODENUM what is function of duodenum (4)
- digestion of macromolecules
- receive chyme from stomach
- receive secretion from pancreas via gallbladder
- receive secretion from liver via gallbladder
DUODENUM where does digestion complete
duodenum
DUODENUM what glands does duodenum contain
brunner’s glands
DUODENUM where are brunner’s glands located
submucosal layer
DUODENUM what is the function of brunner’s glands
- provide mucous to neutralize acid from stomach
2. provide pancreatic buffers
LIVER what secretes bile
hepatocytes
LIVER what are canaliculi
channels
LIVER what happens to bile secreted by hepatocytes
go into canaliculi
LIVER what are 3 major functions of liver
- metabolic regulation
- hematological regualtion
- synthesis and secretion of bile
LIVER what is metabolic regulation referring to
- regulating what is absorbed by intestine
2. detoxifying what is absorbed from intestine
LIVER what is hematological regulation referring to
destroying
- aged RBC
- damaged RBC
- cellular debris
- pathogens
secreting plasma proteins
LIVER what is responsible for hematological regulation
macrophages
LIVER what is the purpose of secreting plasma portions
- osmotic function
- clotting function
- nutrient transport
LIVER what is bile involved in
lipid digestion
LIVER what makes up portal triad
- hepatic protal vein
- hepatic artery proper
3 common bile duct
LIVER what is portal triad associated w
lesser omentum
LIVER where does liver receive blood
intestines
LIVER what does blood from intestines contain
- nutrients
- toxic compounds
- pathogens
LIVER what is pathway of blood
1 periphery of liver lobules
- central vein
- L and R hepatic vein
- inferior vena cava
LIVER what mxed in sinusoids
- blood from hepatic portal vein
2. blood from hepatic artery proper
LIVER what is the purpose of blood mixing in sinusoids
provide hepatocytes with
- oxygen rich and
- nutrient rich blood
LIVER what are sinusoids
large vessels
LIVER what are kupffer cells
macrophages (for hematological regulation)
LIVER what does central vein fo to
- L hepatic vein
2. R hepatic vein
LIVER what surrounds liver lobules
sinusoids
LIVER what are hepatocytes
liver cells
LIVER what to hepatocytes make up
liver lobules
LIVER what are steps in bile flow
- canaliculi
- small biliary ducts
- larger ducts
- L + R hepatic ducts
- common hepatic duct
LIVER where is bile stored
gallbladder
LIVER what is bile released into to get into duodenum
- cystic duct
2. bile duct (cystic duct + common hepatic duct)
what does bile duct lead to
duodenum
GALLBLADDER what is the function of gallbladder
- concentrate bile
2. store bile
GALLBLADDER what does hepatopancreatic sphincter lead into
duodenum
GALLBLADDER what happens if hepatopancreatic sphincter closed
gallbladder fills w bile
GALLBLADDER what happens if hepatopancreatic sphincter open
duodenum fills w bile
GALLBLADDER what does chyme induce release of
CCK
GALLBLADDER what is the function of CCK
- induce relaxation of hepatopancreatic sphincter
2. induce contraction of gall bladder
PANCREAS what is the function of pancreas (2)
- secrete digestive enzymes for digestion in intestines
2. secrete bicarbonate buffer for neutralization of chyme
PANCREAS what kind of gland is pancreas
- endocrine
2. exocrine
PANCREAS what is responsible for endocrine secretions
islets
PANCREAS what do islets secrete
- glucagon
2. insulin
PANCREAS what is responsible for exocrine secretions
- acinar cells
2. centroacinar cells
PANCREAS what is the function of acinar cells
secrete pre-enzymatic digestive enzymes
PANCREAS what is the function of centroacinar cells
- secrete bicarbonate buffer
2. regulate release of pre enzymatic digestive enzymes from acinar cells
PANCREAS how do secretions from pancreas get into duodenum
pancreatic duct
PANCREAS what merges w pancreatic duct
bile duct
PANCREAS what does pancreatic duct enter duodenum from
hepatopancreatic ampulla
JEJUNUM what occurs in jejunum
majority of absorption
ILEUM what occurs in ileum
some of absorption
ILEUM what can be found in ileum
- ileocecal valve
2. lymph nodules
ILEUM what is ileocecal valve
valve connecting SI to LI
ILEUM what is the function of lymph nodules
protect SI from colonic bacteria
LI what are parts of LI (6)
- appendix
- ascending
- transverse
- descending
- sigmoid
- rectum
LI what are 3 functions of LI
- reabsorb water
- reabsorb electrolytes
- absorb vitamins produced by colonic bacteria
LI what is retroperitoneal
- ascending
- descending
- rectum
LI what is intraperitoneal
- cecum
- transverse
- sigmoid
LI what are 2 types of colic epithelial cells in mucosal layer
- absorptive cell
2. goblet cell
LI what is the function of absorptive cells
main colonic epithelial cells
LI what is the function of goblet cells
secrete mucous for lubrication
LI how is mucosal layer in rectum specialized
simple columnar epithelium
LI what is the function of rectum (2)
- store feces
2. move feces into rectal canal
ANAL CANAL how is mucosal layer in anal canal specialized
stratified squamous epithelium (not keratinized) to stratified squamous epithelium (keratinized)
ANAL CANAL what part of anal canal is autonomic
internal anal sphincter
ANAL CANAL what part of anal canal is somatic
external anal sphincter