3: Glands of Digestion Flashcards
Where is the gallbladder found?
small organ, inferior to liver
Where does the cystic duct connect to the gallbladder?
to the narrow neck
What are the functions of the gallbladder?
store bile
concentrate bile
What is hepatic bile?
PRIMARY BILE from the liver
What is cystic bile?
concentrated bile from the gallbladder
How is bile release controlled?
CCK and the Vagus nerve
What is the surface epithelium of the gallbladder?
simple columnar
What are the cell types found in the surface epithelium of the gallbladder?
Clear cells and Brush cells
What are the clear cells of the gallbladder?
CHOLANGIOCYTES
have many microvilli
fxn: concentrate bile, absorbs water
What are the brush cells of the gallbladder?
few in number
fxn: produce mucinogen
What is the lamina propria of the gallbladder like?
loose and very vascular ct
What kind of cells are found in the lamina propria of the gallbladder’s neck?
small mucus glands: lubricates the narrow neck lumen
Is the muscularis mucosa present in the gallbladder?
no
What is unique about the gallbladder’s submucosa?
ABSENT!!!!!!****
What is the patterning of the muscularis externa of the gallbladder?
NOT normal: thin smooth muscle layer w/ a disorganized muscle arrangement
What is the gallbladder’s serosa/adventitia arrangement?
MOSTLY serosa but some adventitia where is attaches to the liver
What is the endocrine pancreas?
“pancreatic islets” “islets of Langerhans”
produces hormones
What is the exocrine pancreas?
SEROUS ACINI producing digestive enzymes
What is the largest portion of the pancreas?
exocrine portion
How are the serous (pancreatic) acini controlled for secretion?
CCK and acetylcholine from parasympathetic nerves
secreted in response to food
How are the pancreatic ducts controlled for secretion?
secretes: H2O and HCO3
Controlled by: SECRETIN and acetylchoine from parasympathetic nerves
Where are centroacinar cells found in the pancreatic ducts?
located next to the acinar cells
What do the CENTROACINAR CELLS and cuboid cells produce?
in the intercalated pancreatic ducts they produce an ALKALINE FLUID w/ large amounts of bicarbonate ions
Where is the alkaline fluid and bicarbonate ions released into?
the duodenum to buffer stomach chyme
What is the function of the collagen-rich ct of the pancreatic ducts?
wraps the ducts: provides extra protection from the possible leakage of digestive enzymes
What is the largest gland in the body?
Liver
What are the general functions of the liver?
metabolism; production of blood proteins, factors, non-essential vitamins; detox blood; produce hepatic (primary) bile (exocrine fxn); store certain vitamins (vit. A & B12)
Why are the hexagonal shaped lobules of the liver hard to distinguish in humans?
due to lack of CT between lobules
What is the primary cell type in the liver?
hepatocytes
What are hepatocytes?
microvilliated cuboidal cells possessing lateral bile canaliculi between adjacent hepatocytes
What do the bile canaliculi do?
they collect bile
What is the flow of bile through the liver?
bile moves from the hepatocytes towards the bile duct branch in the portal triad
What is another name for Kupffer cells?
stellate macrophages
What are Kupffer cells?
resident macrophages
What do Kumpffer cells develope from?
monocytes
What is the function of Kumpffer cells?
phagocytosis of debris & aged RBC’s; act as an APC
What are Ito cells?
hepatic stellate cells
What is the function of Ito cells?
store lipids for immediate use; store vit. A; produce collagen I, III, IV and growth factors
What are pit cells in the liver?
natural killer cells (immune fxn)
What are hepatic progenitor cells?
likely present; responsible for regenerative capabilities
ALLOWS LIVER TRANSPLANT
What is included in the portal triads?
branches of the:
hepatic artery
portal vein
bile duct
What are hepatic sinusoids?
dilated, fenestrated thin walled vessels found between the rows of hepatocytes; carry a mix of venous (75%) and atrial blood (25%)
What is the central vein of the liver?
fenestrated thin walled vessel that collects blood from the hepatic sinusoids
What is the flow of the blood through the liver?
blood flows from the portal triad towards the central vein
What is another name for the space of disse?
Parisinusoidal space
What is the space of disse?
space between the hepatocytes and the fenestrated hepatic sinusoids
What is the function of the space of disse?
It allows direct contact of blood with the hepatocytes and they slow the blood flow down for interaction
ALLOWS LIVER TO TAKE OVER FOR SPLEEN ~24-48 hrs
What is glisson’s capsule?
surrounds the liver, covered with serosa
What is glisson’s capsule made of?
dense irregular CT
Can other CT be found in the human liver?
no, it’s limited
