Histology Of Accessory GI Glands Flashcards
What are the 3 main Digestive Glands
- Major Salivary Glands = associated with the oral cavity (parotid, Sublingual, Submandibular)
- Exocrine Pancreas = alkaline and enzymes into the duodenum
- Liver = Endocrine and Exocrine gland, access to blood
What is the organization of the Salivary Glands
CT tissue over it
Septa divides the gland in to lobes and smaller lobules
How are secretory cells in the salivary glands organized and how do they release
Organized into Acinus and make saliva
ANS and Myoepithelial cells control release
Order that the saliva travel trough to be released from gland
And type of cell it has
ACINUS—-> (ball shaped, Pyramidal)
intercalated duct——> (low cuboidal)
Striated Duct——> (simple cuboidal—-> simple columnar)
Excretory Duct (simple cuboidal —-> pseudostratified columnar + stratified columnar)
Parotid Gland Features
Serous Gland (serous secretory cells) Largest salivary gland, prominent RER(basal) + secretory granules (apical)
Submandibular Gland
Serous Cells mostly, some Mucous cells
Mucous cells: acini are capped by serous demilunes (bonnet)
shorter intercalated ducts
Longer striated ducts
What acini are capped by serous demilunes (bonnet)
Mucous Acini
Sublingual Gland
Mucous Acini mostly however some Serous Tubular branched glands No capsule, divided into lobes Poor intercalated and striate ducts You can see some Skeletal Muscle
Intralobular duct
Size of the acini
The Pancreas is mostly what type of gland
EXOCRINE, has endocrine also
EXOCRINE: make and secrete enzymes for digestion to the duodenum
ENDOCRINE: make and secrete Hs (Insulin and Glucagon) to blood = regulate glucose,lipids,protein metabolism
What type of acini glands do the Exocrine Pancreas have
How is it organized
What does it secrete
SEROUS acinus (pancreatic acinar cells) The CENTROACINAR CELL inside the acinus starts the intercalated duct (low cuboidal) = secretes HCO-3, NA+, H2O (Alkaline) all cells (except centroacinar and the intercalated duct stain dark)
Parotid vs exocrine pancreas
Has BVs
Has controacinar cells
What makes a Pancreatic Acinar Cell
Well developed RER + Golgi ZYGOMOGEN GRANULES (proenzymes)
Name the proenzymes that the granules of exocrine pancreas release
- Trypsinogen, chymotrypsinogen —-> PROTIENS
- Amylolytic enzymes(a-amylase)—-> CARBS
- Lipase —-> LIPIDS
- Deoxyribonuclease, ribonuclease—-> NUCLEIC ACIDS
High carb diet vs high protein diets and enzyme formation
Increases the enzyme needed
EX: high protein = high proteases made
ENDOCRINE PANCREASES looks like
The islets surrounded by reticular capsule surrounded by exocrine ducts
From endodermal outgrowth
a, B, g,PP
Liver is lined by
And glands are arranged as
And what cell type
Visceral peritoneum (mesothelium)
Arranged as CELLULAR CORDS (not acini)
Hepatocytes
Stores and makes BILE
Hepatocytes are shaped as
Large polygonal cells + microvilli
Many lysosomes and sER and Golgi
What is bile made of
H2O, Bile Salts Pigments Phospholipids Electrolytes Cholesterol (very little)
Bile function
Fat absorption
Excretion of Cholesterol, Iron, Cu, Bilirubin
Drains into Bile CANALICULUS (between the hepatocytes)
Hepatic Lobule
Drains blood from PORTAL VEIN + HEPATIC ARTERY ——> Central Vein or Hepatic Vein (middle of acini)
6 portal triads to central vein
Portal Lobule
Drains bile from hepatocytes (from central vein)——> to bile duct
Three central veins to one portal triad
Hepatic Acinus
Supplies oxygenated blood to hepatocytes
Two portal triads (when 2 hepatocytes connect) and give blood differently based on how far you are from the central vein of each hepatocyte
*most important for pathology and doctors usually
Gallbladder
Color is veryyy green
Stores and concentrates bile
Simple columnar + microvilli over Lamina Propria
Muscularis Externa present in irregular way
NO Muscularis mucosae
NO submucosa
EXTERNAL ADVENTITIA against the liver part (other parts are Serosa)
