Exam 3 – Lecture 25: GI 4 Flashcards
What is the difference between exocrine and endocrine?
Exocrine has ducts
Endocrine is ductless
What comes from exocrine secretions of the pancreas?
Digestive enzymes (acini, proteases, lipases, etc)
What comes from endocrine seccretions of the pancreas?
Metabolic hormones (inuslin, glucagon, somatostatin)
What do islets produce?
Insulin
Glucagon
Somatostatin
Describe the exocrine portion of the pancreas
Acini
Serous gland
Zymogen granules
Bicarbonate
What are the zymogen granules in the pancreas?
Trypsinogen Chymotrypsinogen Proteases, peptidases Lipases Amylolytic enzymes Nucleolytic enzymes
What is the control of the pancreas?
Neural and hormonal control
Describe the endocrine portion of the pancreas
Islets
“Diffuse” (not acinar)
What does the enodcrine pancreas do?
Mostly blood glucose control
What is involved in the blood glucose control of the endocrine pancreas?
α cells (glucagon)
β cells (insulin)
D cells (somatostatin)
What is the largest “gland” in the body?
Liver
What does the liver’s function primarily revolve around?
Metabolism of CHOs, lipids, protein production (serum), protein catabolism (NH3), vitamins, minerals, toxins, nd pharmaceuticals
What does the liver produce?
Bile, which is important in digestion
Describe the gross anatomy of the liver
Anterior abdomen
Lobes (vary with species)
Dual blood supply
What is the blood supply for the liver?
Hepatic artery (branch of celiac) 25% Portal vein (GI, pancreas, spleen drainage) 75%
What does the portal vein branch off of?
The abdominal cavity from the aorta
What are the constituents of the liver?
Parenchyma
Connective tissues stroma
Vessels
Perisinusoidal spaces
What are the lobules of the liver?
Classic
Portal
Acinar
What is the classic lobule centered around?
The central vein
What does the portal triad consist of?
Branches of the hepatic artery
Portal vein
Bile duct
What are sinusoids filled with?
Blood
What are sinusoids?
Spaces between hepatocytes
What shape are hepatocytes?
Cuboidal
What do hepatocytes form?
Anastomosing plates and cords
What do hepatocytes do?
High metabolic activity of the mitochondria, ER, golgi, lipid droplets, and glycogen in a hepatocyte
What are other cells of the liver?
Discontinuous epithelium
Kupffer cells
Stellate cells
What does discontinuous epithelium allow for?
Close contact with hepatocytes
What do kupffer cells do?
Immune surveillance
They are resident phagocytes of the liver
Next line of defense after lymph nodes
Describe stellate cells
Lipid laden
Involved in vitamin and lipid metabolism
What do adjacent hepatocytes form?
Bile canaliculi
Where is the first place bile goes when it leaves the hepatocyte?
Bile canaliculi
