Histology of Accessory Organs Flashcards
What is the flow of saliva?
acinus –> intercalated duct (low cuboidal epi) –> straited duct (simple cuboidal to columnar epi) –> excretory duct (simple cuboidal to pseudostrat columnar or stratified cuboidal)
What does mucous acini produce?
thick glycoprotein rich product
What does serous acini produce?
water based product
What is the structure of mucoserous acini?
core of mucous cells surrounded by serous Demilune
Where are myoepithelial cells found? What do they assist in?
located between epithelial cells and basal lamina
moving secretory products toward the excretory duct
What kind of acini does the parotid gland have?
serous
What are the cellular features of the parotid gland?
Pyramidal cells with basally located nucleus, prominent RER in basal region, secretory granules visible in apical region
What are the features of the sublingual gland?
Branched tubule-alveolar gland with serous and mucous cells (but predominatly mucous), lacks defined capsule but is divided by CT into small lobes, intercalated and striated ducts are poorly developed
What kind of cells does the submandibular gland have?
Mucous cell have acini that are capped by serous demilunes
Serous secretions controlled by myoepithelial cells
What is the job of the exocrine component of the pancreas? What is its functional unit?
synthesizes/secretes enzymes essential for digestion in intestine
Serous acinus which contrains acinar cells
Where are the intercalated ducts of the exocrine pancreas? What do they secrete?
within acinus cetroacinar cells, continuous with low cuboidal of intercalated
HCO3-, Na+ and H20
What is the role of pancreatic acinar cells?
Have apical domain of zymogen granules which have pancreatic proenzymes, adjust levels based on diet (high carb then amylase, high protein then proteases)
What is the role of the endocrine component of the pancreas?
synthesizes/secretes hormones (insulin and glucagon) into blood –> regulation of glucose, lipid, and protein metabolism
What do the islets cells of the pancreas produce?
alpha= glucagon
beta= insulin
gamma= somatostain
pp cells= pancreatic polypeptide
What encloses the liver?
thin CT capsule line with mesothelium of visceral peritoneum lacking where directly adheres to diaphragm
What is the job of hepatocytes?
Secrete bile mixture of H2O bile salts and pigments phospholipids
Drains into bile canaliculus, canal lined with cholangiocytes located btwn adjacent hepatocytes, canaliculi join to eventually contribute to biliary tree
What is the function of bile?
fat absorption, excretion, cholesterol, bilirubin, iron, copper
What are the functional units of the liver?
hepatic lobule= histo
portal= bile and exocrine function
liver acinus= blood flow and O2 content
What are hepatic lobules?
Organization of liver parenchyma, form irregular plates radiating from central vein which are supported by a stroma of reticular fibers, plates separated by sinusoids (discontinuous)
Does blood and bile flow in the same direction?
NO opposite
What do the peripheral angles of hepatic lobules contain?
portal triad in fibrous CT= venule branch of portal vein rich in nutrients low in O2, arterioles from hepatic a. which supply O2, and bile
What are hepatic sinusoids?
anastomosing capillaries that perfuse hepatocytes with portal and arterial blood
What are Kupffer cells?
stellate macrophages within endothelium of sinusoids, larger than endo cells, detect and phagocytose effete erythrocytes, distinguish hepatic sinusoids
What are stellate macrophages?
small lipid droplets that store Vitamin A and other fat soluble
