Histology Glands Flashcards
Exocrine pancreas is a _____ gland involved in the production of _____ and _____ which are converted into active enzymes in the intestine.
Serious gland
Digestive enzymes (amylase and lipase)
Proenzymes (trypsinogen)
Secretory acini of the pancreas are _____ and are spherical in shape. Composed of a single type of cell, the ____ cell.
Serous
Pancreatic acinar cell
Centrally placed round euchromatic nucleus, large amts of basal RER, apical eosinophilic secretory granules. Basal part is basophilic, apical is eosinophilic creating a ____ appearance. Broad base and narrow apex leads to what shape?
Pancreatic acinar cells
Bull’s eye appearance
pyramidal
______ducts in the pancreas are located ____ the pancreatic lobule and begin from _____ the acinus.
Intralobular ducts
Within
Within
What are ducal cells found within the secretory acinus and are continuous with the intercalated duct cells?
Centroacinar cells
Intercalated ducts add what two things to the exocrine secretion? What secretes the enzymes?
Bicarbonate and water
Pancreatic acinar cells
Fill in the blanks from intercalated duct to hepatopancreatic ampulla of duodenum.
Intercalated duct –> intralobular collecting duct –> interlobular ducts –> main pancreatic duct –> hepatopancreatic ampulla of duodenum
What is the regulation of the exocrine pancreas secretion under?
Hormonal AND neural control
What two hormones are secretion of enteroendrocrine cells? What do they stimulate?
Secretin and CCK
Stimulate secretion of enzymes and proenzymes by the exocrine pancreas
Pancreas receives sympathetic and parasympathetic innervation. What do they do?
Sympathetic nerve fibers are involved in regulation of pancreatic blood flow
Parasympathetic fibers stimulate the activity of acinar and centroacinar cells
Endocrine pancreas is formed by islets of Langerhans which regulate what?
Blood glucose level
What has cells arranged into cords that follow fenestrated capillaries and appear as clusters of pale-staining cells surrounded by the darker serous acini? What is missing here?
Islets of Langerhans
No CT capsule
What secretes glucagon, found int he periphery of the islets of Langerhans, and has the action reciprocal to insulin?
A cells
What cells secrete insulin, are most abundant in the islet, and found in the center?
B cells
What secretes somatostatin?
D cells
What functions as an exocrine organ and endocrine gland?
The liver
-exocrine organ producing bile
What does bile contain?
- Conjugated and degraded waste products for disposal
- water
- bile salts (detergents that emulsify the fat)
- bilirubin (end product of hemoglobin degradation)
- electrolytes
What is a vital function of the liver?
Synthesis of most of the body’s circulating plasma proteins
The liver can take up lipids from the blood and either utilize them or release it back to the blood as what?
VLDL
What controls blood glucose levels?
Liver
What does the liver store?
Vitamin A
Vitamin ___ is transported from the small intestine to the liver by _____.
K
Chylomicra
Liver plays a major role in the storage, metabolism, and homeostasis of what?
Iron
What consists of organized plates of hepatocytes? Plates are one cell-thick and are separated by what? What do the plates form?
Parenchyma
Sinusoid also capillaries
Hepatic lobules
Liver is surrounded by a CT capsule called what? Where is it thicker?
Glisson’s capsule thicker at the Hilmes where blood vessels enter and exit the organ
What carries nutrient-rich, but low in oxygen blood from the spleen, pancreas, and alimentary canal? Where does oxygenated blood come from?
Portal vein
Hepatic artery from celiac trunk
Hepatic lobules drain into what before the IVC? Does this accompany the hepatic artery branches?
Hepatic lobule –> hepatic vein –> IVC
NO!
Portal vein and hepatic artery form conducting branches which travel to what? What do they constitute?
Interlobular spaces
Portal triad
The terminal branches of the portal vein and hepatic artery deliver blood to what?
Hepatic sinusoids
What are large, discontinuous capillaries with fenestrated endothelial cells? There are often gaps between individual endothelial cells.
Hepatic sinusoids
What do sinusoids separate?
Plates of hepatocytes
Blood flow from hepatic sinusoids to hepatic veins?
Hepatic sinusoids –> central vein (little to no CT) –> sublobular veins (more CT) –> collecting tributaries –> hepatic veins
The main type of cell in the liver is a ___ which is a ___ cell.
Hepatocytes, secretory
Average lifespan 3 months. High ability for regeneration if significant amount was lost due to intoxication or disease. A multifunctional cell.
Hepatocytes
Hepatocytes nucleus is large and spherical. Many cells are _____ and a majority are ____. Nucleus is ____ with one or two well-developed nucleoli.
Binucleated
Tetraploid
Euchromatic
What is abundant int he cytoplasm of hepatocytes and account for the eosinophils staining?
Mitochondria
What is the principal site for the synthesis of lipids? Other important function?
SER
Detoxification of noxious substances
What is abundant in the cytoplasm of hepatocytes and metabolize long-chain fatty acids for synthesis of bile acids?
Peroxisomes
What is concentrated near bile canaliculus and is a site for iron storage?
Lysosomes
This is part of the mononuclear phagocytic system and resides in the hepatic sinusoids. Important in phagocytosis get particulate matter.
Kupffer cells
Where are fat-storing cells found? Major function is storage of ___ and ____. Derived from ____ and in pathological conditions they proliferate and start synthesized collagen causing liver ____.
Space of Disse
Vitamin A and lipids
Fibroblasts
Fibrosis
What is the narrow space between hepatocytes and the basement membrane of the sinusoids?
Space of Disse
Portal canals bring ____ to the lobule and collect ____ from the lobule. What do portal canals contain?
Blood to
Bile from
Portal triad and loose CT
Portal triad 3 main components?
Interlobular branch of portal vein
Interlobular branch of hepatic artery
Interlobular bile duct- lined with simple cuboidal epithelium
The blood in hepatic sinusoids flows from the _____ of the lobule toward the _____.
The bile in the bile canaliculi forms from the ____ of the lobule toward the ____.
Blood: periphery to central vein
Bile: center to periphery
What is the site of exchange of materials between blood and liver cells?
Space of Disse
What cells are found in the space of Disse?
Fat-storing cells
What does the portal lobule emphasize? What is it centered on? Shape?
Exocrine function
Portal triad
Triangle
What is centered on terminal branches of portal vein/hepatic artery and on canals of Hering? Shape? Emphasizes what?
Liver acinus
Rhomboid
Different oxygen and nutrient content of blood present in the lobule
What zone is the first to receive oxygen, nutrients and toxins from blood? Last to die and first to regenerate if what is impaired? First to show changes and death during what?
Zone 1
Circulation is impaired
Bile stasis and intoxication
What zone dies first in reduced perfusion, but is last to respond to toxins and bile stasis?
Zone 3
What is the only lining of a bile canaliculus formed by?
Hepatocytes
Flow from bile canaliculi to common hepatic duct?
Bile canaliculi –> bile ductules –> interlobular bile ducts (portal triad) –> increase in size –> L and R hepatic ducts –> common hepatic duct
Lumen of gallbladder is lined with simple columnar epithelium specialized for what?
Absorption
Muscularis externa of gallbladder is formed by?
Bundles of smooth muscle and collagen
Part of gallbladder projecting into the peritoneum is covered by ____ while the rest is covered by ____.
Serosa
Adventitia
