| Question |
Answer |
| The thin connective tissue that covers the liver is known as what? |
Glisson's capsule |
| Exocrine function of the liver is what? |
Bile production |
| Function of bile? |
Aids in absorption of lipids from the intestine and the disposal of conjugated and degraded waste products. |
| Endocrine-like functions of the liver? |
Modifies structure and function of many hormones. (Vit. D, thyroxine, GH, insulin and glucagon) |
| What are the 2 suppliers of blood to the liver? |
Venous (portal) blood supply (75%) via the hepatic portal and arterial supply (25%) via the hepatic artery. |
| What did the blood of the venous portal vein initially supply? |
intestines, pancreas, and spleen |
| what does portal blood contain? |
nutrients and toxic materials absorbed in the intestines, blood cells and breakdown products of blood cells from the spleen, endocrine secretions from the pancreas and enteroendocrine cells of the GI tract |
| Hepatocytes are never fully exposed to _____ blood. |
oxygenated |
| What are liver parenchyma |
organized plates of hepatocytes |
| What are the 4 components of the liver structure? |
parenchyma, connective tissue stroma, sinusoidal capillaries (hepatic sinusoids), perisinusoidal (spaces of Disse) spaces |
| Where are perisinusoidal spaces located? |
between the sinusoidal endothelium and the hepatocytes |
| 3 ways to describe the structure of the liver as a functional unit |
classic lobule, portal lobule, liver acinus |
| What does a classic liver lobule consist of? |
hexagonal mass, stacks of anastomosing plates of hepatocytes separated by sinusoidal capillaries, centered on terminal hepatic venule, corners of lobule are the portal areas (portal canals) that contain the portal triads |
| What is the function of a portal lobule? |
bile production and secretion |
| What does a portal lobule consist of? |
triangular lobule: portal area in center that contains bile duct, terminal hepatic venule (central vein) at each corner |
| What does a liver acinus consist of? |
provides best correlation between blood perfusion, metabolic activity, and liver pathology... eliptical shape, short axis extends between 2 portal areas, long axis extends between 2 terminal hepatic venules |
| describe liver acinus zone 1 cells. |
first to receive oxygen, nutrients, and toxins from the blood, first to show effects of bile duct obstruction |
| describe zone 3 liver acinus cells. |
first to show effects of reduced perfusion, last to respond to toxins and bile stasis |
| describe type 2 liver acinus cells. |
intermediate between zone 1 and 3 |
| What is the common name for Stellate sinusoidal macrophages? |
Kupffer cells |
| What is the perisinusoidal space known as? |
space of Disse |
| The site of exchange of materials between the blood and liver cells is what? |
Perisinusoidal space (space of Disse) |
| In the fetal liver, islands of blood forming cells are located where? |
Perisinusoidal space (space of Disse) |
| Hepatic stellate cells are found where? |
Perisinusoidal space (space of Disse) |
| Primary site of storage for hepatic Vit. A is in the cytoplasmic droplets of what cells? |
Hepatic stellate cells |
| Plasma that remains in the Perisinusoidal space (space of Disse) drains in to what other space? |
space of Mall |
| Near the portal canals bile canaliculi join to form the what? |
Intrhepatic ductules (canals of Hering) |
| Canals of Hering are partially lined by what 2 cell types? |
Hepatocytes and Cholangiocytes |
| What is the pathway of bile secretion? |
Hepatocytes secrete bile into bile canaliculi, bile flows from the central vein towards the portal canal and into intrahepatic ductules. Intrahepatic ductules drain into interlobular bile ducts then to extrahepatic bile ducts and then on to the gall bladd |
| The gallbladder has what diagnostic features? |
simple columnar epithelium and the mucosa has abundant folds in which the epithelium is rich in mitochondria. |
| Contraction of smooth muscle of the gallbladder is induced by what? |
Cholecystokinin |
| What induces CCK to be released from enteroendocrine cells? |
Presence of dietary fats in the small intestines. |
| The exocrine portion of the pancreas is located where? |
throughout the pancreas |
| The endocrine portion of the pancreas is located where? |
Islets of Langerhans |
| Acini are composed of what? |
Serous cells surrounding a lumen. |
| Acinar store and release what? |
Proenzymes |
| Enterokinase does what? |
Cleaves trypsinogen into trypsin. |
| Pancreatic secretion is controlled by what 2 hormones? |
Secretin and cholecystokinin (produced by enteroendercrine cells of the intestinal mucosa) (duodenum and jejunum) |
| What is a strong stimulus for secretin? |
Gastric acid (pH <4.5) |
| Secretin has what action? |
causes duct cells to secrete large volume of fluid that are rich in bicarbonate but has little enzyme effect (neutralizes the acid which allows for optimal pH for pancreatic enzymes) |
| Cholecystokinin is released after what initiates it? |
Long-chain fatty acids, gastric acid and certain amino acids. |
| Islets of Langerhans consists of what? |
Cords of polygonal cells invested with a network of fenestrated capillaries. |
| Mallory-Azan technique can identify what cell types? |
Major cell types (A, B and D) |
| Grimelius silver stain can identify what? |
A cells |
| Delta cells secrete what? |
somatostatin |
| Minor cells are what? |
PP cells (F cells), D-1 cells, EC cells |
| PP cells secrete what? |
Pancreatic polypeptide |
| D-1 cells secrete what? |
Vasoactive intestinal polypeptide (VIP) |
| EC cells secrete what? |
Secretin, motilin and substance P |
| What action does somatostatin produce? |
inhibits insulin and glucogon secretion |
HHS Shrek
