case 3 anatomy Flashcards
histology of salivary glands
The secretory units of the salivary glands consist of a branched tubulo-acinar structure. The acinar cells produce either serous, mucous or a mixed saliva. In some cases the serous cells form caps around the mucous secreting acini. These caps are referred to as serous demilunes. Cells which produce serous saliva stain much darker with H&E stain compared to mucous secreting cells.
The acini cells secrete saliva into small intercalated ducts which, in turn, drain into larger striated ducts and then into even larger excretory ducts.
histology of the pancreas
The pancreas is a mixed endocrine and endocrine gland. It is surrounded by a thin connective tissue capsule. Septa extend into the gland from the capsule separating the pancreatic lobules.
The exocrine component of the gland is similar to the parotid gland. It consists of closely packed secretory acini which drain into a duct system. The smallest intercalated ducts drain into intralobular ducts which, in turn, drain into interlobular ducts. The interlobular ducts are located in the septa of the gland. The interlobular ducts drain into either the main pancreatic duct or the accessory pancreatic duct.
The endocrine component of the gland is comprised of clusters of cells known as the pancreatic islets (islets of Langerhans). These are scattered throughout the gland but are most numerous in the tail. The islets vary in size and are composed of a number of different cell types, each of which is responsible for secreting one type of hormone.
histology of the liver
The liver is covered by a thin capsule, termed Glisson’s capsule. The capsule is thicker at the porta hepatis and it surrounds the vessels and ducts as they extend into the gland. The hepatocytes and the sinusoids are surrounded by a fine, supportive reticular network. the liver lobule is also important in the histological sections.
porta hepatis
deep fissure in the inferior surface of the liver through which all the neurovascular structures (except hepatic veins) and hepatic ducts enter or leave the liver. It contains: right and left hepatic ducts. right and left branches of hepatic artery. portal vein.
gall bladder
The wall of the gall bladder is similar to that of the gastrointestinal tract but it lacks the submucosal layer. The mucosa consists of a layer of simple columnar epithelium and a supporting lamina propria. There is no distinct submucosa and only one muscularis is evident. This is a thin layer which is composed of muscle fibres orientated in many directions. The outer layer of the gall bladder is serosa in parts and an adventia in others
biliary tree
liver-right and left hepatic ducts-common hepatic duct-gallbladder-cystic duct-bile duct-hepatopancreatic ampulla-duodenum. If fat is present in the duodenum the sphincter of Oddi (hepatopancreatic sphincter) will be open and bile will be able to enter. In the absence of fat, the sphincter will be closed and the bile will track back up the bile duct, into the cystic duct and into the gall bladder.
What is the name given to the hormone that is released by the enteroendocrine cells when fat is present in the duodenum?
cholecystokinin (CCK)
what splanchnic nerve provides symp innervation to the gall bladder
greater splanchnic as in the forgut so T5-9
which ganglion do postganglionic symp fibres for the gall bladder arise
coeliac
which nerve transmits parasymp to the gall bladder
vagus
gall bladder blood supply
he arterial supply to the gall bladder is provided through the cystic artery. The custic artery arises from the right hepatic artery. The cystic artery is usually located in the triangle (cystohepatic) between the inferior border of the liver, cystic duct and common hepatic duct.
Venous drainage - the fundus and body is drained directly through the visceral surface of liver into hepatic sinusoids. the neck and cystic duct are drained by cystic veins which drain into the liver directly or via portal vein.
lymphatic drainage of the gall bladder
cystic nodes-hepatic nodes-coeliac nodes-intestinal trunk-cisterna chyli-thoracic duct-left subclavian vein
fundus of gall bladder
Rounded portion of the gall bladder that projects from the lower border of the liver. Located at the tip of the 9th costal cartilage in the midclavicular line.
body of the gall bladder
Main part of gall bladder that is located posterior to the liver, superior part of duodenum and the transverse colon.
neck of the gall bladder
The part of the gall bladder which is continuous with the cystic duct, it lies superior to the duodenum.