Accessory Organs Of Digestion Flashcards
Where is the liver found?
In the upper right quadrant of the abdomen directly beneath the diaphragm
What are the functions of the liver?
Glucose storage, protein - liproprotein and cholesterol synthesis, digestion, storage of fat soluble vitamins, toxin and drug metabolism and excretion
What are the 4 lobes of the liver?
Right, left, caudate and quadrate
What is the gallbladder?
It is a fluid filled sac and stores and concentrates bile
What is the gallbladder made up of?
Fungus, body and neck. The neck leads to the cystic duct which transports bile to and from the gallbladder
What colour can the gallbladder be?
Green due to the bile acids
What is the hepatobiliary system?
Looks at he production and flow of bile
What is bile produced by?
By hepatocytes in the liver
What do enzymes in the liver do?
Breakdown alcohol and other drugs producing toxic waste products and these may be excreted by the kidneys in the bile
What is the function of bile when released in the stomach?
It has a bicarbonate content and it produces an alkaline pH that serves to decrease the acidity of gastric contents released from the stomach, preventing damage to the intestines
What does a decreased pH facilitate?
The emulsion of fats from the stomach by salts contained in the bile.
What does the emulsification of fats by bile salts increase?
It increase the surface area of insoluble nutrients and increases the rate of their digestion
What are hepatocytes of the liver arranged to be?
They are epithelial cells arranged to form a 3D lattice
What runs between each layer of hepatocytes in the liver?
Sinusoids which allow close contact between the hepatocytes and portal blood supply
How are the products of hepatocytes removed?
By canaliculi - which are channels between the cells the drained into the bile ducts
Where does bile drain to?
From the liver via the right and left haptic ducts which join to form the common hepatic duct
What is the common hepatic ducts joined by?
Cystic duct that drains bile from the gallbladder which forms the common bile duct
Where does hole from the common hepatic duct travel to?
Travels to the cystic duct to be stored in the gallbladder or carry on descending duodenum via the common bile duct
What does the presence of food in the duodenum stimulate?
Stimulates the gallbladder to contract
Where does the main pancreatic duct join the common bile duct?
At the hepatopancreatic ampulla which opens into the duodenum
What happens if you have an occlusion (e.g. a gallstone)?
Both bile and pancreatic enzyme secretions will be blocked
What is the pancreas?
It is an elongated gland that has endocrine and exocrine functions
Where does the pancreas lie?
It lies horizontal across the posterior abdominal wall and it sits postoperative to the stomach and is split into 5 regions
What are the 5 regions of the pancreas?
Uncinate process, head, neck, body and tail
What do exocrine tissues of the pancreas release?
Pancreatic juice, a major digestive secretion enzymes
What are the two components of pancreatic juice?
Alkaline secretion and enzyme rich secretion
Describe the alkaline secretion
It has a high bicarbonate and low enzyme content which helps neutralise the acidity of gastric contents
Describe the enzyme rich secretion
Contains the major enzymes involved in digestion. It is secreted as pre-enzymes that are activated in the gut so they don’t digest the pancreas
What control is the pancreas under?
Partially under autonomic control - sympathetic stimulation decreases secretions and parasympathetic stimulation increases secretions
What are the exocrine glands?
Compound acinar, the enzymes are secreted in the acinus and modified in the ducts
How is the pancreatic juice transported to the duodenum?
Via the main pancreatic duct which join the common bile duct to form the hepatopancreatic ampulla
What is the entrance of pancreatic juices to the descending duodenum controlled by?
Hepatopancreatic sphincter
