Pancreas and Liver Flashcards
What is the pancreas ?
A large gland that has both endocrine and exocrine functions.
Parts of the pancreas
Tail
Body
Neck
Uncinate process
Head
What does the pancreatic duct combine with ?
Common bile duct
3 Components of the Sphincter of Oddi
What are the primary functions of the pancreas ?
Neutralise acid content from the stomach
Deliver enzymes for macronutrient digestion in duodenum.
Where is pancreatic blood supply mainly from ?
Splenic artery from the Coeliac trunk
Pancreatico-duodenal arteries from the Superior mesenteric artery
What does the exocrine pancreas do ?
Secretes enzymes and bicarbonate.
The enzymes are secreted in their inactive forms to be activated in the small intestine.
3 phases of exocrine pancreatic regulation
Cephalic
Gastric
Intestinal
What stimulates duct cell secretion ?
Secretin
ACh
What is HCO3 secreted for ?
To aid in the neutralisation of stomach acid
Provides an optimal pH environment for digestive enzymes to function in the duodenum
What is the function of acinar cells ?
Secrete (pro)enzymes and fluid
The pancreatic acinar cell is the functional unit of the exocrine pancreas.
Synthesises, stores, and secretes digestive enzymes.
What is the function of duct cells ?
Secrete bicarbonate
What is cystic fibrosis ?
Autosomal recessive disease
What is the result of cystic fibrosis ?
Progressive pancreatic and pulmonary insufficiency
How does the result of cystic fibrosis occur ?
Mutations in the CFTR gene which codes for cAMP-regulated chloride channel.
Leads to decrease in HCO3- secretion, blockage of ducts and eventual destruction of pancreas.
Lack of digestive enzymes leads to maldigestion of nutrients.
What is acute pancreatitis ?
Inflammatory condition that may cause local damage to pancreas.
Causes of acute pancreatitis
Alcohol
Gallstones
(pathogenesis thought to occur in acinar cells)
What does bile consist of ?
Bile acids
Electrolytes
Cholesterol
Phospholipids
Bilirubin.
Where is bile concentrated more : the liver or the gallbladder ?
Gallbladder
What does CCK cause ?
It causes the Gallbladder to contract and the Sphincter of Oddi to relax, therefore moving bile into the small intestine.
Lobes of the liver
4 lobes :
Right lobe, Left lobe, Quadrate lobe, Caudate lobe
What separates the right and left lobes of the liver ?
Falciform ligament
What is near the quadrate lobe ?
The gallbladder
What is near the caudate lobe ?
The inferior vena cava
What is bare area in the liver ?
Diaphragmatic surface of the liver with no peritoneal covering. - on the right lobe
What is the largest organ in the body ?
The liver
Blood supply to the liver
Hepatic artery (25%)
Portal vein (75%)
What is the direction of bile flow in the liver ?
Opposite to blood flow
Function of the sphincter of Oddi
Regulates bile release into the small intestine
Function of the liver
Participates in carbohydrate, lipid and protein metabolism and storage.
Cleans toxins (harmful substances) out of the blood.
Gets rid of old red blood cells.
Produces substances to help blood clot.
Regulates the amount of blood in the body.
Stores glycogen (an energy source) and vitamins to be used by the body later.
Makes bile
How does the liver detoxify metabolic waste ?
Removal of ammonia and ethanol.
Drug transformations
What does the liver produce to aid in blood clotting ?
Fibrinogen
Prothrombin
What is the function of Kupffer cells ?
Kupffer cells are resident liver macrophages and play a critical role in maintaining liver functions.
Under physiological conditions, they are the first innate immune cells and protect the liver from bacterial infections.
What does the liver produce large amounts of ?
Lymph and is involved in many immune related functions.
What are the lobes of the liver made up of ?
Each lobe is made up of thousands of hexagonally-shaped lobules.
Describe the structure of a liver lobule
Hexagon shaped lobule
Portal triads at each of the 6 corners
Each lobule is made up of hepatocytes
What are triads in the liver ?
Branches of :
- Hepatic artery
- Hepatic portal vein
- Bile duct
Function of the hepatic bile duct
The hepatic duct transports bile, produced by the liver cells, to the gallbladder and duodenum.
What are hepatocytes ?
Liver cells
How does bile drain ?
Via canaliculi that lie between hepatocytes and eventually form bile ducts.
Function of the portal vein
Carries nutrient-rich blood from the intestines to the liver.
Function of the hepatic artery
Delivers oxygen-rich blood from the heart to the liver.
What are sinusoids ?
Found between rows of hepatocytes.
These small blood vessels diffuse oxygen and nutrients through their capillary walls into the liver cells.
In what direction does bile flow ?
Opposite direction to blood flow
What is the function of the peribiliary plexus ?
Empties into the sinusoids by branches of the portal vein.
Glucogenesis
Production of new glucose
Glycogenolysis
Breakdown of glycogen
Lipogenesis
Storage of fatty acids as triglycerides
Lipolysis
Production of fatty acids
Where is the gallbladder located ?
Below the right lobe of the liver lies the gallbladder — a hollow, pear-shaped, saclike organ.
What is the function of the gallbladder ?
The gallbladder stores bile, a greenish brown fluid produced by the liver to help the body break down and use fats.
When a person eats, the gallbladder empties bile into the intestines to help digest food.
What controls the flow of bile into the duodenum ?
Sphincter of Oddi
Which is more concentrated hepatic bile or gallbladder bile ?
Gallbladder bile
What is Cholestasis ?
Suppression of bile secretion
Results of cholestasis
Regurgitation of bile components leads to jaundice and pruritis
Damage to hepatocytes
Causes of cholestasis
Mechanical obstruction
What are Gallstones ?
Gallstones are small stones, usually made of cholesterol, that form in the gallbladder.
How do gallstones form ?
Disturbance of bile secretion and cholesterol elimination leading to bile supersaturated with cholesterol.
Function of CCK
Causes gallbladder contractions to move bile into the small intestine.
Causes relaxation of the Sphinchter of Oddi.
