Liver and Pancreas Physiology and Disease Flashcards
Which areas of the abdominal does the liver reside in?
Right hypochondrium
Epigastric
What do we call the 2 liver surfaces?
Diaphragmatic
Visceral
What is contained within the falciform ligament?
Remnant of umbilical vein
What is the role of the coronary and triangular ligaments of the liver?
Attach superior liver to the diaphragm
Which ligaments are contained in the lesser omentum?
Hepatoduodenal
Hepatogastric
Name the hepatic recesses and state where they are
Subphrenic spaces (left and right) - between diaphragm and liver
Subhepatic space - between liver inferior surface and transverse colon
Morison’s pouch - between liver and the right kidney
What is the deepest part of the peritoneal cavity when supine?
Morison’s pouch
What do we call the fibrous layer covering the liver?
Glisson’s capsule
What divides the liver into right and left lobes?
Falciform ligament
Where are the accessory lobes of the liver?
Visceral surface
Caudate - between the IVC and a fossa produced by ligamentum venosum
Quadrate - between gall bladder and fossa produced by ligamentum teres
What lies between the caudate and quadrate lobes?
Deep fissure - porta hepatis
What provides the dual blood supply to the liver?
Hepatic artery proper (from coeliac trunk)
Hepatic portal vein (from small intestine)
What is the dominant blood supply to the liver parenchyma?
Hepatic portal vein
How is the parenchyma of the liver innervated?
Hepatic plexus:
SNS - coeliac plexus
PNS - vagus nerve
What innervates the Glisson’s capsule?
Branches of the liver intercostal nerves
What kind of pain occurs with distension of the liver capsule?
Sharp
Well localised
Does the duodenum add or remove water to the gut lumen?
Adds (from ECF)
For dilution because chyme so hypertonic
What is the osmotic status of chyme when it leaves the duodenum?
Isotonic
What percentage of the pancreas is exocrine?
90%
Which basic parts of the pancreas produce the different exocrine parts?
Acinus - produces enzymes
Centroacinar - aqueous component
Duct - modifies secretion
What happens to pancreatic secretions if the flow is faster?
More HCO3- ions
More alkaline
Describe the neuronal control of the pancreas
SNS - inhibits secretions
PNS - vagus stimulates secretions
What stimulates the acinus to produce enzymes?
Vagus nerve
CCK
What stimulates the release of CCK in the duodenum?
Detection of hypertonicity, small peptides and fats in the duodenum
What enzymes are released from the pancreas?
Amylases and lipase
Proteases - trypsin, chymotrypsin, elastase, carboxypeptidases
(Proteases as zymogens)
What are zymogen granules?
Membrane bound
Contain inactive precursor of an enzyme
Pancreatic enzymes in the blood indicate …
Pancreatic damage
Pancreatitis
How high can the rate of mortality in pancreatitis be?
50%
What is the role of pancreatic duct cells?
Produce aqueous component - isotonic solution
Secrete HCO3- stimulated by secretin
HCO3- pumped into lumen therefore H+ moves into blood
(Transient lowering of pH of blood leaving the pancreas)
What are the roles of the liver?
Energy metabolism - glycogen storage
Detoxification
Plasma protein production
Bile production
How many hepatic veins attach the liver to the IVC?
3
How much bile is secreted per day?
250ml - 1 litre
Describe hepatocytes
Chief functional cell of liver
Very active at producing proteins/lipids for export
Contain lots of glycogen
What is the structural unit of the liver and describe?
Lobule Contains many hepatocytes in radiating branches Central vein Hexagonal Portal triads at each corner
What is the functional unit of the liver and describe?
Acinus
Diamond shaped - from one central vein to another in an adjacent lobule (long axis)
One portal triad to another - short axis
3 zones
Which zones of the acinus of the liver are most at risk?
Zone 1 - receives highest blood supply so most at risk of toxic damage
Zone 3 - receives lowest blood supply so most at risk of hypoxic damage
Which veins all drain together to make the hepatic portal vein?
Splenic vein Superior mesenteric vein Inferior mesenteric vein Gastric veins Cystic vein
What are the 2 component types of bile?
Bile acid dependent - bile acids and pigments
Bile acid independent - alkaline solution
What are the 2 primary bile acids?
Cholic acid
Chenodeoxycholic acid
What are bile salts?
Bile acids that are conjugated with amino acids
Glycine and taurine
Describe the structure and function of bile salts
Generally soluble at duodenal pH
Amphipathic molecules
Crucial for emulsification of dietary lipids
Form micelles with products of lipid breakdown
Moves fat into enterocytes and bile salts remain in gut
Reabsorbed at terminal ileum then go back to liver to be recycled
What are the products of lipid digestion in the gut?
Cholesterol
Monoglycerides
Free fatty acids
Inside cells, fat is re-esterified back to …
Triglycerides
Phospholipids
Cholesterol
What are chylomicrons?
Reformed lipids packaged with apoproteins
How do chylomicrons travel?
Exocytosis through basolateral membrane
Enter lymph capillaries - lacteals
Travel through lymphatic system
Re-enter vascular system at the thoracic duct
What is the function of the gall bladder?
To store and concentrate bile
Name the different types of gallstones we can get
Pigment stones - black
Cholesterol stones - yellow
Mixed stones - black and yellow
What is the effect of CCK towards bile?
Stimulates gall bladder contraction
Relaxes sphincter of Oddi
What is steatorrhoea?
Fat in the faeces
Pale, floating, foul smelling stool
If bile acids or pancreatic lipase are not secreted in adequate amounts
Give some common symptoms/signs of liver disease
Abnormal blood tests (LFTs) Abdominal pain Nausea/vomiting Jaundice Skin irritation Hepatomegaly
Give some signs of very severe liver disease
Small, irregular liver
Bleeding/poor clotting
Oedema
Encephalopathy
How do you get abdominal pain in liver diseases?
Inflamed liver/swelling
Surrounded by visceral peritoneum
Poorly localised visceral pain
Why do you become nauseous in liver failure?
High number of toxins in the blood
Liver cannot detoxify as well
Why can the skin become irritated in liver disease?
Bile salts deposited in the skin - itchy
Why do you get hepatomegaly in liver disease?
Inflammation and swelling
Increased fat deposition
How does ascites occur in liver failure?
Decreased albumin production
Decreased oncotic pressure of plasma
Fluid moves out of plasma
Also if portal hypertension - increased hydrostatic pressure in the portal system - fluid moves out
How does encephalopathy occur in liver disease?
Break down of the urea cycle Increase in ammonia Crosses in BBB Toxic to the brain Can lead to coma
Describe the life cycle of bilirubin
120 days in a RBC Bilirubin is the breakdown product of Hb Joined with albumin to carry to liver Conjugation Joined with bile salts and excess cholesterol Drains into biliary tree Secreted into duodenum Bilirubin converted to urobilinogen which gives colour to faeces Some bilirubin recycled to liver
Describe pre-hepatic jaundice
Excess bilirubin load to the liver
Excessive RBC breakdown eg. Haemolytic anaemia
Liver cannot conjugate fast enough
Unconjugated bilirubin remains in blood
Describe hepatic jaundice
Decreased rate of bilirubin conjugation
Injury/damage to liver or defects in conjugation
Some bilirubin remains insoluble
Describe post-hepatic jaundice
Obstruction to bile drainage into duodenum
Conjugated but cannot leav ebiliary tree
Refluxes into circulation
No bilirubin in stool - pale, fatty, smelly steatorrhoea
What are the tests for the true liver function?
Albumin
Clotting factors
Briefly describe hepatitis
Hepatocytes inflammation and breakdown Many causes: Viral Hep Autoimmune Drugs eg. Alcohol, paracetamol Hereditary disorders
How does chronic liver disease lead to cirrhosis?
Inflammation of the liver Ongoing liver cell damage/necrosis Nodular regeneration and fibrosis Architectural change to liver structure Increased resistance to blood flow
Describe the symptoms of stones in the biliary tree
Nausea/vomiting
Abdominal pain
Jaundice
(Fever and right upper quadrant pain = cholecystitis)
How do we tend to identify gall stones?
Ultrasound scan
What are the most common causes of pancreatitis?
Gallstones
Alcohol
What are the symptoms of pancreatitis?
Abdominal pain
Vomiting
Hypotension
What is the treatment for pancreatitis?
Supportive
Analgesics
Lots of IV fluids
What type of cancer is the majority of pancreatic cancers?
Ductal adenocarcinoma
What are the symptoms of pancreatic cancer as it progresses?
Obstructive jaundice Pain (referred to back) Weight loss Vomiting Malabsorption Diabetes
