What are the treatment options for acute cholecystitis?
- If an infective cause give antibiotics
What happens to the bile acids in the duodenum?
They are degraded by the flora to primary and secondary bile acids
Which enzyme reduces biliverdin, and what is the breakdown product?
Biliverdin reductase and produce bilirubin --> orange-red pigment
What is the function of Amylin?
- It slows gastric emptying and pancreatic secretions
- It inhibits glucagon production
- Produced by β-cells of the pancreas islets
What tumour marker is raised in pancreatic carcinoma?
How does obstructive jaundice and cholangitis present?
- RUQ pain
- Nausea and Vomiting
Jaundice; yellow skin and sclera, itchy skin, pale stools and dark urine
What level of serum amylase is used to suggest acute pancreatitis?
Anything over 3 times the normal limits suggest acute pancreatitis.
What happens to the secreted bile acids in the terminal ileum after they fulfil their function?
- 95% are reabsorbed in the terminal portion of the ilium
- Only 5% are lost each day
This equates to around 0.5g lost per day, which is replenished by the body
Once reabsorbed they are carried by albumin in the portal blood, back to the liver where they are re-synthesised and recycled.
What are the different types of gallstones, and what 1 is the most prevalent?
- Cholesterol - 80%
- Black pigment stones
- Brown pigment stones
What are the endocrine and exocrine functions of the pancreas?
- Endocrine - metabolic control via insulin and glucagon
- Exocrine - digestion via enzyme secretion and neutralisation of duodenal contents via HCO3 secretion.
How does acute pancreatitis present?
- Severe upper abdo pain, may radiate to back
- History of these lasting for few day/weeks
What the average lifespan of a RBC
What hormone is released in response to low pH in the duodenum?
What are the symptoms of pancreatic insufficiency?
- Maldigestion leading to malabsorption
- Diarrhoea and steatorrhoea
- Weight loss and malnutrition
- Deficiency of fat soluble vitamins - A, D, E, K
What factors in the duodenum favour the production of emulsion droplets?
- Churning action
- Alkaline pH
What causes the development of black pigment stones?
- Calcium bilrubinate
- Unknown cause, but they are associated with haemolytic disease.
What is the main phospholipid phospholipase A2 breaks down?
What is a bile salt?
It is a bile acid that is conjugated with either taurine or glycine to make it more ionised.
What are the functions of bile acids?
- Excretion route for cholesterol
- Emulsify lipids
- Form mixed micelles
What stimulates the secretion of CCK into the bloodstream?
Protein and lipids in the duodenum.
What are the 4 lipolytic enzymes secreted by the pancreas?
- Phospholipase A2
- Cholesterol esterase
What cell types are found in the islets of the pancreas?
- α - produce glucagon
- β - produce insulin and amylin
- δ - produce somatostatin
How much pancreatic secretion is released in the cephalic phase of digestion?
Up to a third of the maximal secretion volume.
Who are the people at risk of developing acute pancreatitis?
Middle age to elderly - gallstones
- Young men - alcohol
What are the treatment options for biliary colic?
- Mostly conservative as the stone is likely to pass, but is also likely to reoccur
What are the 2 essential fatty acids that must be taken in through the diet?
- Linoleic acid
- Linolenic acid
What happens to most the urobilinogen that is produced by the gut flora?
It is oxidised by intestinal bacteria to stercobilin, which gives the characteristic brown colour to poo
A small amount is reabsorbed and converted to urobilins by the kidneys and gives the urine its characteristic colour
What happens to bilirubin diglucuronide in the intestine?
It is hydrolysed and reduced to urobilinogen by gut flora
What are the predisposing factors for gallstones?
- Increased age
- Certain drugs
What are the functions of CCK?
- Gallbladder contraction
- Sphincter of Oddi relaxation
- Stimulates pancreatic acinar cells to secrete enzymes.
What is the prevalence of gallstones?
- It is about 10-20% in developed countries
- Around 80% of people are asymptomatic .
What enzyme is responsible for the initial degradation of haem, and the subsequent step of cleaving the porphyrin ring.
Microsomal haem oxygenase
What happens to bilirubin diglucuronide after it is produced?
It is actively transported into the bile canaliculi and bile
What system is responsible for the degradation of RBCs?
The reticuloendothelial system in the liver and spleen.
What is gallstone ileus?
- It is erosion of the gallbladder into the duodenum or large intestine and occludes the ileo-caecal junction
- It is caused by a large gallstone
What investigations can be performed for obstructive jaundice?
- Bloods; inc bilirubin, low serum albumin, and high prothrombin time should be seen
- Imaging; USS, CT, MRI, HIDA - dilation of biliary tree and masses.
What causes the formation of brown pigment stones?
Calcium/Fatty Acid stones --> layered
- Develop due to bile stasis or infection.
Where does secretin act?
It acts on receptors in the duct cells of the pancreas which secrete water and HCO3 into the pancreatic ducts and then duodenum to neutralise the pH.
How can pancreatic carcinoma present?
- Relentless severe abdo pain, which may radiate to the back
- Weight loss
- Painless jaundice
- Recent onset of diabetes
- Large liver is metastases
What causes the development of cholesterol gallstones?
- Cholesterol supersaturation
- Reduced bile salts
- Promoting factors such as mucins
What conditions can cause pancreatic insufficency?
- Chronic pancreatitis - usually caused by alcohol
- Duct obstruction as seen in tumours
- Pancreatic atrophy
What is the first breakdown product of haem, and what colour is it?
Bilverdin --> Green
What is the cause of biliary colic, and what is a complication of it?
- A gallstone blocking the cystic duct or common bile duct
- It can develop into a mucocoele of the GB; the bile acids are reabsorbed, but the GB remains distended with mucous.
What investigations can be performed for acute cholecystitis?
- Bloods - increased inflammatory markers should be present
- Imaging; USS, CT, MRI and HIDA
Which nerve contributes to the control of pancreatic exocrine secretions?
The vagus nerve
How does chronic pancreatitis present?
- Severe, persistent or intermittent upper abdo pain which may radiate to back
- Weight loss
How is bilirubin converted into bilirubin diglucuronide?
In the hepatocytes 2 molecules of glucuronic acid are added by the enzyme glucuronyltransferase
Why is the release of trypsin important?
It plays a pivitol role in the activation of many digestive pro-enzymes
What are the risk factors for chronic pancreatitis?
- Young-middle aged men who drink regularly
- Poor nutrition in 3rd world
What is acute cholecystitis, and what are its complications?
- It is obstruction of the gallbladder or cystic duct leading to inflammation of the gallbladder ± infection
- If infection is present can lead to empyema of the gallbladder
Perforation of the gallbladder is another complication which develops into peritonitis.
How does biliary colic present?
Pain in the right upper quadrant that is relentless
- The pain is also constant or crescendo like, and may radiate to the tip of the right shoulder
- The pain is made worse by a fatty meal
- The patient also has nausea and vomiting
What are the most common causes of acute pancreatitis?
- Gall stones
How does acute cholecystitis present?
RUQ pain, that is colicky in nature and may radiate to R shoulder
- Nausea and vomiting
Guarding and tenderness present
Positive Murphy's sign - With hand on abdo, patient inspires and stops due to pain of the gallbladder pressing into the hand
What substances inhibit the exocrine function of the pancreas?
- Pancreatic polypeptide
What is obstructive jaundice and what is its potentially fatal complication?
- It is obstruction of the hepatic duct or common bile duct by gallstones or a mass in the head of the pancreas leading to jaundice
- It can develop into ascending cholangitis, where an infection spreads up the static bile from the duodenum
What is meant by the term bile pigments?
It refers to bilirubin and its derivatives
How does colipase aid in the breakdown of triglycerides?
It binds to the triglyceride and serves as an anchor for lipase to attach to and cleave the FA from the glycerol backbone.
What investigations can be carried out for biliary colic?
- Imaging; CT, MRI, USS, HIDA scan
Which enzymes are measured in the blood if a patient has suspected acute pancreatitis?
Amylase - in UK
- Lipase - US, more sensitive than amylase.
What are the 2 most common bile acids?
- Cholic acid
- Chenodeoxycholic acid
What different cell types are found in the pancreas?
- Duct cells - 10%
- Acinar cells - 80%
- Islet cell - 10%
What are the treatment options for obstructive jaundice?