Liver and pancreas exocrine function Flashcards
1
Q
Functions of liver
A
T4 -> T3 Detoxification Production of cholesterol Stores glycogen Stimulates gluconeogenesis from fatty acids and glycerol Cytochrome P450
2
Q
Vit K dependent sites
A
2,7,9,10
3
Q
RBC breakdown
A
- RBC → free Hb
- Haem → biliverdin and iron
- Globulin → amino acids
- Biliverdin → bilirubin → conjugates bilirubin → bile → stercobilin or urobilin
- Reabsorption of bile acid through enterohepatic circulation
- Too much bilirubin → jaundice
- Bilirubin is itchy
4
Q
Bile acid secretion
A
- Enters duodenum via sphincter of oddi
- Traction of gall bladder pushed bile down and sphincter of oddi relaxes
- Fat-containing food releases cholecystokinin causes gallbladder contraction and relaxation of sphincter
- Secretin causes intra-hepatic secretion
5
Q
Vitamins in liver
A
- Vit B12, A and D stored in large amounts in liver
- Vit K and folate in small amounts
6
Q
Hepcidin
A
- Produced by liver when blood contains iron
- Stops reabsorption of iron via ferroportin 1
- Too much iron = haemochromatosis → cirrhosis of liver and failure
7
Q
Causes of liver disease
A
- Alcohol related liver disease - alcohol is short chain
- Hepatitis B and C
- NAFLD, NASH
8
Q
Non-alcoholic fatty liver disease
A
- Changes from simple steatosis to steatohepatitis and fibrosis
- Associated with metabolic syndrome compartments
- Exacerbates insulin resistance and increases cardiovascular risk
- Related to lipids and lipotoxicity
9
Q
Acites
A
Build up of fluid
- Fluid build up in peritoneal cavity
- Decreased albumin
- Increased hydrostatic pressure
- Aldosterone is not metabolised = splanchnic vasodilation
- Drained by ascitic tap
- No immune response from cirrhotic liver → peritonitis
10
Q
Peritonitis
A
Bacterial infection in ascitic fluid
11
Q
Hepatorenal syndrome
A
Leads to liver and kidney failure
12
Q
Hepatopulmonary syndrome
A
Leads to oedema
13
Q
How is bilirubin produced
A
RBC metabolism
14
Q
Symptoms of liver failure
A
- Ascites
- Bleeding
- Bruising
- Jaundiced
- Itchy
- Confusion
15
Q
Signs of chronic liver disease
A
- Hands - erythema, clubbing
- Eyes/skin - jaundice, loss of hair, bruising
- Chest - gynaecomastia, spider naevi
- Abdomen - hepatomegaly, splenomegaly, caput medusae
- Legs - oedema
- Lipid deposits = xanthelasma
16
Q
Asterixis
A
- Liver flap
- Seen in hyper-uraemia, t2 respiratory failure, electrolyte disturbance, phenytoin and barbituates
17
Q
Blood test for liver disease
A
- LFTS - ALT, bilirubin, ALP, albumin, AST, gamma GT
- Coagulation - PT /INR
- FBC - Hb and platelets
18
Q
Imaging for liver disease
A
- Texture of liver
- Focal lesoins
- Gall bladder
- Portal vein - thrombus, flow rate, hypertension
- Splenomegaly
- Stiffness of liver
19
Q
Fibrocan
A
F4 = cirrhosis, F0/1 is no/mild fibrosis
20
Q
Management of liver disease
A
- Treat decompensation
- If ascitic, sule out peritonitis
- Diuretics
- Ascitic drain
- Check INR and give INR
- If bleed suspected, duodendoscopy and beta blocker
- Lactulose/enemas
21
Q
Long-term management liver disease
A
- Treat underlying cause
- Alcohol cessation
- Lactulose, rifaximin
- Nutrition
- Diuretics
- B blockers
22
Q
Liver regeneration
A
- Associated with signalling cascades - growth factors, cytokines, matrix remodelling
- Liver restores any mass lost and adjusts its size to the organism
23
Q
TIPS
A
- Trans-jugular intrahepatic portosystemic shunt
- Development of oesophageal varices - can do a shunt to bypass liver and leads to hepatic encephalopathy (toxins to brain)
- Shunt between hepatic vein and portal vein
24
Q
Pancreas
A
- Digestive enzymes enter duodenum via sphincter of oddi
- Endocrine: insulin, somatostatin, glucagon, pancreatic polypeptide, ghrelin
- Exocrine: digestive enzymes, bicarbonate
- Digestive enzymes from acinar cells
- HCO3- from ductal cells
25
Producing bicarbonate
- SLC26A6 absorbs negative ions and exchanging for HCO3-
- Neutralises stomach contents
- Controlled by ACh (stimulates bicarbonate secretion)and vagus nerve
- High level of water needed - transfers through passively between cells
- Secretin drives expulsion of bicarbonate into duct
26
Pancreatic acinar cells
- Secrete digestive enzymes to small intestine via pancreatic duct
- Zymogens are enzymes secreted in vesicles
- Enzymes activated in small intestine aid breakdown of carbohydrates, fats, proteins
27
Exocrine function of pancreas
- Pancreatic enzymes secreted from acinar cells in response to secretin and CCK
- Necessary for digestion of fat, protein and carbohydrate
- Secreted from ductular cells to produce optimum pH for enzymes
28
Carbohydrate digestion
- Starch broken down
- Enters duodenum
- Starch acted on by amylase
- Absorbed in epithelium cells
29
Protein digestion
- Broken into amino acids
- Pepsinogen activated by acidic environment → smaller peptides
- Peptides broken down by proteolytic enzymes
- Trypsinogen, chymotrypsinogen and procarboxypeptidase
- Intrinsic factor secreted from stomach binds to B12
- No intrinsic factor = no B12
30
Lipid digestion
- Lipase from pancreas acts in conjunction of bile
- Lipase → small particles → chylomicrons from micelles → thoracic duct or portal vein
- Vagal nerve via ACh stimulates release of enzymes into acini
- Secretin and cholecystokinin released due to acidic environment
- Secretin causes pancreatic fluid to be made
- Cholecystokinin causes enzyme secretion
31
Sx pancreatic insufficiency
- Pancreas is main source of lipase → insufficiency = unable to digest lipids
- Loose, pale, greasy stools that float
- Weight loss
- Fatigue
- Abdominal distension
- Lack of vitamins
- Amylase/proteolytic enzymes found elsewhere
32
Treatment pancreatic insufficiency
Creon
