Lecture 14 Flashcards
What are the specific signs of hepatic disease
Hepatomegaly Microhepatica Icterus Ascites Hepatoencephalopathy
What are the non-specific signs of hepatic disease
Depression Weightloss Anorexia Vomiting Abdominal PU/PD
What can liver failure affect
Nervous, renal and cutaneous systems
How is liver disease detectable
A variety of suggestive clinical signs Blood biochemistry
What are the consequences of liver failure
Hyoerbilirubinaemia Cutaneous lesions Vascular/haemodynamic alterations: portal hypertension Hypoalbuminaemia Bleeding tendency/coagulopathy Hepatic encephalopathy Impaired hepatic immune function
What is bilirubin
Pigmented waste product of RBC breakdown
What are bile acids
Made from cholesterol, responsible for emulsification and absorption of fat Decreased in intestine
What is phylloerythrin
Breakdown product of chlorophyll Increase in serum/tissue
What is hyperbilirubinaemia
Hepatic injury can cause increased concentration of bilirubin in blood causes jaundice
What are the 3 main reasons of hyperbilirubinaemia
Excessive haemolysis - over production of bilirubin from haemoglobin breakdown Severe liver damage - reduced uptake conjunction and secretion of bilirubin by hepatocytes Cholestasis - intrahepatic or extra hepatic cholestasis
What is bile calculi
Solid precipitate from supersaturated bile constituents Only a problem if cause obstruction
What is photosensitisation
Skin injury/necrosis due to activation of photodynamic pigments by UV high from sun
What is primary photosensitisation
Ingest specific toxic plants containing photodynamic pigments
What is secondary photosensitisation
Liver damage or cholestasis especially if on green feed
What is a plant that causes primary photosensitisation
St John’s Wort (Hypericum perforatum)
What happens with secondary photosensitisation
Phylloerythrin is produced from chlorophyll in ingested green plants by bacteria in intestines
What is hepatocutaneous syndrome
Syndrome of chronic liver injury and skin disease Epidermis is affected Crusting, erosions. ulceration
What is portal hypertension
Elevation in BP in normally low pressure portal vein
What is the cause of portal hypertension
Increased resistance to portal blood flow
What are the extensive diffuse fibrosis of the liver causes
Increased resistance to blood flow within the liver - Portal hypertension - Acquired portosystemic shunts Portal hypertension also causes - Ascites
What is hypoalbuminaemia
- Reduced albumin synthesis of the liver - Loss of albumin in GIT due to portal hypertension - Can cause generalised oedema - Can cause ascites
What causes bleeding tendency
- Impaired synthesis of coagulation factors - Biliary obstruction causes impaired fat absorption - Altered platelet function - Reduced clearance of FDPs, activated clotting factors and plasminogen - Dysfibrinogenaemia
What is coagulopathy secondary to
Extensive acute hepatic necrosis
Hepatic Encephalopathy: disorders of the CNS
Abnormal neuromuscular and CNS neurotransmission Due to increased plasma ammonia (HN3) and/or other toxic metabolites Exacerbated by hypoglycaemia that can also occur
Hepatic Encephalopathy: what causes brain - spongy vacuolation of white matter
From increased plasma NH3
What is the consequence of hepatic immune function
Shunting of blood due to fibrosis, cirrhosis - Blood bypasses liver parenchyma - Reduced blood filtration by Kupffer cells - Reduced removal of infectious agents, LPS ect - Frequently develop endotoxaemia or systemic infections
Cholestasis, Lantana poisoning cattle
Cholelithiasis
Cholelithiasos
Icterus/Jaundice
Hepatic biliruben retention
Cutaneous necrosis
Photosensitisation
Acquired porto-systemic shunting due to portal hypertension
Coagulopathy - epicardial ecchymoses in acute fatal Cestrum poisoning in cow
