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Created page with '====Causes==== *severe metabolic disturbances [as seen in degenerative pathology link?] *toxic substances [link?] *nutritional deficiencies *action of micro-organisms ====Histol…'
====Causes====
*severe metabolic disturbances [as seen in degenerative pathology link?]
*toxic substances [link?]
*nutritional deficiencies
*action of micro-organisms
====Histological patterns====
*[[Liver - Anatomy & Physiology|Liver]] cell necrosis has been classified on an anatomic basis with reference to the distribution of the lesion
=====Random foci (focal)=====
*microscopic foci of necrosis not related to any particular part of the [[Liver - Anatomy & Physiology|liver]] lobule
*can be due to a variety of insults
**systemic viral, bacterial,and parasitic infections
**result of bacteria being absorbed from the gut
*examples
**Equine herpes virus infection
***in aborted foetuses
**Salmonellosis
***in calves
**Toxoplasmosis (miliary)
***in dogs and cats
=====Zonal necrosis=====
*necrosis occurring mainly in a part of the lobule and further subdivided according to whether the lesions are situated centrally, peripherally, or in the mid-zone of the lobule
*due to anoxia
======Periacinar (centrilobular)======
*most common
*main reason is because the hepatocytes in this zone are furthest away from the incoming blood supply
**therefore less oxygenated and relatively anoxic
*reported to contain the greatest number of enzymes responsible for metabolising sunstances to more toxic metabolites capable of killing the hepatocytes
*hypoxic states and toxic substances predominate in this type of necrosis
*some viral conditions cause this necrosis
**eg Infectious Canine Hepatitis
*poisons
**eg carbon tetrachloride
======Midzonal======
*rare
*in pigs with alfatoxicosis
*'Yellow Fever' in man
======Periportal (centroacinar)======
*rare
*eg phosphorous poisoning
=====Massive necrosis=====
*necrosis of large areas of [[Liver - Anatomy & Physiology|liver]] cells comprising many lobules (complete acinus or several acini) and sometimes involving almost the whole organ
*some cases of ICH infection or carbon tetrachloride poisoning, the severity of the injury replacing the zonal pattern
======Subacute cytolytic necrosis======
*a condition in the dog
*aetiology is entirely unknown
*Clinical
**acute abdominal pain
**collapse
**invariably jaundice
*Gross
**[[Liver - Anatomy & Physiology|Liver]] is normal or reduced in size
*Microscopically
**severe necrosis
======''Hepatosis dietica''======
*similar condition to subacute cytolytic necrosis
*occurs in rapidly growing pigs
*related to diet
**fed on large quantities of grain concentrates
**poor quality or low quantity protein supplements
*Cause
**nutritional deficiencies of selenium and Vitamin E, and probably amino acids
**triggering mechanism is environmental stress[[Category:Liver_-_General_Pathology]]
*severe metabolic disturbances [as seen in degenerative pathology link?]
*toxic substances [link?]
*nutritional deficiencies
*action of micro-organisms
====Histological patterns====
*[[Liver - Anatomy & Physiology|Liver]] cell necrosis has been classified on an anatomic basis with reference to the distribution of the lesion
=====Random foci (focal)=====
*microscopic foci of necrosis not related to any particular part of the [[Liver - Anatomy & Physiology|liver]] lobule
*can be due to a variety of insults
**systemic viral, bacterial,and parasitic infections
**result of bacteria being absorbed from the gut
*examples
**Equine herpes virus infection
***in aborted foetuses
**Salmonellosis
***in calves
**Toxoplasmosis (miliary)
***in dogs and cats
=====Zonal necrosis=====
*necrosis occurring mainly in a part of the lobule and further subdivided according to whether the lesions are situated centrally, peripherally, or in the mid-zone of the lobule
*due to anoxia
======Periacinar (centrilobular)======
*most common
*main reason is because the hepatocytes in this zone are furthest away from the incoming blood supply
**therefore less oxygenated and relatively anoxic
*reported to contain the greatest number of enzymes responsible for metabolising sunstances to more toxic metabolites capable of killing the hepatocytes
*hypoxic states and toxic substances predominate in this type of necrosis
*some viral conditions cause this necrosis
**eg Infectious Canine Hepatitis
*poisons
**eg carbon tetrachloride
======Midzonal======
*rare
*in pigs with alfatoxicosis
*'Yellow Fever' in man
======Periportal (centroacinar)======
*rare
*eg phosphorous poisoning
=====Massive necrosis=====
*necrosis of large areas of [[Liver - Anatomy & Physiology|liver]] cells comprising many lobules (complete acinus or several acini) and sometimes involving almost the whole organ
*some cases of ICH infection or carbon tetrachloride poisoning, the severity of the injury replacing the zonal pattern
======Subacute cytolytic necrosis======
*a condition in the dog
*aetiology is entirely unknown
*Clinical
**acute abdominal pain
**collapse
**invariably jaundice
*Gross
**[[Liver - Anatomy & Physiology|Liver]] is normal or reduced in size
*Microscopically
**severe necrosis
======''Hepatosis dietica''======
*similar condition to subacute cytolytic necrosis
*occurs in rapidly growing pigs
*related to diet
**fed on large quantities of grain concentrates
**poor quality or low quantity protein supplements
*Cause
**nutritional deficiencies of selenium and Vitamin E, and probably amino acids
**triggering mechanism is environmental stress[[Category:Liver_-_General_Pathology]]