Clinical Pathology Unit 6

Liver

Tucked inside is the gallbladder

Domestic species- lobed (4-5 lobes)

Liver cells

hepatocytes

Cavity in between is called

sinusoid

Hepatic artery

supplies oxygen and nutrients to the liver via oxygenated blood

¼ of blood

goes into the liver

¾ of blood

is deoxygenated blood from other organs (needs to be detoxified by the liver)

Hepatic vein

exit and cleans up blood

Hepatocytes

make up 60-70% of cell tissue

Hepatocytes contain

liver enzymes- break down

Preform major functions of the liver

Kupfer cells

Digest RBCs

Stellate cells

store fat and vitamin A

order of liver

Bile duct system->bile duct->gallbladder

- in hepatic space (sinusoid)

Functions of liver

Formation of bile

Detoxification

Metabolism of carbs and fat

Process protein

Production of blood proteins

Bile

Emulsify fat, break into smaller globules and aids in fat digestion by pancreatic enzymes (Lipase)

Detoxification

Done by the liver enzymes

Enzymes

aid in the breakdown of toxins and drugs

Metabolism of carbs and fat

Glucose

Glycogen

Glycogen

Excess glucose

Excess is stored as fat

Process can go both ways

Process protein

Gluconeogenesis

convert animo acids into glucose by removing nitrogen

Biproduct of gluconeogenesis

ammonia- eliminated as urea = urine (kidney)

Production of blood proteins

Formed in liver

Over 200 blood proteins

3 major ones

Albumin

Fibrinogen

Globulin

Albumin

Must abundant

Transports

Maintains osmotic pressure within blood pressure

Fibrinogen

Converted to fibrin to clot

Globulin

Immunoglobulins- titers

titers

how much antibodies are left

-Igm

-IgG

In house test that gives amount of protein in the blood

Pack cell volume

Total solid protein- refractometer

Total solid protein decreased amount

can be liver, intestinal or kidney disease

Total solid protein increased amount

dehydration

Bile pigments order

RBC lyces-> Biliverdin->converted by macrophages->unconjugated bilirubin->liver-> conjugated bilirubin->bile ducts + gallbladder

Unconjugated bilirubin

Not water soluble

Loosely bound to albumin

Liver in bile pigment order

Conjugation to make it water soluble- done by glucuronic acid

bile ducts + gallbladder

50% goes to intestines then back to liver

Other 50% goes to intestines and bacteria is converted into urobilinogen

Urobilinogen 50% goes to

kidney and be excreted in urine

Urobilinogen other 50% goes to

Bulk of it stays in the intestines and becomes stercobilin and is excreted in feces

Bile pigments testing

Total bilirubin

Conjugated bilirubin (direct)

Unconjugated bilirubin (indirect-calculated)

Conjugated bilirubin

Increase indicates a bile duct blockage or issue with gallbladder

Unconjugated bilirubin

Increase indicates a liver issue or hemolytic disease

ALT- alanine aminotransferase

Dogs, cats and primates the major source of ALT is the hepatocyte

SD- sorbitol dehydrogenase

Liver specific in all domestic species

Not stable within the blood so blood should be processed within 12 hours for accuracy

AST- aspartate aminotransferase

Found in hepatocyte

Found in RBCs, cardiac and skeletal muscle, kidney, pancreas

Not liver specific, interpret with other tests

CK- creatine kinase

Becomes elevated when there is inflammation of muscle

Ran with AST

What liver enzymes point to bile duct or gallbladder issues

AP/ALK/ALKP- Alkaline phosphate

GGT- gamma glutyl transpeptidase (large animal)

Ammonia test

Can't be done in house

Ammonia degrades rapidly

Liver disease can cause build up in the bloodstream

-Causes seizers