VPB 121: Veterinary Physiology - II (2+1)

JAUNDICE

• lt is much a symptom  than a disease.
• It gives a yellowish tint to the  body tissues, including  the skin  and  deep tissues.
• Usual cause of jaundice is the presence of  large  quantities of bilirubin in the ECF, either free or conjugated form. 
• Normal plasma concentration of bilirubin (both free and conjugated) is about 0.5 mg/100 ml  of  plasma.
• In abnormal   conditions, it can rise up  to 40mg/100 ml. Skin may appear yellow when the concentration of bilirubin rises to about 1.5 mg/100 ml.
• Physiological classification of jaundice:
  • Haemolytic jaundice
  • Obstructive jaundice 

Hemolytic  jaundice

• It is due to excessive destruction  of  RBC  with rapid release of  bilirubin  in to the blood. In this condition excretory function of the liver is not impaired
• Plasma concentration of both free  and conjugated form of bilirubin are elevated much above the normal level .
• The rate of formation of urobilinogen in the intestine is also increased.

Obstructive jaundice   

• Obstruction in the bile ducts or damage to the liver cells leads to improper excretion of  the usual amounts of   bilirubin  in to the G.I  tract.  
• In this condition  the rate of bilirubin  formation is normal.
• The free bilirubin gets into the liver cell for  conjugation. Rupture of thebile canaliculi directly empties conjugated bilirubin   into the lymph, hence most of the plasma bilirubin are of conjugated type rather than free bilirubin.