HISTOLOGY OF LIVER .pptx

basics of liver

1. Dr.N.Manjula First year postgraduate Department of Pathology HISTOLOGY OF LIVER

2. It is an accessory digestive gland. Modified exocrine gland. It has double blood supply. Liver

3. It is surrounded by thin connective tissue capsule. It is divided into lobes : Right, Left, Caudate, Quadrate. Hepatic artery, Portal vein, Bile duct @ PORTA . INTERLOBULAR SEPTA . Gross Histology

4. LOBULES : THE STRUCTURAL AND FUNCTIONAL UNIT OF LIVER. Cross section of each lobule is hexagonal . At the corners of the hexagon are the small triangular area of connective tissue that contain PORTAL TRIADS. In the center of each hepatic lobule is a central vein , it drains blood from tubules into hepatic veins. Microscopic organization

5. HEPATOCYTES Radiating from the central vein are HEPATOCYTES, arranged in plates. These are polyhedral cells having spherical nuclei(centrally located) with 1 or 2 nucleoli. {HCC – primary hepatic neoplasia } Cytoplasm – eosinophilic and contain fine basophilic granule representing RER

6. SINUSOID Between the plates of hepatic cells are the blood passages called as sinusoids. Lined by an endothelium which has fenestrations. The flow of blood in sinusoid is from periphery towards central vein.

7. PORTAL TRIAD HEPATIC ARTERIOLE : one to three layers of smooth muscle cells, relatively small lumen. PORTAL VENULE : usually larger collapsed lumen. BILE DUCTULE : lined by simple cuboidal to columnar epithelium. Connective tissue – collagen type 1 – blue fibres on trichrome stain.

8. The liver is covered by GLISSON’S capsule (connective tissue). {SUB CAPSULAR HEMATOMA}

9. 1.Classical lobule: It has central vein located at the center . Portal triads at the edges. The blood flows from periphery to center . The bile secretion is from center towards periphery. Types of liver lobules

10. 2.Portal lobule : It is the triangular area of liver parenchyma around each portal triad. In this portal triad is in center and central vein are at edges. In this blood flows from center to periphery and bile secretion drains into central duct.

11. 3.Liver acinus : It is elliptical in shape. It includes portions of two neighbouring classical liver lobules. In the center are the terminal branches of hepatic arteriole and portal venule .

12. Each acinus is divided into three zone: Zone 1 : close to blood vessels. Zone 2 : between one and three. Zone 3 : close to central vein. Zones

13. Zone 1 supplied with most oxygenated blood and zone 3 gets the least. Degeneration secondary to hypoxia is first observed in zone 3. Degeneration due to toxic damage is first observed in zone 1. IMPORTANCE OF ZONE

14. Interspersed amongest the sinusoids are the KUPFFER CELLS (hepatic macrophages)

15. The surface of liver cell is seperated from the endothelial lining of the sinusoid by SPACE OF DISSE .

16. Hepatic stellate cells, found in perisinusoidal space. Involved in storage of vitamin A and Lipid. {HYPERVITAMINOSIS ‘A’} ITO CELLS

17. Early evidence is appearance of steatosis manifested by accumulation of lipid in form of large cytoplasmic vacuoles displacing the nucleus to one side. ALCOHOLIC HEPATITIS

18. Disruption of liver architecture. Formation of regenerating nodules. Seperated by fibrous bands . MASSON’S TRICHROME – FIBROUS TISSUE CIRRHOSIS

19. Hep Par1 Glypican-3 p-CEA AFP IHC MARKERS

20. GP PAL – TEXTBOOK OF HISTOLOGY {3E} INDERBIR SINGH – TEXTBOOK OF HUMAN HISTOLOGY {6E} NETTER’S – ESSENTIAL HISTOLOGY {3E} WHEATER’S – A TEXT ATLAS REVIEW OF HISTOPATHOLOGY {5E} REFERENCES

21. THANK YOU