• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Histology of Liver, Gall bladder, pancreas
 

Histology of Liver, Gall bladder, pancreas

on

  • 417 views

 

Statistics

Views

Total Views
417
Views on SlideShare
417
Embed Views
0

Actions

Likes
0
Downloads
301
Comments
1

0 Embeds 0

No embeds

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

11 of 1 previous next

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
  • Dear all,
    Please add your comments to further the quality of my presentations.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Histology of Liver, Gall bladder, pancreas Histology of Liver, Gall bladder, pancreas Presentation Transcript

    • HISTOLOGY OF LIVER, PANCREAS AND GALL BLADDER Dr.GURUDASAN 22.02.14
    • LIVER LARGEST GLAND IN THE BODY (1500G)  IInd HEAVIEST ORGAN AFTER SKIN  It has two types of blood supply - portal vein (70%) - Hepatic artery (30%) 
    • FUNCTIONS Synthesis & secretion of bile  Excretion of bilirubin into the bile  Synthesis and secretion of plasma proteins  Storage of glucose  Detoxification of various drugs  Haemopoeisis in fetuses  Clearing the cellular debris and particulate material by phagocytic functions of kupfer cells 
    • PARENCHYMA - HEPATOCYTES Sinusoids Central vein Hepatic artery Bile canaliculi Portal vein Space of disse Kupffer cell Bile duct
    • STRUCTURE Liver is completely invested by a fibrous capsule called “Glisson’s capsule” that lies deep to peritoneal covering (mesothelium).  Glisson’s capsule is thickened at the porta hepatis and sends trabeculae into the interior dividing the parenchyma into incomplete lobules.  The trabeculae carry branches of hepatic artery, portal vein, hepatic duct and lymphatics and are called portal tract or portal space or portal canal. 
    • LIVER LOBULE     It forms the structural and functional unit of the organ Hexagonal in shape It has a vein at the centre, the central vein Portal tracts contain connective tissue derived from Glisson’s capsule, containing portal triad i.e Branches of portal vein, hepatic artery and an interlobular bile duct.
    • LIVER LOBULE (CONTD..) Hepatocytes are arranged in one call thick plates radiating from the central vein towards the periphery of the lobule.  The irregular spaces between the hepatic plates are occupied by liver sinusoids which are lined by discontinuous fenestrated endothelial cells. 
    • LIVER LOBULE (CONTD..)    Some of the endothelial cells are modified to form phagocytic cells called kupfer’s cells, which phagocytose worn out RBCs. The sinusoids are seperated from the underlying plates of hepatocytes by a perisinusoidal space of disse. The absorbed nutritive materials and O2 present in mixed blood percolates through the discontinuous endothelial wall and comes into direct contact with hepatocytes through the space of disse.
    • LIVER LOBULE (CONTD..) The blood flows from periphery to centre.  Bile flows from centre to periphery.  The sinusoids are irrigated by mixed arterial blood from hepatic artery and venous blood from portal vein. The blood then flows towards central vein — sublobar vein — hepatic vein — IVC. 
    • HEPATOCYTES Hepatocytes are polyhedral cells having one or two spherical nuclei with well developed nucleoli.  Constitutes 80% of liver volume.  Life span:5 months and are capable of regeneration. 
    • HEPATOCYTES (CONTD)…     The polyhedral cells may have five to twelve sides and are about 20-30 µm in width. These cells form hepatic cords, which may branch and anastomose frequently. Some sides of the cells are exposed to the sinusoids and some cells which are not exposed to sinusoids show infolding between adjacent cells to form bile canaliculi. These bile canaliculi form network within the cell plates.
    • HEPATOCYTES (CONTD)… These bile canaliculi have no lining of their own, and are the first part of the duct system and terminate in the hepatic ductule in the portal triad through canal of Hering. These ductules unite to form large hepatic duct.  Thus bile synthesised in the liver cells flows through the duct system in a direction opposite to that of blood. i.e from the centre of the lobule to its periphery. 
    • PORTAL LOBULE - It is defined as the part of the liver parenchyma that drains bile into the hepatic ductule present at the portal triad. -It is triangular in shape and can be visualised by drawing imaginary lines connecting the central veins of three adjacent liver lobules with portal triad at the centre.
    • HEPATIC ACINUS -It is the another functional unit of liver which is irrigated by the terminal - distributing branches of portal vein and hepatic artery. -It is diamond shaped containing adjacent areas of two classical liver lobules - between the central veins. -It has three zones 1,2,3. Zone 1 – close to afferent blood vessels and Zone 2 – Intermediate zones Zone 3 – close to central vein
    • Sublobular vein Portal vein Central vein sinusoids Bile canaliculus Portal triad Space of Disse Kupffer cell
    • Sublobular vein Classic lobule Portal lobule Central vein Portal acinus Portal triad
    • GALL BLADDER TEMPORARY STOREHOUSE OF BILE AND CONCENTRATES IT BY WATER REABSORPTION.  CONSISTS OF - MUCOSA - FIBROMUSCULAR LAYER - SEROSA/ADVENTITIA 
    •  MUCOSA: - It includes the lining epithelium of simple columnar variety - Lamina propria rich in elastic fibres and blood vessels. - Presence of microvilli gives brush border appearance to the epithelium under light microscope. - Microvilli facilitates absorption of water.
    • Mucosa thrown into small folds when the bladder is empty.  Muscularis mucosa and submucosa are absent. 
    • FIBROMUSCULAR LAYER: - This layer consists of circularly arranged smooth muscle fibres intermixed with connective tissue rich in elastic fibres. SEROSA/ADVENTITIA: Fundus and lower surface of body of gall bladder is covered by peritoneum (serosa), Upper surface is attached to the fossa for gall bladder by means of connective tissue (adventitia)
    • PANCREAS Accessory gland of digestion.  It has both exocrine and endocrine portions.  Exocrine portion – serous acini arranged in many lobules.  Endocrine portion – Islets of langerhans, abundant in the tail region of pancreas. 
    • EXOCRINE PANCREAS - Pancreas is covered by a thin layer of loose connective tissue capsule. - Thin septa arise from this to divide the gland into many small lobules. - Pancreatic acini are serous in nature. - Intercalated ducts begin within the acini. - Shows all the features of a serous secreting cell.
    • Cells have centrally placed round nucleus.  Infranuclear region – Intensely basophilic (ER)  Supranuclear region – secretory granules called zymogen granules.  Centroacinar cellscuboidal cells, represents intra-acinar part of the intercalated duct.  Intercalated duct--intralobular ducts--interlobular duct ---main pancreatic duct 
    • Intralobular duct Islet cells of Langerhans Intercalated duct capillary Pancreatic acinus Zymogen granules
    • The exocrine part of the pancreas secretes pancreatic juice (alkaline in nature), rich in digestive enzymes into the duodenum.  Secretion is controlled by the hormones like secretin and cholecystokinin. 
    • ENDOCRINE PANCREAS It is formed by small groups of cells(Islands) which are scattered among the acini of exocrine pancreas. These are called “islets of langerhans”  These islets are lightly stained with H&E, thus can be differentiated from acini, which are darkly stained. 
    • The islets contain five kinds of cells, which is distinguishable by special stains, but not by H&E. 1. Alpha cells: -Form 20% of total population - are large cells with oesinophilic granules - Found at the periphery of islets. - secrete glucagon, that increases glucose level in blood 
    •  Beta cells: - Form 70% of the population - are small cells with basophilic granules - found mostly at the centre - secrete insulin which decrease glucose level in blood
    • Delta cells: - Forms 5% of the population - Secrete somatostatin, which suppresses secretion of Insulin and glucagon. F or PP cells: - Secrete pancreatic polypeptides which regulate acinar cell secretion. G cells – release gastrin which stimulates secretion of HCL in stomach. 
    • APPLIED ANATOMY  - - Cirrhosis of liver: Necrosis of liver cells. These dead cells are replaced by fibrous tissue. Aetiological factors: - Chronic alcoholism - drugs, chemicals - hepatitis virus - Autoimmune liver diseases
    • WILSON’S DISEASE
    •  - - Gall stones and jaundice: Due to presence of higher concentration of bile acids. Gall stones obstruct the bile duct leading to jaundice.
    • Diabetes: - Due to impaired function of beta cells in the islets of langerhans. - In this condition cells are unable to produce required amount of insulin leading to high levels of glucose in blood. Types: I) IDDM (type 1) II) Non – IDDM (Type II) 
    • Thank you