Liver Function 1

download Liver Function 1

of 50

  • date post

    03-Jun-2018
  • Category

    Documents

  • view

    218
  • download

    0

Embed Size (px)

Transcript of Liver Function 1

  • 8/12/2019 Liver Function 1

    1/50

    http://www.toons4biz.com/Cartoon-Liver-Pointing-Up-p/liver_cartoon_liver01x005.htm
  • 8/12/2019 Liver Function 1

    2/50

    Liver- Position

  • 8/12/2019 Liver Function 1

    3/50

    Liver Introduction

    Also calledhepar

    Largest glandin the body

    Weighs about 1600 gm in males,1300 gm

    in females

    Occupies the right hypochondrium,

    epigastrium & left hypochondrium

    Most part of the liver is covered by ribs &

    costal cartilages

  • 8/12/2019 Liver Function 1

    4/50

  • 8/12/2019 Liver Function 1

    5/50

  • 8/12/2019 Liver Function 1

    6/50

    External Features

    Wedge shaped, resembles four sided

    pyramid.

    3 surfaces- Superior, posterior & inferior.

    Inferior surfaceis well defined -also

    called visceral surface

    Inferior borderis well defined & the otherborders are rounded

  • 8/12/2019 Liver Function 1

    7/50

    External featuresEx

    Superior surfaceis attached to the

    diaphragm and anterior abdominal wall by

    falciform ligament and the free margin

    contains ligamentum teres (obli terated

    umbi l ical vein).

    Inferior and posterior surfacesare divided

    into four lobes namely right lobe, left lobe,

    quadrate lobe & caudate lobe.

    External Features

  • 8/12/2019 Liver Function 1

    8/50

  • 8/12/2019 Liver Function 1

    9/50

    Lobes of Liver

    Liver is divided into right & left lobesby

    falciform ligament ,fissure for

    ligamentum teres & fissure for

    ligamentum venosum.

    Right lobe is larger than left and has

    caudate & quadrate lobes.

  • 8/12/2019 Liver Function 1

    10/50

    Lobes of Liver

    Left lobe

    Caudate lobe

    Right lobe

    Quadrate lobe

  • 8/12/2019 Liver Function 1

    11/50

    Porta Hepatis

    Portahepatis,is the hilum

    of the liver transmitting thehepatic ducts, hepatic

    artery and portal vein in

    that order from before

    backwards.

    Lesser omentumextends

    between porta hepatis and

    the lesser curvature of

    stomach.

    Porta hepatis

  • 8/12/2019 Liver Function 1

    12/50

    Lobes of Liver

    Liver is divided into right & left lobesby

    falciform ligament ,fissure for

    ligamentum teres & fissure for

    ligamentum venosum.

    Right lobe is larger than left and has

    caudate & quadrate lobes.

  • 8/12/2019 Liver Function 1

    13/50

    Lobes of Liver

    Left lobe

    Caudate lobe

    Right lobe

    Quadrate lobe

  • 8/12/2019 Liver Function 1

    14/50

    Porta Hepatis

    Portahepatis, is the hilum

    of the liver transmitting thehepatic ducts, hepatic artery

    and portal vein in that order

    from before backwards.

    Lesser omentumextendsbetween porta hepatis and

    the lesser curvature of

    stomach.

    Porta hepatis

  • 8/12/2019 Liver Function 1

    15/50

    Biliary Apparatus

    Gall bladder.

    Cystic duct.

    Right and left hepatic ductswhich unite to form

    common hepatic duct.Bile duct formed by the union of cystic duct

    and common hepatic duct.

  • 8/12/2019 Liver Function 1

    16/50

    DUCT SYSTEMBile secreted by

    liver carried to the

    gall-bladder by the

    cystic duct orpoured directly

    into the duodenum

    by the common

    bile duct to aid

    digestion

  • 8/12/2019 Liver Function 1

    17/50

    Functional Unit of Liver

    Hepatic lobules

    Hexagonal structures,

    with six portal triads at

    the corners of the

    lobules and a central

    vein in the middle

    Connective tissue

    capsule (Glissons

    capsule) is scanty

  • 8/12/2019 Liver Function 1

    18/50

  • 8/12/2019 Liver Function 1

    19/50

    Functional Unit

    Each lobule is made of cords of liver cells

    (hepatocytes) separated by sinusoids

    Cells are arranged in plates which branch

    & anastomose

    Periphery of each lobule has angular

    intervals called portal canals containingbranch of portal vein, hepatic artery &

    interlobular bile duct forming a portal triad

  • 8/12/2019 Liver Function 1

    20/50

  • 8/12/2019 Liver Function 1

    21/50

    Hexagonal lobules of liver with hepatocytes

    21

    Portal triad

  • 8/12/2019 Liver Function 1

    22/50

    22

  • 8/12/2019 Liver Function 1

    23/50

    Cell Types in Liver

    C t l i I th

  • 8/12/2019 Liver Function 1

    24/50

    Central vein: In the

    center of the lobule.

    Receives blood from

    the sinusoids. Kupffer cells:

    Reticuloendothelial

    cells in the walls of the

    sinusoids of the liverThe Kupffer cells are

    phagocytic cells which

    destroy worn- out wbc,

    rbc , bacteria &foreign matte

    24

    Central vein

    Kupffer cells:

    P th f bil ithi th li

    http://www.usc.edu/hsc/dental/ghisto/gi/c_90.htmlhttp://www.usc.edu/hsc/dental/ghisto/gi/c_90.htmlhttp://www.usc.edu/hsc/dental/ghisto/gi/c_90.html
  • 8/12/2019 Liver Function 1

    25/50

    Pathway of bile within the liver

    Bile originates as secretions from the hepatocytes, whichcollect in channels called

    Bile canaliculi (tiny passages contained within each cord.)

    Canal of Hering, bile ductules at the periphery of classicliver lobules

    Bile duct- located in the portal areas

    CoH: Canal of Hering.

    F ti l U it f Li

  • 8/12/2019 Liver Function 1

    26/50

    Functional Units of Liver

    Classic Lobule

    Portal LobuleHepatic Acini (Rappaport)

    - a direct correlation between

    blood supply and metabolism

    Classic Lobule

    Model- Anatomical

    Hexagonal in shape withthe portal triads.at the

    periphery and central vein

    at the centre.

  • 8/12/2019 Liver Function 1

    27/50

    Portal lobules

    Triangular in shape, centered around the portal triad

    Based on bile flowIn this concept of liver lobulation, the bile duct is in the

    centre of the lobule

    Bile duct

    H ti i ( f R t)

  • 8/12/2019 Liver Function 1

    28/50

    Hepatic acinus (of Rappaport)

    Based on blood flow

    The smallest functional unit of the liver, a mass of liverparenchyma that is supplied by terminal branches of the

    portal vein and hepatic artery and drained by a terminal

    branch of the bile duct (portal triad vessels).

    Diamond- shaped region encompassing triangular

    sections of two adjacent classic liver lobules with apices

    that are the central vein.

  • 8/12/2019 Liver Function 1

    29/50

    The liver (portal) acinus

    provides the bestcorrelation among blood

    perfusion, metabolic

    activity, and liver pathology.

  • 8/12/2019 Liver Function 1

    30/50

  • 8/12/2019 Liver Function 1

    31/50

    G l M t b li F ti

  • 8/12/2019 Liver Function 1

    32/50

    General Metabolic Functions

    Carbohydrate metabo l ism

    Maintainence of the blood glucose level:

    Glycogenesis(glycogen synthesis), storage

    Glygenolysis (glycogen breakdown)

    Gluconeogenesis

    G l M t b li F ti

  • 8/12/2019 Liver Function 1

    33/50

    General Metabolic Functions

    Protein Metabo l ism

    Synthesis of most palsma proteins such

    as albumin & transport proteins

    Deamiation of amino acids & formation of

    urea

    G l M t b li F ti

  • 8/12/2019 Liver Function 1

    34/50

    General Metabolic Function

    Lip id metabo l ism

    Oxidation of fatty acid to ketone bodies

    Synthesis of cholesterol & cholesterolesters

    Synthesis of

    lipoproteins,triglycerides,phospholipids

    synthesis of bile acids

  • 8/12/2019 Liver Function 1

    35/50

    Cholesterol metabolism

    1. Synthesizes cholesterol and releases it

    into the blood

    2. Secretes plasma cholesterol into the

    bile

    3. Converts plasma cholesterol into bilesalts

    Synthetic Functions

  • 8/12/2019 Liver Function 1

    36/50

    Synthetic Functions

    Hepatocy tes synthesize:

    plasma proteinsexcept immunoglobulins

    most coagulation factorssuch as fibrinogen

    & factorII,V,VII,IX,X XI, XII)

    Cholesteterol , lipoproteins (VLDL,HDL)

    primary bile acids

    St f Vit i

  • 8/12/2019 Liver Function 1

    37/50

    Storage of Vitamins

    Hydroxylation of calciols to calcidiols,

    splitting of carotene to retinol

    The liver represent a store of lipophilic

    vitamins and cobalamin (B12)

    Detoxification and Excretion

  • 8/12/2019 Liver Function 1

    38/50

    Detoxification and Excretion

    Subs tances that are inact ivated & exc reted by

    the liver inc lude:

    Bilirubin

    Bile acids

    Steroid hormones

    Many drugs

    Toxins

    T f ti f h

  • 8/12/2019 Liver Function 1

    39/50

    Transformation of hormones

    inactivation of steroid hormones

    hydrogenation, conjugation

    inactivation of insulin and glucagon

    inactivation of catecholamines and

    iodothyronines - conjugation

    dehydrogenation of cholesterol to 7-

    dehydrocholesterol and 25-hydroxylation of calciols play an essential role

    in calcium homeostasis

    M t b li f bili bi

  • 8/12/2019 Liver Function 1

    40/50