Liver Flashcards
Liver is _____ gland
Largest and ExoEndoCrine Gland
Functions of Liver are
- It secretes bile and stores glycogen.
- It synthesizes the serum proteins and lipids.
- It detoxifies blood from endogenous and exogenous substances (e.g., toxins, drugs, alcohol, etc.) that enter the circulation.
- It produces hemopoietic cells of all types during fetal life.
Location Of Liver
Occupies Right Hypochondrium, upper part of Epigastrium and part of Left Hypochondrium upto midclavicular line.
It is under the cover of ribs extending upwards as far as 5th rib anteriorly on right and 5th intercostal on left both below the nipple
Shape, Size , Color
Wedge shaped resembling 4 sided pyramid with base directed towards right and the apex directed towards left.
Weight In males: 1.4 to 1.8 kg. In females: 1.2 to 1.4 kg. In newborn: 1/18th of the body weight. At birth: 150 g. Proportional weight: In adult 1/40th of the body weight
Red Brown in Color
Wedged shaped liver has __ well defined surfaces and __ defined borders
2 Surfaces ( Diaphragmatic & Visceral ) 1 Border ( Inferior Border )
Diaphragmatic Surface : Shape and texture
It includes the smooth peritoneal areas which face superiorly, anteriorly and to the right, and rough bare area ( devoid of peritoneum ) which faces posteriorly
Diaphragmatic Surface : Vessels and Ligaments
IVC : Embedded in Deep Sulcus of Bare Area; Roofed by ligament of IVC having hepatic tissue making sulcus into tunnel
The peritoneal ligaments are
Coronary, left and right triangular and falciform ligaments.
Visceral Surface : Shape and Texture
The visceral surface is relatively flat or concave. It is directed downward, backward, and to the left. It is separated in front from the diaphragmatic surface by the sharp inferior border and behind from the diaphragm by the posterior layer of
coronary ligament.
Features on the visceral surface are:
Fossa for the gallbladder.
Fissure for the ligamentum teres hepatis.
Porta hepatis.
Visceral surface is covered by peritoneum except at
Fossa for the gallbladder
Inferior Border features :
Separates diaphragmatic surface and visceral surface
Rounded laterally separating Right lateral from inferior surface
Thin and sharp where it separates anterior and inferior surface
Lies at transpyloric plane
The 2 notches in inferior border are :
- Notch for ligamentum teres or interlobar notch
2. Cystic notch
Anatomical Lobes:
On Diaphragmatic Surface : Divided into two
lobes, right and left, by the attachment of the falciform ligament
On Visceral Surface : Divided into four
lobes: (a) right lobe, (b) left lobe, (c) quadrate lobe, and (d) caudate lobe by fissures and fossae present on this Surface
(Viz. fissures for ligamentum teres and ligamentum venosum, porta hepatis, groove of the IVC and fossa for the gallbladder).
Physiological Lobes : Based on?
Based on the intrahepatic
distribution of branches of the bile ducts, hepatic artery, and portal vein.
The physiological lobes are :
The liver is divided into right and left physiological lobes by an imaginary sagittal plane/line (Cantlie’s plane/line).
On the posteroinferior surface this plane passes through the fossa for gallbladder, to the groove for IVC.
On the anterosuperior surface of the liver, this plane passes from the IVC to the cystic notch present a little to the right of the falciform ligament
Each lobe has its own ?
Primary branch of hepatic artery and portal vein and is drained in its own hepatic duct
What are Hepatic Segments and their number
These are structural units of the liver and are 8 in number
The right physiological lobe is divided in to how many segments
It is divided into Anterior and Posterior Segments which is further divided into Upper and Lower Segments
Therefore 4 segments
The left physiological lobe is divided into how many segments
The left lobe is divided into Medial and lateral which is further divided into upper and lower segments
Naming and numbering of Hepatic Segments
Medial Superior : I Lateral Superior : II Medial Inferior : III Lateral Inferior : IV Anterior Inferior : V Posterior Inferior : VI Posterior Superior : VII Anterior Superior : VIII
Couinaud’s segments:
According to nomenclature of
Couinaud, the hepatic segments are numbered I to VIII . I to IV in the left hemiliver and V to VIII in the right
hemiliver. According to this nomenclature, the segment I corresponds to the caudate lobe and segment IV corresponds to the quadrate lobe.
Blood supply of Segments
Segment I to IV of the left lobe are supplied by the left
branch of hepatic artery, left branch of portal vein and drained by left hepatic duct.
The segments V to VIII of right lobe are supplied by right hepatic artery, right branch of portal vein and drained by right hepatic duct.
False Ligaments
- Falciform ligament.
- Coronary ligament.
- Right triangular ligament.
- Left triangular ligament.
- Lesser omentum
True Ligaments
- Ligamentum teres hepatis.
2. Ligamentum venosum
Ligamentum Teres Hepatis is remnant of ?
The obliterated left umbilical vein
Ligamentum Venosum is remnant of ?
The obliterated ductus venosus which in fetal life connects the left branch of the portal vein with the IVC.
Blood supply of Liver
Hepatic Artery and Portal Vein ( Rich in nutrients )
80% of blood ( 1/3rd of cardiac output ) is delivered through the portal vein and 20% is delivered through the hepatic artery.
Venous Drainage of Liver
(a) left hepatic vein between medial and lateral
segments of the left true lobe,
(b) middle hepatic vein
between true right and left true lobes, and
(c) right hepatic vein between anterior and posterior segments of the right true lobe.
They emerge in the upper part of the groove for IVC and open directly in the IVC, just below the central tendon of the diaphragm.
Nerve Supply
The sympathetic fibres are derived from
the coeliac plexus.
The parasympathetic fibres are derived from the hepatic branch of the anterior vagal trunk.
Factors keeping Liver in place
- Hepatic veins connecting the liver to the IVC.
- Intra-abdominal pressure maintained by the tone of abdominal muscles.
- Peritoneal ligaments connecting the liver to the
abdominal walls.
