3. Liver is a large solid organ situated into the upper quadrant of abdominal cavity.
In living subject it is reddish brown in colour and soft in consistency.
The weight in male is about 1600 g and in female it is 1300 g.
Dimension is 17cm height and 15- 20 cm width.
Location – it occupies whole of hypochondriac region,a greater part of
epigastrium and extends upto left hypochondriac region.
4.
5. External features
Consists of five surfaces-
1. Anterior surface
2. Posterior surface
3. Superior surface
4. Inferior surface
5. Right surface
6. Anterior surface
It is triangular in shape and slightly convex.
It is related with-
1. Xiphoid process
2. Anterior abdominal wall
3. Diaphragm on each side
4. Falciform ligament
7.
8. Posterior surface
It is triangular in shape.it is slightly concave in middle.
It is related with-
1. Diaphragm and suprarenal gland.
2. Coeliac trunk,phrenic artery and portal vein.
9. Superior surface
It is quadrangular in shape.it is concave in middle.
It is related with-
1. Diaphragm
2. Heart
10.
11. Inferior surface
It is quadrangular in shape.
It is related with-
1. Stomach
2. Umbilical vein
3. Lesser omentum
4. Pylorus
5. Duodenum
6. Colon
7. kidney
12.
13. Right surface
It is quadrangular in shape.
It is related with-
1. Diaphragm
2. Pleura
3. Lungs
14. One prominent border
Inferior border- it is sharp anteriorly where it separates anterior surface from
inferior surface.
It has notch for ligamentum teres and notch for gallbladder.
15. Lobes of liver
Liver contains two lobes-
1. Right lobe
2. Left lobe
16.
17. Right lobe
It is larger than left lobe. It is 5/6th of liver.
It is again divided into two lobes-
1. Caudate lobe- situated in posterior surface.
2. Quadrate lobe- situated in inferior surface.
18. Porta hepatis
It is a deep transeverse fissure present between caudate and quadrate lobe .
It is present in inferior surface of right lobe.
Through it passes portal vein,hepatic artey,lymph vessels,hepatic nerve and
hepatic ducts.
19.
20. Left lobe
It is smaller than right lobe. It is 1/6th of liver.
It is flattened.
A round elevation called tuber omentale present near fissure for ligamentum
venosum.
21.
22. Peritoneal relation
The liver is covered by peritoneum except some areas-
1. The triangular bare area
2. Groove for inferior vena cava
3. Fossa for gallbladder
4. Porta hepatis
5. Triangular area for falciform ligament
23.
24. Histology
Hepatic lobes are made up of many hepatic lobule. These are the structural unit of
liver.
About 50000 to 100000 lobules are present 8n liver.
Lobules are made up of hepatocytes.
Hepatocytes and hepatic plates- Hepatocytes are arranged in column to form
hepatic plates. Each plate consists of two column of cells. Betwwen two columns
lies bile canaliculus.
Between neighboring plates lies a blood space called sinusoids.
Kupffer cells are also present.
25.
26. Portal triode
Each lobule many portal trode.
Each portal triode consists of-
1. A branch of hepatic artery
2. A branch of portal vein.
3. A branch of bile duct
27.
28. Development of liver
In embryonic stage of 3rd week from the caudal end of foregut an endodermal
hepatic bud arises.
It is endodermal in origin.
Bud elongates and gives a small bud at right side called pars cystica and main part
is called pars hepatica.
Pars cystica develops in gall bladder and cystic duct.
Pars hepatica developes in liver.
The development process completes in 8th week.
29.
30. Ligaments of liver
Two types of ligaments are present-
1. Peritoneal or false ligaments
2. Non peritoneal or true ligament.
31. False ligament
1. Falciform ligament
2. Coronary ligament
3. Right triangular ligament
4. Left triangular ligament
5. Lesser omentum
34. Arterial supply of liver
About 1.5 ltr of blood is supplied to liver. In which 20% is supplied by hepatic
artery and 80% is supplied by portal vein.
Hepatic atery and portal vein divides into interlobular branch then they opens into
sinusoids where both hepatic and portal blood mixes .
39. Segments of liver
Liver can be divided into right and left functional lobe on the basis
of interhepatic distribution of hepatic artery,portal vein and bile
ducts.
Lobes are separated by plane passing through antero-posterior
surface along a line joining the cystic notch to groove of inferior
vena cava.
Right lobe is divided into anterior and posterior segment.
Left lobe is divided into medial and lateral segment.
40.
41. Biliary system
Bile is secreted from hepatocyte and empties into canaliculus.
From canali culus bile enters into tributaries of bile duct. Tributaries of
neighboring lobule unites to form small bile duct. Small duct unites to form right
and left bile duct.
After leaving liver both duct unintes to form commom hepatic duct. Bile from
common hepatic duct goes to gallbladder via cystic duct where bile stores.
For digestion bile from gallbladder comes via cystic duct into bile duct. Bile duct
joins pancreatic duct and forms hepato pancreatic duct which opens into
duodenum via ampulla of vater.
42.
43. Portal system
It is formed by union of superior mesentric vein and splenic vein.
It drains blood from whole abdomen except lower part of rectum and anal canal .
It drains spleen,pancreas,gallbladder.
It ultimately drains into inferior vena cava.
44.
45. Functions of liver
Exocrine function- secrets bile for digestion of fat.
Endocrine function- metabolism of vitamin D. Secretion of erythropoetin, somatomedin.
Metabolism of fat,carbohydrate and protein.
Glycogenesis,gluconeogenesis.
Synthesis of plasma protien.
Fatty acid synthesis from glucose.
Synthesis of lipids.
Synthesis of cholesterol.
Conversion of amonia to urea.
Metabolism of alcohol.
46. Storage of fat soluble vitamins.
Metabolism of hormone, drugs.
Excretion of bile pigment.
Phagocytosis by kupffer cells.
Hemolysis by RE system.