Complete Anatomy of Liver

Liver

• Liver is the largest internal organ of the body.
• Liver is the largest exocrine gland of the body.
• Liver is the main heat producing organ of the body.
• 1500 ml/min blood pass-out from the liver.
• 400 ml blood always present in the liver.
• Chief cells of the liver are called hepatocyte which forms 80% mass of the liver.

In this article we are discussing about on these topics...

1. Synonym
2. Location
3. Measurement
4. Presenting parts
5. Relation
6. Ligaments
7. Porta hepatis
8. Hepatic segments
9. Histology
10. Functions
11. Blood supply
12. Lymphatic drainage
13. Nerve supply
14. Applied anatomy

Front view of the liver

Synonym

Haper, hepta, biochemical lab, kitchen of the body.

Location

Right and left hypochondriac region and epigastric region.

Posterior and inferior view of the liver

Measurements

Weight - 1200 - 1500gms ( male - 1400-1600, female - 1200 - 1400gms)

Length - 26cm in male and 25cm in female average
Thickness - 22cm in adult male and 21cm in adult female average
Height -  7cm average
Color - Reddish brown
Consistency - soft
Quantity - one in number
Shape - wedge shape

Presenting parts

Surfaces ( 5 ) - Superior, Inferior, Anterior, Posterior, Right.

Border - Inferior

Lobes -

a. Necessary lobes - Right lobe and left lobe.

b. Accessory lobes - Caudate and quadrate lobe.

Surfaces

Superior surface

It is quadrilateral and shows a concavity in the middle called cardiac impression

Inferior surface

It is quadrilateral and is directed downwards and down to the left. Gastric impression, fissure for ligamentum teres, quadrate lobe, fossa for gallbladder and colic impression on it,

Anterior surface

It is triangular and slightly convex. Falciform  ligament is attached on it.

Posterior surface

It is triangular and middle part of this surface shows a concavity for vertebral column. Bare area, groove for inferior vena cava, caudate lobe, fissure for ligamentum venosum and oesophageal impression.

Right surface

It is quadrilateral and convex. it is related to the diaphragm opposite to the 7th to 11th ribs in the mid axillary  line.

Border

Inferior border

It is sharp anteriorly and interlobar notch for ligamentum teres and a cystic notch for the fundus for gallbladder present on it.

Lobes

Liver is divided into two lobes (right and left ) by the falciform ligament anteriorly and superiorly, fissure for ligamentum teres inferiorly and fissure for ligamentum venosum  posteriorly.

Right lobe

It is much larger than the left lobe and forms 5/6 part of the liver. caudate (posterior surface) and quadrate (inferior surface ) lobe present on it.

Caudate lobe 

it is situated on the posterior surface.

Quadrate lobe

It is situated on the inferior surface.

Left lobe

It is the much smaller than the right lobe and forms 1/6 part of the liver. tuber omentale or omental tuberosity present on it.

Relation

a. Peritoneal relation

Most of the liver is covered by the peritoneum except triangular bare area, groove for inferior vena cava, fossa for gallbladder, area attachment for lesser omentum  and ligamentum venosum.

b. Visceral realation

Anteriorly

Xiphoid process, anterior abdominal wall, diaphragm and falciform ligament,

Posteriorly

Inferior vena cava, ligamentum venosum, abdominal part of oesophagus, bare area and caudate lobe.

Superiorly

Diaphragm

Inferiorly

Stomach, ligamentum teres and quadrate lobe.

Relations of Posterior and inferior surface of the liver

Right

Diaphragm and mid axillary line.

Ligaments

 a. True ligaments

I. Ligamentum venosum (posteriorly) - remnant part of the ductus venosum.

II. Ligamentum teres (inferiorly) - remnant part of the umbilical cord. It is also called round ligament of the liver.

b. False ligaments

These are peritoneal folds.

These are 5 in number...

  I. Falciform ligament

 II. Coronary ligament

III. Right triangular ligament

IV. Left triangular ligament

 V. Lessor omentum

Porta heapatis

It is also called as gateway of liver.

It situated on the posteroinferior surface of right lobe of the liver.

It's length about 5cm.

Portal vein and hepatic artery passes through it.

Hepatic segments

On the basis of intrahepatic distribution of the hepatic artery, portal vein and biliary duct, liver can be divided right and left functional lobes. These lobe don't correspond to the anatomical lobes.

Right anatomical lobe is sub divided into these hepatic segments...

• Right anterior ( V and VIII )
• Right posterior ( VI and VII )

Left anatomical lobe are sub divided into these hepatic segments...

• Left lateral ( II and III )
• Left medial ( I and IV )

Segments of the liver

Histology

Histology of liver (a). Portal lobule, (b). Liver acinus

Histology of the liver

Functions

1. Metabolism - carbohydrates, fats and proteins.
2. Synthesis - bile and prothrombin.
3. Excretion - drugs, toxins, poisons, cholesterol, bile pigments, and heavy metals.
4. Protective - conjugation, destruction, phagocytosis, antibody formation and excretion.
5. Storage - glycogen, fat, vitamins ( A,D,E,K and B12 ) and minerals ( iron ).

Blood supply

Arterial supply -

• Hepatic artery - 20% blood supply for it.
• Portal vein - 80% blood supply for it.

Venous drainage -

Hepatic vein

Blood supply of the liver

Lymphatic drainage

The liver produce a large amount of lymph which is estimated 25 - 50% of total lymph.

• Hepatic lymph node
• Paracardial lymph node
• coeliac lymph node
• Thoracic duct
• Caval

Nerve supply

Hepatic nervous plexus which contain sympathetic and parasympathetic nerve fibers.

• Sympathetic fibers - celiac plexus
• Parasympathetic fibers - vagal fibers. 

Clinical Anatomy of the Liver

• Location and Examination: The liver is located in the infrasternal angle and can be examined through percussion, although it is usually not palpable due to the tone of the recti muscles and its softness.
• Position: In the median plane, the lower border of the liver lies on the transpyloric plane, about a hand’s breadth below the xiphisternal joint. In women and children, this border often projects slightly below the right costal margin.
• Liver Enlargement: The liver may enlarge towards the right iliac fossa. The spleen can also enlarge in the same direction.
• Inflammation (Hepatitis): Liver inflammation, known as hepatitis, can be infective or amoebic.
• Cirrhosis: In cases of malnutrition, liver tissue may undergo fibrosis and shrink, leading to cirrhosis.
• Liver Biopsy: A liver biopsy is performed by inserting a needle through the right 9th intercostal space, passing through both the pleural and peritoneal cavities.
• Metastasis: The liver is a common site for metastatic tumors, as venous blood from the gastrointestinal tract drains into the liver via the portal vein.
• Blood Supply: The liver receives blood from both the hepatic artery and the portal vein, which lie in the free margin of the lesser omentum. Bleeding can be controlled by compressing this area (Pringle’s maneuver).
• Liver Resection and Regeneration: Up to 80% of the liver can be safely removed during surgery, with the liver capable of regenerating within 6-12 months.
• Liver Transplantation: Liver transplants involve grafting an organ from a donor, with various anastomoses of the veins, arteries, and bile ducts. A partial liver from a healthy donor can also be transplanted.
• Portal Hypertension: In severe cases, procedures like TIPS (transjugular intraparenchymal portosystemic shunt) are used to reduce portal hypertension.
• Cirrhosis Symptoms: Advanced cirrhosis can lead to "caput medusae," where distended veins are visible around the umbilicus.

Images are copied from BD chourasia and Tortora books