The largest internal organ, about 1.5 kg, occupying the right hypochondrium and epigastrium beneath the diaphragm
Liver — the largest gland in the body and the largest internal organ.
Anatomy · Organs & viscera
Liver
The largest internal organ
Right upper abdomen · digestive system
The liver is the largest solid organ inside the body, a wedge-shaped, reddish-brown mass that lies mainly in the right upper abdomen, tucked under the right dome of the diaphragm and protected by the lower ribs. Its dome reaches as high as the fifth intercostal space, and its lower edge follows the right costal margin. The falciform ligament divides it on the front into a large right and a smaller left lobe, and on its underside are two more, the caudate and quadrate lobes.
How to spot them
- ▸A large wedge under the right dome of the diaphragm, extending across the midline into the left upper abdomen
- ▸The falciform ligament runs from its front surface to the abdominal wall and marks the boundary of the right and left lobes
- ▸The underside (visceral surface) has an H-shaped set of fissures marking off the caudate and quadrate lobes, with the gallbladder on the right and the porta hepatis in the middle
- ▸Impressions on the underside show its neighbours: stomach, duodenum, right kidney and right colic flexure
What to know
A sickle-shaped fold of peritoneum that attaches it to the front abdominal wall and separates its right and left lobes on the front
The falciform ligament of the liver.
Its four anatomical lobes are right, left, caudate and quadrate
The lobes of the liver — the caudate and quadrate are seen on the underside.
The deep transverse fissure on the underside through which the portal vein, artery and bile duct enter and leave
The porta hepatis of the liver.
Wrapped in a fibrous capsule named after a seventeenth-century English physician, with a patch on its top that is not covered by peritoneum
Glisson's capsule, and the bare area of the liver.
Divided by Couinaud into eight functional segments, each with its own blood supply and drainage
The Couinaud segments of the liver.
The round ligament running in the free edge of the falciform ligament is the remnant of the foetal umbilical vein
The ligamentum teres of the liver.
Receives blood from two sources: a large vein from the gut and a smaller artery from the coeliac trunk
Liver — portal vein and hepatic artery, with about 75 per cent of blood from the portal vein.
Key ideas
- It is supplied by both the portal vein, carrying nutrient-rich blood from the intestines, and the hepatic artery, carrying oxygenated blood; blood leaves through the hepatic veins into the inferior vena cava.
- The organ can regenerate, and a partial resection or a living-donor transplant relies on the remaining tissue growing back.
Quick-fire facts
- •It weighs about 1.4 to 1.6 kg in an adult, about 2 per cent of body weight.
- •The skin is the largest organ overall; the liver is the largest internal organ and the largest gland.
- •The right lobe is much larger than the left; the caudate lobe lies between the inferior vena cava and the ligamentum venosum, and the quadrate lobe between the gallbladder and the ligamentum teres.
- •The ligamentum teres is the remains of the umbilical vein; the ligamentum venosum is the remains of the ductus venosus of the foetus.
- •The lesser omentum (hepatogastric and hepatoduodenal ligaments) attaches it to the stomach and duodenum, and its free edge carries the portal triad.
- •The Pringle manoeuvre is clamping the free edge of the lesser omentum to control bleeding from the liver.
- •Its upper limit lies at about the 5th intercostal space on the right, and its lower border runs along the costal margin, so the edge is normally not palpable in an adult.
- •Couinaud's classification (1957) divides it into 8 functional segments used in liver surgery.
- •The Riedel lobe is a tongue-like downward extension of the right lobe seen in some people.
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