Location & Position

Exact Location in Abdomen

  • Region: Right hypochondrium and epigastrium of abdomen
  • Position: Mainly in the upper right quadrant, extending into upper left quadrant
  • Vertical extent: From 5th intercostal space to right costal margin
  • Protected by: Rib cage (ribs 7-11 on right side)
  • Inferior extent: Does not normally extend below costal margin (if it does, indicates hepatomegaly)

Relations to Nearby Structures

Superior Relations

  • Diaphragm: Separates liver from lungs and pleura
  • Right pleura and lung: Related to upper part of right lobe
  • Heart: Left lobe related to heart through diaphragm
  • Pericardium: Anterior part of left lobe

Inferior (Visceral) Relations

  • Stomach: Left lobe shows gastric impression
  • Duodenum: 1st and 2nd parts create duodenal impression
  • Right kidney: Posterior part shows renal impression
  • Right suprarenal gland: Small suprarenal impression
  • Hepatic flexure of colon: Colic impression
  • Gallbladder: Fossa for gallbladder on visceral surface

Anterior Relations

  • Diaphragm: Separates from anterior abdominal wall
  • Right costal cartilages: 7th, 8th, 9th
  • Xiphoid process: Left lobe related

Posterior Relations

  • Diaphragm: Separates from vertebral column
  • IVC: Groove on posterior surface
  • Esophagus: Esophageal groove
  • Right kidney and suprarenal: Direct contact

Peritoneal Attachments

Important: Liver is an intraperitoneal organ EXCEPT for the bare area

  • Falciform Ligament: Connects liver to anterior abdominal wall and diaphragm. Contains ligamentum teres (obliterated umbilical vein). Separates right and left lobes anatomically.
  • Coronary Ligament: Connects posterior surface of liver to diaphragm. Has anterior and posterior layers. Encloses the bare area (area without peritoneal covering).
  • Right Triangular Ligament: Where anterior and posterior layers of coronary ligament meet on right side. Small triangular fold.
  • Left Triangular Ligament: Connects left lobe to diaphragm. Longer than right triangular ligament.

Gross Anatomy of Liver

Physical Characteristics

Weight
1.2–1.5 kg
About 2% of body weight
Size
25–28 cm wide
15–18 cm anteroposterior
Shape
Wedge-shaped
Thick on right, thin on left
Color
Reddish-brown
Due to rich blood supply

Anterior (Diaphragmatic) Surface Features

  • Surface: Smooth, convex, follows the curvature of diaphragm
  • Falciform ligament: Divides anterior surface into right and left parts
  • Ligamentum teres: Visible in free edge of falciform ligament
  • Color: Uniform reddish-brown
  • Consistency: Firm but soft (becomes hard in cirrhosis)
  • Coverage: Covered by peritoneum except at attachment of falciform ligament

Visceral (Inferior) Surface Features

The visceral surface is directed downwards, backwards, and to the left. It shows multiple impressions and important structures:

H-Shaped Fissures

  • Vertical right limb: Fossa for gallbladder (anteriorly) + Groove for IVC (posteriorly)
  • Vertical left limb: Fissure for ligamentum teres (anteriorly) + Fissure for ligamentum venosum (posteriorly)
  • Horizontal crossbar: Porta hepatis

Porta Hepatis

  • Central horizontal fissure
  • Gateway of liver (Latin: "gate of liver")
  • Entry and exit point for major vessels
  • About 5 cm long

Gallbladder Fossa

  • Located on right side of H
  • Houses the gallbladder
  • About 7–10 cm long
  • Separates quadrate lobe from right lobe

IVC Groove

  • Posterior continuation of gallbladder fossa
  • Deep groove for inferior vena cava
  • Hepatic veins drain directly into IVC here

Liver Impressions (Important for Exams)

1. Gastric Impression

Location: Left lobe, visceral surface

Caused by: Stomach (anterior surface and lesser curvature)

2. Duodenal Impression

Location: Right lobe, near porta hepatis

Caused by: First part of duodenum

3. Colic Impression

Location: Right lobe, lower visceral surface

Caused by: Right colic flexure (hepatic flexure)

4. Renal Impression

Location: Right lobe, posterior visceral surface

Caused by: Right kidney

5. Suprarenal Impression

Location: Near IVC groove, above renal impression

Caused by: Right suprarenal gland

6. Esophageal Impression

Location: Posterior surface of left lobe

Caused by: Lower end of esophagus

Lobes of Liver

Anatomical vs Physiological Lobes

Anatomical Division (Traditional)

Based on external surface features:

  • Divided by falciform ligament
  • 4 lobes: Right, Left, Quadrate, Caudate
  • Used in gross anatomy descriptions

Physiological/Functional Division

Based on blood supply and bile drainage:

  • Divided by Cantlie's line
  • 2 main functional lobes + 8 segments
  • Used in surgery and radiology
  • Quadrate and caudate lobes belong to LEFT functional lobe

Why this matters: During liver surgery, surgeons use functional division because each segment has its own blood supply and bile drainage. You can remove one segment without affecting others!

1. Right Lobe

Largest Lobe

Basic Features

  • About 6 times larger than left lobe
  • Occupies right hypochondrium
  • Separated from left lobe by falciform ligament (anteriorly)

Important Features

  • Contains gallbladder fossa on visceral surface
  • Shows renal, suprarenal, duodenal, colic impressions
  • Bare area located on posterior part

Right lobe is more commonly affected by liver diseases. Liver biopsy is often taken from right lobe.

2. Left Lobe

Smaller Lobe

Basic Features

  • Smaller and thinner than right lobe
  • Extends into left hypochondrium and epigastrium
  • Left triangular ligament attaches here

Important Features

  • Shows prominent gastric impression on visceral surface
  • Related to stomach, esophagus, and heart
  • Fissure for ligamentum teres on visceral surface

In functional division, quadrate and caudate lobes are part of left functional lobe.

3. Quadrate Lobe

Small, Inferior

Boundaries (Very Important for Exams)

  • Anteriorly: Inferior border of liver
  • Posteriorly: Porta hepatis
  • Right side: Fossa for gallbladder
  • Left side: Fissure for ligamentum teres

Important: Anatomically looks like right lobe BUT functionally belongs to LEFT lobe — receives blood from left hepatic artery, drains bile into left hepatic duct.

Related to gallbladder. Cholecystitis can affect this lobe.

4. Caudate Lobe

Posterior, Small

Boundaries

  • Anteriorly: Porta hepatis
  • Posteriorly: IVC
  • Right side: Groove for IVC
  • Left side: Fissure for ligamentum venosum

Unique features: Independent blood supply directly from portal vein; drains directly into IVC; can hypertrophy in cirrhosis when other lobes atrophy.

In cirrhosis, caudate lobe enlarges — "caudate lobe hypertrophy" is an important radiological sign!

Quick Summary: Anatomical Lobes

Lobe Size Key Features Functional Classification
Right Lobe Largest Gallbladder fossa, multiple impressions Right functional lobe
Left Lobe Smaller Gastric impression Left functional lobe
Quadrate Lobe Small Bounded by gallbladder and lig. teres LEFT functional lobe
Caudate Lobe Small Between IVC and lig. venosum LEFT functional lobe

Segmental Anatomy (Couinaud Segments)

Why Learn Liver Segments?

Surgical Planning

Remove diseased segments without affecting healthy ones.

Radiology

Tumor locations described using segment numbers in CT/MRI.

Interventional

Precise targeting for biopsies and ablations.

Clinical Communication

Universal language for doctors worldwide.

I

Segment I — Caudate Lobe

Location: Posterior surface of liver, between IVC and fissure for ligamentum venosum

Unique: Only segment on posterior surface; independent vascular supply; drains directly into IVC (not through hepatic veins)

Clinical: Spared in Budd-Chiari syndrome. Hypertrophies in cirrhosis.

LEFT LOBE SEGMENTS (II, III, IVa, IVb)

II

Segment II — Left Lateral Superior

Location: Upper part of left lateral sector

Related to heart and left dome of diaphragm. Left triangular ligament attaches here.

Supply: Left lateral portal vein + left hepatic artery branches

III

Segment III — Left Lateral Inferior

Location: Lower part of left lateral sector

Related to stomach (gastric impression). Forms left margin of liver.

Memory: Segments II + III together = Left lateral sector

IVa

Segment IVa — Left Medial Superior

Location: Upper part of left medial sector, superior to porta hepatis

Between falciform ligament and fissure for ligamentum venosum. Related to heart through diaphragm.

IVb

Segment IVb — Left Medial Inferior (Quadrate Lobe)

Location: Lower part of left medial sector = anatomical Quadrate lobe

Between gallbladder fossa (right) and ligamentum teres (left), anterior to porta hepatis.

Relations: Related to gallbladder and pylorus of stomach

RIGHT LOBE SEGMENTS (V, VI, VII, VIII)

V

Segment V — Right Anterior Inferior

Location: Lower part of right anterior sector, right side of gallbladder

Related to gallbladder, hepatic flexure of colon, right kidney.

Clinical: Common site for liver tumors; adjacent to gallbladder

VI

Segment VI — Right Posterior Inferior

Location: Lower part of right posterior sector

Related to right kidney (renal impression) and hepatic flexure of colon.

Memory: "Six sits on kidney"

VII

Segment VII — Right Posterior Superior

Location: Upper part of right posterior sector

Related to right dome of diaphragm and bare area of liver.

Clinical: Difficult to access surgically due to posterior position

VIII

Segment VIII — Right Anterior Superior

Location: Upper part of right anterior sector, forms upper anterior surface

Related to right dome of diaphragm and right lung.

Memory: "Eight is great" — largest of right anterior segments

Segments Summary Table

SegmentNameLocationMemory Trick
ICaudatePosterior"I am behind everyone"
IILeft lateral superiorUpper left lateral"Two is on top left"
IIILeft lateral inferiorLower left lateral"Three is below two"
IVaLeft medial superiorUpper left medial"Four-A is above porta"
IVbLeft medial inferior (Quadrate)Lower left medial"Four-B is below = quadrate"
VRight anterior inferiorLower right anterior"Five is near gallbladder"
VIRight posterior inferiorLower right posterior"Six sits on kidney"
VIIRight posterior superiorUpper right posterior"Seven is in heaven (high)"
VIIIRight anterior superiorUpper right anterior"Eight is great (large)"

Memory Techniques for Segments

Trick 1: Portal Triad per Segment

Each segment gets its own: Portal Vein branch + Hepatic Artery branch + Bile Duct (trifecta = independent unit).

Trick 2: Clock-face Method

  • Segment I is behind (cannot see)
  • Left side (9–12 o'clock): II, III, IV
  • Right anterior: VIII (top), V (bottom)
  • Right posterior: VII (top), VI (bottom)

Trick 3: Left-to-Right Counting

  • II–III (left lateral) → IV (left medial)
  • V–VIII (right lobe, counterclockwise)
  • I is special (posterior only)

Liver Surfaces & Borders

1. Diaphragmatic Surface

Description

  • Smooth, convex (dome-shaped)
  • Directed upward, forward, and to the right
  • Completely covered by peritoneum (except falciform ligament attachment)

Clinical

  • Liver dullness on percussion: 5th ICS to costal margin
  • Reduced dullness = pneumoperitoneum
  • Can be injured in lower chest trauma
  • Subphrenic abscess can form here

2. Visceral (Inferior) Surface

H-Shaped Fissures (Key Feature)

Right Vertical Limb
  • Anterior: Fossa for gallbladder
  • Posterior: Groove for IVC
Left Vertical Limb
  • Anterior: Fissure for ligamentum teres
  • Posterior: Fissure for ligamentum venosum
Horizontal Crossbar
  • Porta hepatis — about 5 cm long
  • Entry/exit for vessels, ducts, nerves

Areas NOT Covered by Peritoneum

  1. Porta hepatis
  2. Fossa for gallbladder
  3. Groove for IVC
  4. Bare area

3. Posterior Surface & Bare Area

Bare Area Boundaries

  • Anterior: Anterior layer of coronary ligament
  • Posterior: Posterior layer of coronary ligament
  • Right: Right triangular ligament
  • Left: IVC and caudate lobe

Clinical Importance

  • Only area without peritoneal covering
  • Direct pathway for spread of infections to/from diaphragm
  • Site where hepatic veins leave liver to enter IVC
  • Right kidney and suprarenal gland in direct contact

Inferior Border

Characteristics

  • Sharp, thin, well-defined edge
  • Oblique direction: 9th right to 8th left costal cartilage
  • Normal position: Does NOT extend below costal margin

Clinical Significance

Hepatomegaly: Inferior border extends BELOW costal margin. Measured in finger breadths. Sharp edge becomes rounded in cirrhosis.

Superior Border

Characteristics

  • Poorly defined, thick, rounded
  • Cannot be palpated (unlike inferior border)
  • Right: 5th intercostal space in mid-clavicular line
  • Left: 5th rib in mid-clavicular line

Normal liver span: 10–12 cm in mid-clavicular line. Reduced span suggests cirrhosis or atrophy.

Liver Ligaments

Understanding Liver Ligaments

Important Concept: Liver "ligaments" are NOT true ligaments. They are double-layered folds of peritoneum connecting liver to: diaphragm, anterior abdominal wall, or stomach (lesser omentum). Liver is mainly supported by intra-abdominal pressure and surrounding organs.

1. Falciform Ligament

Most Prominent

Description

  • Sickle-shaped double peritoneum (Latin "falx" = sickle)
  • Sagittal position (vertical, anterior-posterior)
  • Separates right and left anatomical lobes

Contents (Free Lower Border)

  • Ligamentum teres hepatis — obliterated left umbilical vein
  • Paraumbilical veins — connect portal to systemic system

Clinical Importance

  • Portal hypertension: Paraumbilical veins dilate → Caput medusae
  • Important surgical landmark

2. Ligamentum Teres

Fetal Remnant

Nature

  • Obliterated left umbilical vein from fetal life
  • Runs in FREE LOWER EDGE of falciform ligament
  • From umbilicus to left portal vein (~15–20 cm)

Fetal Function

  • In fetus = Left umbilical vein
  • Carried oxygenated blood from placenta to fetus
  • After birth: obliterates → becomes ligamentum teres

Clinical

  • Portal hypertension → paraumbilical veins reopen → Caput medusae

Memory: "Round ligament = Remnant of umbilical vein" (R-R-U)

3. Coronary Ligaments

Enclose Bare Area

Two Layers

Anterior Layer (Upper)
  • Reflected from diaphragmatic surface
  • Forms upper boundary of bare area
  • Continuous with falciform ligament
Posterior Layer (Lower)
  • Reflected from posterior surface
  • Forms lower boundary of bare area
  • Continues as lesser omentum

Clinical

  • Subphrenic abscess can develop here
  • Hepatic veins pass through bare area to IVC
  • Important during hepatectomy

4 & 5. Triangular Ligaments

Lateral Ends
FeatureLeftRight
LengthLongerShorter (small)
Lobe attachedLeft lobeRight lobe
FormationCoronary layers meet (left side)Coronary layers meet (right side)
Surgical useDivided in left hepatectomyDivided in right hepatectomy

Memory: "Left is Longer, Right is Runt"

6. Lesser Omentum

Portal Triad Inside

Two Parts

Hepatogastric Ligament
  • Liver → lesser curvature of stomach
  • Broad, thin membrane
  • Contains: right/left gastric vessels, lymph nodes, vagal branches
Hepatoduodenal Ligament
  • Porta hepatis → 1st part of duodenum
  • Thick, free right border
  • Contains Portal Triad (DAV)

Portal Triad — "DAV" (Right to Left):

  • Duct (CBD) — rightmost
  • Artery (Hepatic artery proper) — middle left
  • Vein (Portal vein) — posterior, largest

Pringle Maneuver: Clamp hepatoduodenal ligament to stop liver bleeding in emergency surgery (controls portal vein + hepatic artery). Safe for 20–30 min.

Ligaments Quick Summary

LigamentConnectsKey FeatureClinical Point
FalciformLiver → Ant. abd. wall & diaphragmContains ligamentum teres in free edgeCaput medusae in portal hypertension
Lig. TeresUmbilicus → Left portal veinObliterated umbilical veinReopens in portal hypertension
CoronaryLiver → Diaphragm (posterior)Encloses bare areaHepatic veins pass through
Right TriangularRight lobe → DiaphragmSmall, shortDivided in right hepatectomy
Left TriangularLeft lobe → DiaphragmLonger than rightDivided in left hepatectomy
Lesser OmentumLiver → Stomach & duodenumPortal triad in free edgePringle maneuver

Blood Supply of Liver

Dual Blood Supply — Key Concept

Portal Vein (70–75%)

  • Nutrient-rich blood from GI tract and spleen
  • Less oxygenated
  • Formed by SMV + splenic vein (behind neck of pancreas)
  • Enters liver at porta hepatis
  • Divides into right and left branches

Hepatic Artery (25–30%)

  • Oxygenated blood from aorta
  • Celiac trunk → Common hepatic artery → Proper hepatic artery
  • Divides into right and left hepatic arteries
  • Right hepatic artery crosses behind CBD (important surgical point)
  • Cystic artery arises from right hepatic artery

Venous Drainage

  • Hepatic veins: 3 main veins (right, middle, left) drain into IVC
  • Right hepatic vein: Drains segments V, VI, VII, VIII
  • Middle hepatic vein: Drains segments IV, V, VIII (often joins left)
  • Left hepatic vein: Drains segments II, III, IV
  • Caudate lobe: Direct drainage into IVC via separate small veins
  • IVC: Receives hepatic veins just below diaphragm (at T8 level)

Portal Hypertension — Portosystemic Anastomoses

When portal pressure increases (cirrhosis), blood bypasses liver via porto-systemic connections:

  • Esophageal varices: Left gastric vein → esophageal veins → azygos (risk of rupture = life-threatening bleed)
  • Caput medusae: Paraumbilical veins → superficial abdominal veins around umbilicus
  • Hemorrhoids: Superior rectal vein → middle/inferior rectal veins
  • Retroperitoneal anastomoses: Portal branches → retroperitoneal veins

Clinical Anatomy

Hepatomegaly

Enlarged liver palpable below costal margin. Causes: hepatitis, cirrhosis, malignancy, heart failure, metabolic disorders.

Jaundice

Yellow discoloration due to bilirubin accumulation. Pre-hepatic (hemolysis), hepatic (hepatitis/cirrhosis), or post-hepatic (bile duct obstruction).

Cirrhosis

Fibrosis replaces normal liver tissue. Causes: alcohol, hepatitis B/C, NAFLD. Leads to portal hypertension.

Liver Biopsy

Usually from right lobe via intercostal approach. Patient holds breath to avoid pneumothorax. Risk: bleeding from hepatic vessels.

Budd-Chiari Syndrome

Hepatic vein thrombosis. Caudate lobe (Segment I) is SPARED as it drains directly into IVC. Characteristic caudate lobe hypertrophy.

Liver Trauma

Right lobe more commonly injured (larger, less protected). Bare area allows retroperitoneal hematoma formation. IVC injury = massive hemorrhage.

Subphrenic Abscess

Pus between liver and diaphragm. Via bare area or after abdominal surgery. Right subphrenic most common. Requires drainage.

Liver Transplantation

Anastomose: IVC, portal vein, hepatic artery, bile duct. Living donor: segments II-III (left lateral) for pediatric; right lobe for adult recipients.

NEET / Exam High-Yield Points

Must-Know Facts for NEET

Lobes & Functional Division

  • Quadrate lobe = functionally LEFT (not right)
  • Caudate lobe = functionally LEFT (not right)
  • Cantlie's line divides functional lobes
  • Falciform ligament divides anatomical lobes

Ligamentum Teres & Venosum

  • Lig. teres = obliterated LEFT umbilical vein
  • Lig. venosum = obliterated ductus venosus
  • Both are fetal remnants
  • Lig. teres is in free edge of falciform lig.

Portal Triad — DAV Rule

  • Duct (CBD) = right side
  • Artery (hepatic) = left side
  • Vein (portal) = posterior
  • Pringle maneuver = clamp free right edge of lesser omentum

Caudate Lobe Special Points

  • Spared in Budd-Chiari syndrome
  • Hypertrophies in cirrhosis
  • Independent blood supply from portal vein
  • Drains DIRECTLY into IVC

Porta Hepatis Contents

  • Right portal vein (larger) + Left portal vein
  • Hepatic artery (right + left branches)
  • Right + Left hepatic ducts
  • Lymph nodes and lymphatics

Blood Supply Numbers

  • Portal vein = 70–75% of blood supply
  • Hepatic artery = 25–30% of blood supply
  • But artery provides ~50% of oxygen
  • Dual blood supply = unique to liver

Common NEET Questions

QuestionAnswer
Largest lobe of liverRight lobe
Quadrate lobe belongs to which functional lobe?LEFT functional lobe
Caudate lobe is spared in which condition?Budd-Chiari syndrome
What is ligamentum teres?Obliterated left umbilical vein
What is ligamentum venosum?Obliterated ductus venosus
Contents of free edge of lesser omentum (DAV)?Duct (CBD), Artery (hepatic), Vein (portal)
Number of functional segments of liver8 (Couinaud classification)
What is Pringle maneuver?Clamping hepatoduodenal ligament to stop liver bleeding
Where do hepatic veins drain?Into IVC just below diaphragm
Bare area of liver — what is unique?No peritoneal covering; directly attached to diaphragm
Caput medusae occurs due to?Paraumbilical vein dilatation in portal hypertension
Which ligament separates anatomical lobes?Falciform ligament