Quick Jump to Sections

Location Gross Anatomy Lobes Segments Surfaces Ligaments Porta Hepatis Blood Supply Biliary System Histology Functions Clinical
Section A

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 is related to heart through diaphragm
  • Pericardium: Anterior part of left lobe

Inferior (Visceral) Relations

  • Stomach: Left lobe shows gastric impression
  • Duodenum: First and second 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
  • Esophagus: Posterior part of left lobe

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
  • Inferior vena cava (IVC): Groove on posterior surface
  • Esophagus: Esophageal groove
  • Aorta: Through diaphragm
  • 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
    • Separates right and left lobes (anatomically)
    • Contains ligamentum teres (obliterated umbilical vein)
    • Extends from bare area to umbilicus
  • Coronary Ligament:
    • Connects posterior surface of liver to diaphragm
    • Has anterior and posterior layers
    • Encloses the bare area (area without peritoneal covering)
    • Anterior layer: reflection of peritoneum from diaphragmatic surface
    • Posterior layer: reflection from posterior surface
  • Right Triangular Ligament:
    • Where anterior and posterior layers of coronary ligament meet on right side
    • Small triangular fold
  • Left Triangular Ligament:
    • Where anterior and posterior layers meet on left side
    • Connects left lobe to diaphragm
    • Longer than right triangular ligament
Section B

Gross Anatomy of Liver

Physical Characteristics

Weight
1.2-1.5 kg (Adult)
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
  • Upper border: Related to diaphragm, hence to heart and lungs

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

The visceral surface has characteristic 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)

Appearance: Shallow concave depression

2. Duodenal Impression

Location: Right lobe, near porta hepatis

Caused by: First part of duodenum

Appearance: Small shallow depression

3. Colic Impression

Location: Right lobe, lower part of visceral surface

Caused by: Right colic flexure (hepatic flexure)

Appearance: Variable depression

4. Renal Impression

Location: Right lobe, posterior part of visceral surface

Caused by: Right kidney

Appearance: Deep concave impression

5. Suprarenal Impression

Location: Near IVC groove, above renal impression

Caused by: Right suprarenal gland

Appearance: Small triangular depression

6. Esophageal Impression

Location: Posterior surface of left lobe

Caused by: Lower end of esophagus

Appearance: Small depression

Bare Area of Liver

Clinical Importance: The bare area is where liver is directly in contact with diaphragm without peritoneal covering. Infections can spread here.

  • Location: Posterior surface of right lobe
  • Shape: Triangular or quadrilateral area
  • Boundaries:
    • Anterior: Anterior layer of coronary ligament
    • Posterior: Posterior layer of coronary ligament
    • Right: Right triangular ligament
    • Left: IVC and caudate lobe
  • Relations: Directly attached to diaphragm (no peritoneum)
  • Significance:
    • Only area without peritoneal covering
    • Direct pathway for spread of infections to/from diaphragm
    • Site where hepatic veins leave liver to enter IVC
Section C

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 (imaginary line from IVC to gallbladder fossa)
  • 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

  • Size: Largest lobe, about 6 times larger than left lobe
  • Position: Occupies right hypochondrium
  • Boundaries:
    • Anteriorly: Separated from left lobe by falciform ligament
    • Posteriorly: Separated by fissure for ligamentum venosum and IVC groove
    • On visceral surface: Bounded by H-shaped fissures

Important Features

  • Contains gallbladder fossa on its visceral surface
  • Shows renal, suprarenal, duodenal, and colic impressions
  • Related to right kidney, right colic flexure, duodenum
  • Bare area located on posterior part

Clinical Note

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

2. Left Lobe

Smaller Lobe

Basic Features

  • Size: Smaller and thinner than right lobe
  • Position: Extends into left hypochondrium and epigastrium
  • Boundaries:
    • Right margin: Falciform ligament (anterior), fissure for ligamentum venosum (posterior)
    • Left margin: Left triangular ligament

Important Features

  • Shows prominent gastric impression on visceral surface
  • Related to stomach, esophagus, and heart
  • Attached to diaphragm by left triangular ligament
  • Fissure for ligamentum teres on its visceral surface

Remember

Left lobe receives blood mainly from left branches of hepatic artery and portal vein. In functional division, quadrate and caudate lobes are part of left functional lobe.

3. Quadrate Lobe

Small, Inferior

Basic Features

  • Location: Visceral surface only (cannot be seen from above)
  • Shape: Roughly quadrilateral (hence name "quadrate")
  • Position: Between right and left lobes, anterior to porta hepatis

Boundaries (Very Important for Exams)

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

Functional Anatomy

Important: Anatomically looks like part of right lobe, BUT functionally belongs to LEFT lobe because:

  • Receives blood from left hepatic artery
  • Drains bile into left hepatic duct
  • Supplied by left portal vein branches

Clinical Relevance

Quadrate lobe is related to gallbladder. Inflammation of gallbladder (cholecystitis) can affect this lobe.

4. Caudate Lobe

Posterior, Small

Basic Features

  • Location: Posterior surface of liver (cannot be seen from front)
  • Shape: Tail-like projection (Latin "cauda" = tail)
  • Position: Between IVC and fissure for ligamentum venosum

Boundaries

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

Parts of Caudate Lobe

  • Caudate process: Thin strip connecting caudate lobe to right lobe (runs to right, posterior to porta hepatis)
  • Papillary process: Small elevation on left side of caudate lobe

Unique Features

Special characteristics of caudate lobe:

  • Has independent blood supply directly from portal vein and hepatic artery
  • Drains directly into IVC (hepatic veins drain separately)
  • Like quadrate lobe, functionally belongs to LEFT lobe
  • Can undergo hypertrophy in cirrhosis when other lobes atrophy

Clinical Importance

In cirrhosis with portal hypertension, caudate lobe often enlarges because it has direct drainage to IVC, bypassing the obstructed hepatic veins. This is called "caudate lobe hypertrophy" - an important radiological sign!

Quick Summary: Anatomical Lobes

Lobe Size Location Key Features Functional Classification
Right Lobe Largest Right side, entire right hypochondrium Gallbladder fossa, multiple impressions Right functional lobe
Left Lobe Smaller Extends to left hypochondrium Gastric impression Left functional lobe
Quadrate Lobe Small Visceral surface, anterior to porta Bounded by gallbladder and lig. teres LEFT functional lobe
Caudate Lobe Small Posterior surface Between IVC and lig. venosum LEFT functional lobe
Section D

Segmental Anatomy (Couinaud Segments)

Why Learn Liver Segments?

Surgical Planning

Surgeons can remove diseased segments without affecting healthy ones. Each segment is an independent functional unit.

Radiology

Doctors describe tumor locations using segment numbers in CT scans and MRI reports.

Interventional Procedures

Precise targeting for biopsies, ablations, and localized treatments.

Clinical Communication

Universal language for doctors worldwide to discuss liver pathology.

The Couinaud Classification System

French surgeon Claude Couinaud (1957) divided liver into 8 functionally independent segments based on:

  • Portal vein branches: Each segment receives its own portal vein branch
  • Hepatic artery branches: Each segment has dedicated arterial supply
  • Bile duct drainage: Each segment drains through its own bile duct
  • Hepatic vein position: Segments are separated by hepatic veins

Key Concept: Each segment is a self-contained unit with its own blood supply and drainage - like separate mini-organs within the liver!

Understanding the 8 Segments

Segments are numbered I to VIII (Roman numerals). Think of liver divided by 3 imaginary planes:

  • Cantlie's line (vertical): Right plane, divides right from left lobe
  • Right hepatic vein (vertical): Divides right lobe into anterior and posterior sectors
  • Left hepatic vein (vertical): Divides left lobe into medial and lateral sectors
  • Horizontal plane: Through portal vein bifurcation, divides into superior and inferior segments
I

Segment I - Caudate Lobe

Location: Posterior surface of liver

Unique Features:

  • Only segment on posterior surface
  • Between IVC and fissure for ligamentum venosum
  • Has independent vascular supply directly from portal vein
  • Drains directly into IVC (not through hepatic veins)
  • Can be seen from behind, not from front

Clinical Note: Spared in Budd-Chiari syndrome (hepatic vein thrombosis) because of direct IVC drainage. Often hypertrophies in cirrhosis.

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

II

Segment II - Left Lateral Superior

Location: Upper part of left lateral sector

Position: Superior and posterior part of left lobe

Relations:

  • Related to heart and left dome of diaphragm
  • Left triangular ligament attaches here
  • Most superior and lateral part of left lobe

Blood Supply:

  • Left lateral portal vein branch
  • Left hepatic artery branch

Drainage: Left hepatic duct → Common hepatic duct

III

Segment III - Left Lateral Inferior

Location: Lower part of left lateral sector

Position: Inferior part of left lobe

Relations:

  • Related to stomach (gastric impression)
  • Forms left margin of liver
  • Extends to inferior border of liver

Blood Supply: Left lateral portal branches

Easy Memory: Segments II and III together = Left lateral sector (visible from front)

IVa

Segment IVa - Left Medial Superior

Location: Upper part of left medial sector

Position: Superior to porta hepatis, between falciform ligament and fissure for ligamentum venosum

Relations:

  • Related to heart through diaphragm
  • Anteriorly related to anterior abdominal wall

Blood Supply: Left medial portal vein branches

IVb

Segment IVb - Left Medial Inferior (Quadrate Lobe)

Location: Lower part of left medial sector

Position: Inferior to porta hepatis = Quadrate lobe

Boundaries:

  • Between gallbladder fossa (right) and ligamentum teres (left)
  • Anterior to porta hepatis
  • Reaches inferior margin of liver

Relations: Related to gallbladder, pylorus of stomach

Important: This is the anatomical quadrate lobe (Section C)

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

V

Segment V - Right Anterior Inferior

Location: Lower part of right anterior sector

Position: Inferior and anterior, right side of gallbladder

Relations:

  • Related to gallbladder (right side of gallbladder fossa)
  • Related to hepatic flexure of colon
  • Related to right kidney

Blood Supply: Right anterior portal vein branches

Clinical Note: Common site for liver tumors; adjacent to gallbladder

VI

Segment VI - Right Posterior Inferior

Location: Lower part of right posterior sector

Position: Posterior and inferior part of right lobe

Relations:

  • Related to right kidney (renal impression)
  • Related to hepatic flexure of colon
  • Most inferior and posterior on right side

Blood Supply: Right posterior portal branches

Easy Memory: "Six sits on kidney" - related to right kidney

VII

Segment VII - Right Posterior Superior

Location: Upper part of right posterior sector

Position: Posterior and superior, between right and middle hepatic veins

Relations:

  • Related to right dome of diaphragm
  • Related to bare area of liver
  • Most posterior and superior on right side

Blood Supply: Right posterior portal branches

Clinical Note: Difficult to access surgically due to posterior position

VIII

Segment VIII - Right Anterior Superior

Location: Upper part of right anterior sector

Position: Anterior and superior, between middle and right hepatic veins

Relations:

  • Related to right dome of diaphragm and right lung
  • Forms upper part of anterior surface
  • Most superior on right anterior side

Blood Supply: Right anterior portal branches

Easy Memory: "Eight is great" - largest of right anterior segments

Segments Summary Table

Segment Name Location Easy Memory Trick
I Caudate Posterior "I am behind everyone"
II Left lateral superior Upper left lateral "Two is on top left"
III Left lateral inferior Lower left lateral "Three is below two"
IVa Left medial superior Upper left medial "Four-A is above porta"
IVb Left medial inferior (Quadrate) Lower left medial "Four-B is below = quadrate"
V Right anterior inferior Lower right anterior "Five is near gallbladder"
VI Right posterior inferior Lower right posterior "Six sits on kidney"
VII Right posterior superior Upper right posterior "Seven is in heaven (high up)"
VIII Right anterior superior Upper right anterior "Eight is great (large)"

Portal Triads and Segments

Each segment receives its blood supply through a portal triad (तीन चीजों का समूह):

1. Portal Vein Branch

Brings nutrient-rich blood from intestines (70% of liver blood)

2. Hepatic Artery Branch

Brings oxygen-rich blood from aorta (30% of liver blood)

3. Bile Duct

Drains bile produced by hepatocytes in that segment

Why this matters in surgery: When removing a segment, surgeon ligates (ties off) all three structures in the portal triad for that segment. Other segments continue functioning normally!

Simplified Way to Remember Segments

🎯 Trick 1: Clock-face Method

Imagine looking at liver from front:

  • Segment I is behind (cannot see)
  • Left side (9-12 o'clock): II, III, IV
  • Right side (12-3 o'clock): VIII, V
  • Right side back (3-6 o'clock): VII, VI

🎯 Trick 2: "Odd on Top" for Right Lobe

In right lobe:

  • ODD numbers (VII, V) - Anterior sector
  • EVEN numbers (VIII, VI) - Posterior sector
  • Higher numbers (VIII, VII) - Superior
  • Lower numbers (V, VI) - Inferior

🎯 Trick 3: Left-to-Right Counting

Start from left, move right:

  • II-III (left lateral) → IV (left medial) → V-VIII (right lobe)
  • I is special (posterior only)
Section E

Liver Surfaces & Borders

Overview of Liver Surfaces

The liver has 5 surfaces/areas to study:

  • Diaphragmatic surface - Superior, anterior, and right lateral
  • Visceral surface - Inferior surface (postero-inferior)
  • Posterior surface - Includes bare area
  • Inferior border - Sharp margin
  • Superior border - Poorly defined

1. Diaphragmatic Surface

Description

  • Shape: Smooth, convex (dome-shaped)
  • Position: Directed upward, forward, and to the right
  • Coverage: Completely covered by peritoneum (except where falciform ligament attaches)
  • Relations: Separated from diaphragm by peritoneal cavity

Subdivisions

  • Superior surface (facies superior): Related to central tendon of diaphragm, heart above
  • Anterior surface (facies anterior): Related to right costal cartilages and diaphragm
  • Right surface (facies dextra): Related to right dome of diaphragm, right lung and pleura

Important Features

  • Falciform ligament: Attaches to anterior part, divides into right and left portions
  • Cardiac impression: Central depression where heart rests on liver through diaphragm
  • Surface markings:
    • Upper border: 5th intercostal space (right), 5th rib (left)
    • Lower border: Right costal margin (normally should not extend below)

Clinical Relations

Clinical Importance:

  • Liver dullness on percussion: Normally extends from 5th intercostal space to costal margin
  • Reduced dullness suggests pneumoperitoneum (air in abdomen)
  • Diaphragmatic surface can be injured in lower chest trauma
  • Subphrenic abscess can develop between liver and diaphragm

2. Visceral (Inferior) Surface

Description

  • Shape: Irregular, concave, shows multiple impressions
  • Position: Directed downward, backward, and to the left
  • Coverage: Covered by peritoneum except at:
    • Porta hepatis
    • Gallbladder fossa
    • Bare area (posterior part)
  • Direction: Postero-inferior and left

H-Shaped Fissures (Most Important)

The characteristic H-shaped pattern divides visceral surface:

Right Vertical Limb
  • Anterior: Fossa for gallbladder (about 7-10 cm)
  • Posterior: Groove for IVC (about 3 cm wide)
  • These two structures are connected and form right boundary of quadrate and caudate lobes
Left Vertical Limb
  • Anterior: Fissure for ligamentum teres (contains obliterated umbilical vein)
  • Posterior: Fissure for ligamentum venosum (contains obliterated ductus venosus)
  • Forms left boundary of quadrate and caudate lobes
Horizontal Crossbar
  • Porta hepatis - the gateway of liver
  • About 5 cm long transverse fissure
  • Connects right and left vertical limbs
  • Site of entry/exit for vessels, ducts, nerves

Impressions on Visceral Surface

Various organs create impressions (already detailed in Section B):

  • Left lobe: Gastric impression, esophageal impression
  • Right lobe: Renal, suprarenal, duodenal, colic impressions
  • Quadrate lobe: Related to pylorus

Areas Not Covered by Peritoneum

  1. Porta hepatis: Allows passage of structures
  2. Fossa for gallbladder: Gallbladder attached here
  3. Groove for IVC: IVC embedded here
  4. Bare area: Direct contact with diaphragm

3. Posterior Surface

Description

  • Shape: Broad and rounded on right, narrow on left
  • Position: Faces backward
  • Coverage: Mostly devoid of peritoneum (bare area)
  • Relations: Directly attached to diaphragm in bare area

Main Features

  • Bare area:
    • Large triangular/quadrilateral area
    • Direct contact with diaphragm (no peritoneum)
    • Bounded by coronary ligaments
    • Site where hepatic veins enter IVC
  • Groove for IVC:
    • Deep vertical groove on right side of bare area
    • About 3 cm wide
    • IVC partially embedded in liver tissue
    • Right, middle, and left hepatic veins drain into IVC here
  • Caudate lobe:
    • Visible on posterior surface
    • Between IVC and ligamentum venosum
  • Fissure for ligamentum venosum:
    • Deep fissure on left side
    • Contains obliterated ductus venosus
    • Separates caudate lobe from left lobe

Relations of Posterior Surface

  • Through diaphragm:
    • Aorta (at T12 level)
    • Vertebral bodies (T10-T12)
    • Right crus of diaphragm
  • Direct contact (no diaphragm):
    • Right kidney and suprarenal gland
    • IVC
  • Upper left part: Esophagus (esophageal impression on caudate lobe)

4. Inferior Border (Margo Inferior)

Characteristics

  • Shape: Sharp, thin, well-defined edge
  • Direction: Oblique - from 9th right costal cartilage to 8th left costal cartilage
  • Normal position: Should NOT extend below costal margin
  • Palpation: Can be felt when patient takes deep breath (in thin individuals)

Important Landmarks

  • Notch for fundus of gallbladder: Where gallbladder touches inferior border (at tip of 9th costal cartilage)
  • Right end: At right mid-clavicular line
  • Left end: Extends to left side, reaches 8th costal cartilage

Clinical Significance

Hepatomegaly (enlarged liver):

  • Inferior border extends BELOW costal margin
  • Measured in "finger breadths below costal margin"
  • Can be palpated during clinical examination
  • Sharp edge becomes rounded in cirrhosis
  • May extend to umbilicus or even pelvis in massive enlargement

Surface Marking

  • Right: Right costal margin in mid-clavicular line (9th costal cartilage)
  • Crosses midline below xiphisternum
  • Left: 8th left costal cartilage
  • Inferior border crosses transpyloric plane at midline

5. Superior Border

Characteristics

  • Definition: Poorly defined, thick, rounded
  • Shape: Corresponds to diaphragmatic convexity
  • Cannot be palpated (unlike inferior border)

Position

  • Right side: 5th intercostal space in mid-clavicular line
  • Midline: Xiphisternum level
  • Left side: 5th rib in mid-clavicular line (slightly lower than right)

Relations

  • Separated from thoracic cavity by diaphragm
  • Right lung and pleura above (right side)
  • Heart above (central and left)
  • Protected by rib cage

Clinical Note

Percussion of superior border helps determine liver span. Normal liver span is 10-12 cm in mid-clavicular line. Reduced span suggests liver cirrhosis or atrophy.

Quick Surface Summary

Surface/Border Shape Direction Coverage Key Features
Diaphragmatic Smooth, convex Upward, forward, right Peritoneum (except falciform attachment) Related to diaphragm, heart, lungs
Visceral Irregular, concave Downward, backward, left Peritoneum (except porta, GB fossa, IVC) H-shaped fissures, impressions
Posterior Broad (right), narrow (left) Backward Mostly no peritoneum (bare area) Bare area, IVC groove, caudate lobe
Inferior Border Sharp, thin Oblique (right to left) Peritoneum Normally at costal margin, palpable
Superior Border Rounded, thick Follows diaphragm curve Peritoneum Not palpable, at 5th ICS/rib level
Section F

Liver Ligaments

Understanding Liver Ligaments

Important Concept: Liver "ligaments" are NOT true ligaments (like knee ligaments). They are double-layered folds of peritoneum connecting liver to:

  • Diaphragm
  • Anterior abdominal wall
  • Stomach (lesser omentum)

Function: Help hold liver in position, but liver is mainly supported by intra-abdominal pressure and surrounding organs

1. Falciform Ligament

Most Prominent

Description

  • Shape: Sickle-shaped (Latin "falx" = sickle)
  • Structure: Double layer of peritoneum
  • Position: Sagittal plane (vertical, anterior-posterior)
  • Visible: Can be seen easily from anterior view

Attachments

  • Superior: Diaphragm and anterior abdominal wall (from umbilicus to diaphragm)
  • Inferior: Extends from umbilicus to liver's anterior surface
  • Posterior: Reaches anterior layer of coronary ligament at bare area
  • On liver: Separates right and left anatomical lobes

Contents

  • Ligamentum teres hepatis (round ligament)
    • Runs in FREE LOWER BORDER of falciform ligament
    • Obliterated left umbilical vein
    • Extends from umbilicus to left portal vein
  • Paraumbilical veins: Small veins connecting portal system to systemic veins

Clinical Importance

  • Portal hypertension: Paraumbilical veins dilate → Caput medusae (dilated veins around umbilicus)
  • Surgery: Important landmark during abdominal operations
  • Liver biopsy: Helps identify right vs left lobe

Anatomical Relations

  • Divides liver into right lobe (larger) and left lobe (smaller) anatomically
  • This division is NOT same as functional division
  • Attached along anterior-superior surface of liver

2. Ligamentum Teres (Round Ligament)

Fetal Remnant

Description

  • Shape: Round fibrous cord
  • Nature: Obliterated left umbilical vein from fetal life
  • Position: Lies in free edge of falciform ligament
  • Length: From umbilicus to liver, about 15-20 cm

Course

  • Starts: Umbilicus
  • Travels: In free lower edge of falciform ligament (ascending)
  • Reaches: Visceral surface of liver at anterior notch
  • Ends: Continues in fissure for ligamentum teres to reach left portal vein

Fetal Function (Before Birth)

  • In fetus = Left umbilical vein
  • Carried oxygenated blood from placenta to fetus
  • Blood went through liver → ductus venosus → IVC → heart
  • After birth: Vein obliterates (closes) → becomes ligamentum teres

Adult Function & Clinical Importance

  • Normal adult: No function, just fibrous remnant
  • Contains: Paraumbilical veins (small veins connecting portal and systemic systems)
  • Portal hypertension:
    • Paraumbilical veins reopen and dilate
    • Create porto-systemic shunt around umbilicus
    • Visible as "Caput medusae" (medusa head pattern of veins)
  • Surgical landmark: Helps identify left portal vein

Related Structures

  • Fissure for ligamentum teres: Groove on visceral surface where it runs
  • Left portal vein: Where ligamentum teres ends
  • Falciform ligament: Surrounds it in its free edge

Easy Memory: "Round ligament = Remnant of Umbilical vein" (R-R-U pattern)

3. Coronary Ligaments

Enclose Bare Area

Description

  • Structure: Two layers of peritoneum (anterior and posterior)
  • Position: On posterior surface of liver
  • Function: Connect posterior liver to diaphragm
  • Important: Enclose the bare area between the two layers

Two Layers

Anterior Layer (Upper)
  • Peritoneum reflected from diaphragmatic surface
  • Where anterior surface becomes posterior
  • Continuous with falciform ligament anteriorly
  • Forms upper boundary of bare area
Posterior Layer (Lower)
  • Peritoneum reflected from posterior/inferior surface
  • Continues as lesser omentum (hepatogastric ligament)
  • Forms lower boundary of bare area
  • More extensive than anterior layer

Area Enclosed

  • Between anterior and posterior layers = BARE AREA
  • Bare area has NO peritoneal covering
  • Direct attachment of liver to diaphragm here
  • Triangular/quadrilateral shape

Lateral Endings

  • On RIGHT SIDE: Two layers meet → Right triangular ligament
  • On LEFT SIDE: Two layers meet → Left triangular ligament
  • Coronary ligaments are continuous with triangular ligaments

Clinical Importance

  • Subphrenic abscess: Pus can collect between liver and diaphragm
  • Hepatic veins: Pass through bare area to enter IVC
  • Spread of infection: Bare area allows direct spread between liver and diaphragm
  • Surgery: Important during hepatectomy (liver removal surgery)

Boundaries of Bare Area (Formed by Coronary Ligaments)

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

4. Right Triangular Ligament

Small, Right Side

Description

  • Shape: Small triangular fold
  • Formation: Where anterior and posterior layers of coronary ligament meet on RIGHT side
  • Size: Small, short
  • Position: Right lateral end of bare area

Attachments

  • From: Right lobe of liver (right lateral part)
  • To: Right dome of diaphragm
  • Relations: Marks right lateral limit of bare area

Clinical Relevance

  • Must be divided during right hepatectomy (removal of right liver lobe)
  • Small size makes it easy to divide surgically
  • Helps mobilize right lobe during surgery

5. Left Triangular Ligament

Longer, Left Side

Description

  • Shape: Triangular fold
  • Formation: Where anterior and posterior layers of coronary ligament meet on LEFT side
  • Size: Longer than right triangular ligament
  • Position: Between left lobe and diaphragm

Attachments

  • From: Superior surface of left lobe
  • To: Diaphragm (left dome)
  • Relation: Lies to left of falciform ligament

Comparison with Right Triangular Ligament

Feature Left Right
Length Longer Shorter
Lobe attached Left lobe Right lobe
Surgical access Easier to mobilize Simpler to divide

Clinical Relevance

  • Division needed for left hepatectomy
  • Important for mobilizing left lobe
  • Longer extent makes mobilization easier

6. Lesser Omentum

Double-Layered

Description

  • Structure: Double layer of peritoneum
  • Position: Extends from liver to stomach and duodenum
  • Shape: Gastrohepatic part is wide, hepatoduodenal part is narrow
  • Function: Connects liver to upper digestive tract

Two Parts

A) Hepatogastric Ligament
  • From: Fissure for ligamentum venosum and porta hepatis on liver
  • To: Lesser curvature of stomach
  • Shape: Broad, thin membrane
  • Contents:
    • Right and left gastric vessels
    • Lymph nodes
    • Vagal nerve branches
  • Clinical: Divided during gastrectomy surgeries
B) Hepatoduodenal Ligament
  • From: Porta hepatis
  • To: First part of duodenum (superior part)
  • Shape: Thick, tubular, free right border
  • Forms: Anterior boundary of epiploic foramen (of Winslow)
  • Contents (Portal Triad):
    • Portal vein (posterior)
    • Hepatic artery proper (anterior left)
    • Common bile duct (anterior right)
    • Lymph nodes, lymphatics, nerves

Contents of Free Right Border (Portal Triad)

Arrangement in FREE EDGE (from anterior to posterior):

  • Right side: Common bile duct (CBD)
  • Left side: Hepatic artery proper
  • Posterior: Portal vein (largest)

Memory trick: "DAV" from right to left - Duct, Artery, Vein

Clinical Importance - Pringle Maneuver

Emergency Technique:

  • During liver surgery or trauma, if severe bleeding occurs
  • Surgeon clamps the hepatoduodenal ligament (free right border)
  • This stops blood flow: portal vein + hepatic artery
  • Controls bleeding temporarily (max 20-30 minutes safely)
  • Allows surgeon to identify bleeding source

Epiploic Foramen (Foramen of Winslow)

  • Location: Behind free right edge of lesser omentum
  • Boundaries:
    • Anterior: Hepatoduodenal ligament (portal triad)
    • Posterior: IVC
    • Superior: Caudate lobe of liver
    • Inferior: First part of duodenum
  • Significance: Communication between greater and lesser sacs
  • Clinical: Allows spread of infections between sacs

Ligaments Quick Summary

Ligament Connects Key Feature Clinical Point
Falciform Liver ↔ Ant. abd. wall & diaphragm Contains ligamentum teres in free edge Caput medusae in portal hypertension
Ligamentum Teres Umbilicus ↔ Left portal vein Obliterated umbilical vein Reopens in portal hypertension
Coronary Liver ↔ Diaphragm (posterior) Encloses bare area Hepatic veins pass through
Right Triangular Right lobe ↔ Diaphragm Small, short Divided in right hepatectomy
Left Triangular Left lobe ↔ Diaphragm Longer than right Divided in left hepatectomy
Lesser Omentum Liver ↔ Stomach & duodenum Contains portal triad in free edge Pringle maneuver - clamp to stop bleeding

Memory Techniques for Ligaments

🎯 For Lesser Omentum Contents (Portal Triad)

"DAV" arrangement (Right to Left):

  • Duct (Common bile duct) - rightmost
  • Artery (Hepatic artery proper) - middle left
  • Vein (Portal vein) - posterior, largest

🎯 For Fetal Remnants

Two fetal remnants in liver:

  • Ligamentum teres = Umbilical vein (brought blood FROM placenta)
  • Ligamentum venosum = Ductus venosus (bypassed liver TO reach heart)

🎯 For Triangular Ligaments

"Left is Longer, Right is Runt"

Left triangular ligament is longer than right