Liver Flashcards
Describe the Liver and its location
- It is the largest solid organ in the body.
- Intraperitoneal (inside the peritoneum and covered by a capsule, Glisson’s)
- Located in the RUQ (occupies a major portion of the right hypochondrium)
- Epigastrium (extends inferiorly)
- Left Hypochondrium (lateral into the left hypochondrium)
Describe the shape of the Liver
- Shape depends on patient’s body habitus (or morphotype)
a. Irregular
b. Hemispheric
c. Wedge-shaped
What is the weight of the Liver?
- The exact weight of a normal liver in adult women is 1,200g
- The exact weight of a normal liver in adult men is 1,600g
- The weight of the liver to total body weight is approximately 1/36th for an adult compared to approximately 1/18th for an infant
Differentiate the Right Lobe of the Liver with the Left Lobe
- Right Lobe is 2 to 3 times larger than the Left Lobe
- Along the midclavicular line, the normal longitudinal measurement of the Right Lobe is 13cm or less.
- The greatest transverse portion = 20 to 22.5cm
- The greatest AP measurement = 10 to 12.5cm
- The greatest length on the right surface = 13 to 15.5cm
*Obtaining liver measurements in the sagittal section will help detect Hepatomegaly (more than 17cm)
What is the Caudate and Right Lobe Ratio?
- Subcostal in true transverse plane
- Less than 0.65cm
Describe the Perihepatic Relationships
- Diaphragm superior, anterior and posterior
- Right Kidney indents posterior right lobe
- IVC posterior
- Visceral surface (inferior) in contact with abdominal organs
What is Glisson’s Capsule?
- It covers the liver.
- It is composed of two adherent layers; an outer serous layer that is derived from the visceral peritoneum and inner dense, fibroelastic connective tissue layer.
- It is named after the British physician, anatomist and physiologist and pathologist Francis Glisson.
- It contain blood, lymphatic vessels and completely covers the liver
- It surrounds the liver and encases the Hepatic Artery, Portal Vein and Bile Ducts within the liver at the porta hepatis.
What is Bare Area?
- It is a portion of the posterior surface of the liver without a peritoneal covering, this portion is in direct contact with the diaphragm.
- It represents an area where infection can spread from abdominal cavity to the thoracic cavity
What is Fossa’s?
- These are indentations in the liver.
- Gallbladder
a. Posterior inferior liver
b. Contains the main lobar fissure - IVC
a. Contains part of the the IVC
b. Between the caudate lobe and bare area of the liver
What are Fissures?
- These are groove or cleft in the liver in which structures run through
- Porta Hepatis ( is a fissure where the portal vein and hepatic artery enter the liver and the bile duct exits the liver.)
- Main Lobar Fissure
- Intersegmental
a. Right
b. Middle
c. Left - Each hepatic vein has fissure (canal) because they don’t want to crush the veins. Right, Left and Middle Fissure
What is the Interlobar Fissure?
The Interlobar Fissure divides the liver into Right Lobe and Left Lobe.
What is the Intersegmental Fissure?
The Intersegmental Fissure divides into Right Intersegmental Fissure (Anterior and Posterior segments) and Left Intersegmental Fissure ( Medial and Lateral segments)
What is the Sonographic Landmark for Right Intersegmental Fissure?
Sonographic Landmark: Right Hepatic Vein
What is the Sonographic landmark for the Left Intersegmental fissure?
The Sonographic Landmark for the Left Intersegmental Fissure is the Left Hepatic Vein/LHV; the ascending branch of LPV and inferiorly the ligamentum teres
What is the Main Lobar Fissure?
- The Main Lobar Fissure divides the liver into Right and Left Lobes.
- A short segment seen the Gallbladder Neck and RPV (Right Portal Vein)
- Middle Hepatic Vein runs through fissure
What is the Right Intersegmental Fissure?
- The Right Intersegmental Fissure divides the Right Lobe of the Liver into anterior and posterior segments.
- Right Hepatic Vein courses through it.
- Anterior Segment of the RT Lobe
- Posterior Segment of the RT Lobe
What is the Left Intersegmental Fissure?
- The Left Intersegmental Fissure divides the Left Lobe of the Liver into medial and lateral segments.
- The Left Hepatic Vein courses through it.
- Medial Segment of the LT Lobe
- Lateral Segment of the LT Lobe
What is the Fissure for the Ligamentum Venosum?
- It divides the caudate lobe from the lateral left segment.
- It contains the Ligamentum Venosum
- It contains the Hepatogastric Ligament
What are the ligaments for?
- Ligaments tethers the liver to the following:
a. Diaphragm
b. Anterior abdominal wall
c. Lesser curve of the stomach
d. Retroperitoneum - Ligament visualization helps idetify lobar anatomy; accurate localization of lobar structures and perihepatic fluid collections.
What it the Coronary Ligament?
- The Coronary Ligament connects the posterosuperior liver surface to the diaphragm.
- It consists of an anterior and posterior layer.
- These layers are continous on each side with the Right Triangular and Left Triangular Ligaments
- It defines the bare area of the liver.
What is the Falciform Ligament?
- The Falciform Ligament is a broad, thin anteroposterior fold of the parietal peritoneum.
- It runs from anterior to posterior on the left lobe of the liver and ends with ligamentum teres.
- It originates from the midportion of the coronary ligament; extends from the coronary ligaments
- It extends from the liver to the abdominal wall between the diaphragm and umbilicus.
What is the Ligamentum Teres?
- It is a round ligament.
- It is the fibrous cord resulting from the obliterated left umbilical vein
- It is the remnant of the fetal umbilical vein.
- It is located at the inferior liver margin.
What is the Ligamentum Venosum?
- It is the remnant of the ductus venosus.
- It inserts into the left branch of the portal vein.
- It is a continuance of the ligamentum teres within the left intersegmental fissure on the superior, visceral surface of the liver.
- It is anterior to the Caudate Lobe most likely on the left.
Describe the Anatomical Relationship of the Caudate Lobe
The Caudate Lobe is anterior to Ligamentum Venosum and posterior to IVC.
Explain the Fetal Circulation
- Umbilical vein carries oxygenated blood from placenta to fetus which ascends divides into two branches.
- The Left Branch joins the portal vein and enters the liver.
- The Right Branch, the ductus venosus flows directly into the IVC bypassing the liver.
- After birth, both veins close and exists as Ligaments.
- The Left Umbilical Vein becomes the Ligamentum Teres or Round Ligament.
- The Ductus Venosus becomes the Ligamentum Venosum.
What is the Gastrohepatic Ligament?
- It is also known as the Lesser Omentum.
- It is composed of two folds of visceral peritoneum.
- It originates on the undersurface of the liver, continuous with the Ligamentum Venosum.
- It courses caudally to attach to the lesser curvature of the stomach and to the first portion of the duodenum.
What is the Hepatoduodenal Ligament?
- The Hepatoduodenal Ligament surrounds the portal triad at the porta hepatis.
- It forms the anterior boundary of the epiploic foramen (Foramen of Winslow)
What is the Portal Triad?
The Portal Triad is composed of the Portal vein, Hepatic artery and Bile duct.
What is the Triangular Ligament?
- It is formed by the apposition of the upper and lower ends of the coronary ligament and extend from the diaphragm of the liver.
- The Right Triangular Ligament is attached to the border at the right extremity of the bare area and passes to the diaphragm.
- The Left Triangular Ligament is larger of the two and attaches to the superior surface of the left lobe where it lies anterior to the esophageal opening in the diaphragm.
Describe Liver Divisions
- Lobar divisions of the liver can be described as ANATOMIC based on the external landmarks and visceral surface of the liver or SEGMENTAL (FUNCTIONAL), based on internal landmarks and hepatic function.
What is the Anatomic Division of Liver?
- The Anatomic Division is based on external markings.
- It is a broad division that uses the Falciform Ligament to divide the liver into the right and left hepatic lobes classifies the Caudate and Quadrate Lobes as part of the right lobe.
- Anatomic Division divides the liver into:
a. Right
b. Left
c. Caudate
d. Quadrate - Visceral liver surface: “H” configuration
What is the Anatomical Division of the Caudate Lobe?
The Caudate Lobe is interposed between the following:
a. IVC - posteriorly
b. Left Liver Lobe - anteriorly and superiorly
c. Main Portal Vein - inferiorly
d. Ligamentum Venosum - anteriorly
What is the Anatomical Division of the Quadrate Lobe?
- It is on the visceral surface.
- It is described as the medial segment of the Left Lobe.
- It is bounded by the following:
a. Porta Hepatis - posteriorly
b. Inferior Margin of the Liver - anteriorly
c. Gallbladder Fossa on the right - laterally
d. Fissure for the Ligamentum Teres - on the left
Describe the Right Lobe in the Anatomic Division
- The Right Lobe is 6 times larger than the left, occupies the right hypochondrium.
- It is separated from the Left Lobe by the Falciform Ligament.
- The anterior portion is marked by Falciform Ligament.
- The posterior surfaces are marked by 3 Fossae: the Porta Hepatis, the Gallbladder and the IVC.
Describe the Left Lobe of the Liver in the Anatomic Division
- It is situated in the epigastric and left hypochondriac regions.
- It is separated from the Right Lobe of the Liver by the falciform ligament on its anterior surface.
- It is on the visceral surface.
- The fissure for the Ligamentum Teres separates from the quadrate lobe.
- The fissure for the Ligamentum Venosum separates from the caudate lobe.
What is the Segmental or Functional Liver Division?
- The sonographic landmarks used to identify lobes and segments; sonograhphers evaluate and document the liver using internal landmarks.
- The liver is divided into three lobes and 4 segments based on blood supply and biliary drainage.
1. Right Lobe - containing an anterior and a posterior segment
2. Left Lobe - containing a medial and lateral segment
3. Caudate Lobe