Liver Anatomy and Lobes

The largest solid organ in the human body, weighing approximately 1600g in males and 1400g in females.

A thin, fibrous capsule that surrounds the liver, providing structural support and protecting it.

The liver is divided into three main lobes: the left, right, and caudate lobes.

These are fibrous bands that connect the liver to surrounding structures, providing support and helping anchor it in place.

These are deep grooves or indentations in the surface of the liver, often housing blood vessels, bile ducts, or other structures.

The liver is a highly vascular organ, meaning it's rich in blood vessels. These vessels carry blood to and from the liver.

A network of tubes that carries bile, a fluid produced by the liver that aids in digestion, to the gallbladder and then to the small intestine.

The left lobe of the liver is further subdivided into medial and lateral segments by the left hepatic vein and ligamentum teres, a remnant of the fetal umbilical vein.

A space located lateral to the right lobe of the liver, anterior to the right kidney, and communicating with the right paracolic space.

Space located between the inferior edge of the right lobe of the liver and the right kidney.

Area between the superior border of the liver and the diaphragm.

The left lobe of the liver, situated posteriorly and superiorly, is known for its unique shape and location.

These segments represent the upper portions of the left lobe and are further divided into superior and inferior lateral sections.

These segments represent the central part of the left lobe.

These segments are located below the transverse plane of the liver.

These segments are positioned above the transverse plane of the liver.

The hepatic veins are responsible for draining deoxygenated blood from the liver directly into the inferior vena cava (IVC).

The hepatic vein waveform is triphasic, reflecting the pressure changes in the right atrium of the heart. It shows two antegrade waves (diastolic and systolic) and a smaller retrograde wave during atrial contraction (atrial kick).

The proper hepatic artery enters the liver at the porta hepatis, branching into right, middle, and left hepatic arteries. It provides approximately 30% of the liver's blood supply, carrying oxygenated blood to the liver.

The portal vein carries nutrient-rich blood from the digestive system to the liver. It branches into right and left portal veins at the porta hepatis, supplying 70% of the liver’s blood volume. It is characterized by its fibrin-containing walls.

Portal venous hypertension is a condition where the pressure in the portal vein system is elevated, usually above 10mmHg. It is often caused by liver disease or obstruction of the portal vein. It manifests with ascites, splenomegaly, and bleeding from varices.

A procedure where a stent graft is placed between a hepatic vein and the portal vein to alleviate symptoms from portal hypertension. Effectively bypassing the liver, it redirects portal venous flow to the IVC via the hepatic vein, often from the right portal vein to the right hepatic vein.

Liver inflammation or infection. It can be caused by various factors such as abscesses, candidiasis, echinococcal cysts, hepatitis, and schistosomiasis.

Occur in both ambeic and pyogenic forms. Symptoms include fever, chills, hepatomegaly, elevated Alk Phos, jaundice, abdominal pain. Often linked to travel abroad and linked to contamination of water or food.

Caused by the Candida species, commonly in immunocompromised individuals. Multiples small, hypoechoic masses appear on ultrasound with echogenic central cores, making a "wheel with a wheel" or "bullseye" appearance.

Infections from parasitic tapeworms. Often found in people with a history of traveling to underdeveloped countries. Two different appearances on ultrasounds: septated cystic mass or collapsed cyst within a cyst.

A general category of inflammatory and infectious disease of the liver. Types include A, B, and C, with symptoms like fever, fatigue, pain in the upper right area of your abdomen, joint pain, nausea or vomiting, diarrhea, loss of appetite, jaundice, dark urine, and pale/clay-colored stool.

Spread by fecal contamination, often through an infective person's stool. A vaccine is available if given within two weeks of exposure.

Spread via blood and other bodily fluids or contaminated needles. A vaccine is given in infancy, with treatment available with antiviral drugs for the 800,000 people in the US living with chronic Hep B.

Spread through blood and bodily fluids via contaminated needles. Afflicts 2.4 million people, with treatment via antiviral drugs.

An acquired disorder causing the accumulation of triglycerides (lipids) within hepatocytes. It is often reversible and associated with risk factors like obesity, alcohol abuse, hyperlipidemia, diabetes, hepatitis, metabolic disorder, ulcerative colitis.

A chronic degenerative disease resulting in disorganization of the liver's lobular architecture. Lobes are covered with fibrous tissue, parenchyma degenerates, and lobules are infiltrated with fat. Alcoholism, biliary obstruction, hepatitis, Budd-Chaiari syndrome, nutrient deficiency, and cardiac disease are common causes.

A tumor of glandular epithelium, more common in women, often related to oral contraceptive use. It is often asymptomatic or causes right upper quadrant pain. Increased incidence is often related to type I glycogen storage disease or von Gierke disease.

The second most common benign liver mass (after hemangiomas). It is often asymptomatic, but can cause right upper quadrant pain. It can be hyperechoic, hypoechoic, isoechoic, or mixed on ultrasound, often displaying a central hypoechoic area due to hemorrhage.

An infectious parasite that travels to the lungs and then the liver, causing increased echogenicity of the portal walls, atrophy in the right and left lobes of the liver, thickened gallbladder walls, and portosystemic collaterals.