Hepatitis B
Description
Hepatitis B is a chronic infection of the liver caused by HBV and can range from asymptomatic and unapparent to a framework acute fulminant and fatal, as well as a persistent subclinical form a rapidly progressive chronic liver disease to cirrhosis or even hepatocellular carcinoma.
Hepatitis B is widespread globally, according to the World Health Organization there are about 400 million carriers of the virus worldwide and about 600,000 people die each year from the consequences of the disease. However, hepatitis B can be prevented with the vaccine available today, that has to be 95% effective in preventing infection and its chronic consequences.
Anatomy
The liver, the largest organ in the body, and weighs about 1,5 kg, in the adult.
Wedge-shaped, it lies under the diaphragm, mainly in the right hypochondrium.
There are two surfaces: a rounded diaphragmatic surface and an irregular visceral (inferior) surface.
The diaphragmatic surface is rounded and convex, fitting closely to the diaphragm and its sharp inferior border separates it from the visceral surface.
The visceral surface is set obliquely, facing downwards, backwards and to the left – it is divided into a right and smaller left lobe by the interlobar fissure, the ligamentum venosum superiorly and the ligamentum teres below.
The ligamentum venosum is a remnant of the ductus venosus, which, in the foetus, connects the umbilical vein and inferior vena cava, and allows blood to bypass the liver.
The ligamentum teres is the obliterated left umbilical vein.
The right lobe contains the:
- Small quadrate lobe anteriorly between the interlobar fissure and the gallbladder
- Caudate lobe behind the interlobar fissure and the inferior vena cava, separated by the porta hepatitis, a transverse sulcus through which pass the:
- portal vein
- hepatic artery
- common hepatic duct
- lymph
The liver is largely covered by peritoneum, folds of which are reflected onto the anterior abdominal wall, diaphragm and stomach.
References
Abrahams P, Craven J, Lumley J. Illustrated Clinical Anatomy. Second Edition. Hodder Arnold. London, UK. 2011;Chapter 7:101.
Stevens A, Lowe JS, Young B. Wheater’s Basic Histopathology. A colour atlas and text. Fourth Edition. Churchill Livingston, an imprint of Elsevier Science Ltd. 2003:155.
Schiff ER, Sorrell MF, Maddrey WC. Schiff’s Diseases of the Liver. Tenth Edition. Volume One. Lippincott Williams & Wilkins. Philadelphia, USA. 2007;Chapter 30:823.
Foster GR, Reddy KR. Clinical Dilemmas in Viral Liver Disease. Wiley-Blackwell. Chichester, West Sussex, UK. 2010:13.
Schiff ER, Sorrell MF, Maddrey WC. Schiff’s Diseases of the Liver. Tenth Edition. Volume One. Lippincott Williams & Wilkins. Hepatitis B. 2007;Chapter 29:745-786.
Foster GR, Reddy KR. Clinical Dilemmas in Viral Liver Disease. Wiley-Blackwell. Chichester, West Sussex, UK. 2010;Chapter 36:168.