Anatomy Of The Liver

Introduction to the Liver Learning Objectives • • • Describe the structure of the liver - Surfaces, peritoneal reflections, and its’ relations to other organs Describe the vascular supply to the liver ad its’ relationship to functional subdivisions Outline the internal structure of the liver Position of the liver • Hepatorenal recess (Morison’s pouch) – space separating liver from right kidney • Subphrenic recesses (left and right) – spaces separating liver from diaphragm • Subhepatic space – space separating liver from transverse colon • predominantly located in the right hypochondrium and epigastric areas, and extends into the left hypochondrium Range of movement of the liver • • lower when lying down mobile as it is attached to the diaphragm - expiration -> liver moves upwards - inspiration -> liver moves downwards Surfaces of the liver • diaphragmatic surface - • anterior, posterior and superior smooth and dome shaped direct contact with the diaphragm related to the concavity of the interior surface of the diaphragm ✓ separates it from the pleurae, lungs, pericardium, and heart Glisson’s layer ✓ Dense connective tissue ✓ Fibrous covering of the liver ✓ Innervated by branches of the lower intercostal nerves ✓ Distension the capsule -> sharp and well localised pain ✓ Attached over the entire surface expect posteriorly subphrenic recesses - superior extensions of the peritoneal cavity (greater sac)—exist between diaphragm and the anterior and superior aspects of the diaphragmatic surface of the liver separated into right and left recesses by the falciform ligament, which extends between the liver and the anterior abdominal wall • Hepatorenal recess - • the portion of the superacolic compartment of the peritoneal cavity immediately inferior to the liver is the subhepatic space Also, knowns as (hepatorenal pouch; Morison pouch) posterosuperior extension of the subhepatic space, lying between the right part of the visceral surface of the liver and the right kidney and suprarenal gland Fluid draining from the omental bursa flows into this recess Communicates anteriorly with the right subphrenic recess Bare surface - Where it lies directly contact with the diaphragm Ligaments • Falciform ligament - • Triangular ligaments - • Double layered Anchors the liver to the anterior abdominal wall and the diaphragm Asymmetrical Right and left components Covers the left lobe of the liver Short structure It begins at the apex of the bare area of the liver and is formed by the right path of the both layers of the coronary ligament Coronary ligament - Coronal ligament Attaches the liver to the diaphragm, right kidney, and adrenal glands Anteriorly ✓ continuous with falciform ligament ✓ divide to anchor the superior surface of the liver to the inferior surfaces of the diaphragm on the right-hand side - - • Ligamentum teres - • Round ligament of the liver A remnant of the left umbilical vein Ligamentum venosum - • Posteriorly ✓ Also, on the right side ✓ Attach posterior surface of the liver to the posterior abdominal wall, right kidney and its’ associated adrenal (suprarenal) gland The attachment of the coronal ligament to the liver and its’ division into the two layers create a triangular area that is devoid of peritoneum ✓ This is known as the bare area Remnant of the ductus venosum Occupies the fissure of the ligamentum venosum Lesser omentum - L-shaped Two parts: ✓ Hepatogastric ligament ✓ Hepatoduodenal ligament Visceral Surface of the Liver • Key information - • Triad vessels - • Covered by visceral peritoneum expect at portal hepatis Not smooth ✓ Has fissures and depressions and grooves Run from the free edge of the lesser omentum Enclosed within lesser omentum Left and right sagittal fissures - Right ✓ Anterior and posterior divisions ✓ Where the inferior vena cava fossa - Left ✓ Continuous grove ✓ Formed by fascia of round ligament and fissure for ligament venosum ✓ Extends from the notch on the anterior margin of the liver to the upper boarder of the posterior surface of the organ ➢ Separates right and left lobes Lobes of the liver • • • Superficial lobes Two topographical lobes - Right and left Two accessory lobes - Caudate - Quadrate Blood Supply to the Liver • Portal vein - • Portal route (e.g., intestines) and ends in the liver capillaries From liver goes to the heart via IVC 75% to 80% Hepatic artery - The other source is the hepatic artery -> transport blood from aorta to the liver as systemic blood Hepatic sinusoids (capillaries) -> central vein -> larger veins -> hepatic veins -> inferior vena cava Delivers oxygen and nutrients to the hepatic cells from their metabolism Portosystemic anastomosis • Gastroesophageal - • Caput Medusae - • - anastomosis between the intraparenchymal branches of the right division of the portal vein and retroperitoneal veins (systemic veins) that drain into the azygos, hemiazygos and lumbar veins (systemic veins). The site of this anastomosis is the bare area of the liver Omental and colon - • paraumbilical veins, which run in the ligamentum teres as portal veins, and small epigastric veins, which are systemic veins. The site of this anastomosis is the umbilicus The anus (haemorrhoids) - • Between left gastric veins (portal veins) and lower branches of the oesophageal veins -> drain into azygous vein and hemiazygos veins (systemic veins) The site of anastomosis is the lower oesophagus anastomosis between omental and colonic veins (portal veins) with the retroperitoneal veins (systemic veins) in the region of hepatic and splenic flexure. Ductus venous and IVC - anastomosis is between the ductus venosus (portal vein) and the inferior vena cava (systemic vein). - This is very rare and at the site of patent ductus venosus. Functional divisions