China
Africa
Explore chapters and articles related to this topic
Miscellaneous
Published in Bobby Krishnachetty, Abdul Syed, Harriet Scott, Applied Anatomy for the FRCA, 2020
Bobby Krishnachetty, Abdul Syed, Harriet Scott
Ductus venosusWhen: physiological closure at birth and complete obliteration in 2–5 days. It is replaced with a fibrous remnant, the ligamentum venosum, in a few months.How: cold and decreased PGE2 causes vasoconstriction that is hastened by clamping of the umbilical cord decreasing the blood flow.
SBA Answers and Explanations
Published in Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury, SBAs for the MRCS Part A, 2018
Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury
The ligamentum venosum is a remnant of the ductus venosus (a channel that shunts blood from the left umbilical vein directly into the inferior vena cava, during gestation, thereby bypassing the liver and preserving oxygenated blood for the head and neck region). The ligamentum teres (or round ligament), in the free edge of the falciform ligament, is a remnant of the left umbilical vein.
Liver
Published in Swati Goyal, Essentials of Abdomino-Pelvic Sonography, 2018
Liver is divided into left and right lobe and various segments depending on the vascular supply. It has a dual blood supply from the portal vein and the hepatic artery, both directing the blood toward the liver. Three hepatic veins drain the blood from the liver into IVC, exhibiting a trident appearance on USG. Left hepatic vein: Divides left lobe into medial and lateral segments.Middle hepatic vein: Separates left and right hepatic lobe, also separated by gallbladder (GB) fossa; courses within the main lobar fissure.Right hepatic vein: Divides right lobe into anterior and posterior segments.Quadrate lobe: Medial segment of left hepatic lobe. Located between round ligament and GB fossa.Caudate lobe: First segment of liver; bounded anteriorly by ligamentum venosum and posteriorly by IVC. It has its own blood supply and drainage. Should not be mistaken for a lymph node.
Variations in the vascular and biliary structures of the liver: a comprehensive anatomical study
Published in Acta Chirurgica Belgica, 2018
Burak Veli Ülger, Eyüp Savaş Hatipoğlu, Özgür Ertuğrul, Mehmet Cudi Tuncer, Cihan Akgül Özmen, Mesut Gül
Blood is supplied to the liver by the proper hepatic artery and drained from the liver by the hepatic portal vein. Other hepatic veins also provide venous drainage. The branches of the proper hepatic artery, hepatic portal vein, and common hepatic duct constitute the portal triad. The right portal triad exhibits a short course (1–1.5 cm) before entering the porta hepatis (a deep fissure on the inferior surface of the liver through which all neurovascular structures—except the hepatic veins—and the hepatic ducts enter or exit the liver). After entering the right lobe, the portal triad divides into anterior and posterior branches that supply the paramedian (V and VIII) and the lateral (VI and VII) segments [4]. The left portal triad continues to the top of the hepatoduodenal ligament and then moves 3–4 cm to the left to run under the quadrate lobe. The triad then turns forward, accessing segments II, III, and IV from the ligamentum venosum fissure [5,6]. The caudate lobe has a left portion of fixed size and a right portion that varies individually in size. Both the right and left portal triads drain blood from the caudate lobe and also drain bile. The caudate process, which is on the right, delivers venous blood to branches from the fork of the hepatic portal vein and the right branch of that vein; the left part of the caudate lobe delivers blood only to the left branch of the hepatic portal vein. The combined venous blood from the caudate lobe drains into the inferior vena cava via a single vein [7].