RT Book, Section
A1 Doherty, Gerard M.
A2 Doherty, Gerard M.
SR Print(0)
ID 1105489553
T1 Biliary Tract
T2 CURRENT Diagnosis & Treatment: Surgery, 14e
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 9780071792110
LK accessmedicine.mhmedical.com/content.aspx?aid=1105489553
RD 2024/04/19
AB The  anlage  of  the  biliary  ducts  and  liver  consists  of  a  diverticulum  that  appears  on  the  ventral  aspect  of  the  foregut  in  3  mm  embryos.  The  cranial  portion  becomes  the  liver;  a  caudal  bud  forms  the  ventral  pancreas;  and  an  intermediate  bud  develops  into  the  gallbladder.  Originally  hollow,  the  hepatic  diverticulum  becomes  a  solid  mass  of  cells  that  later  recanalizes  to  form  the  ducts.  The  smallest  ducts—the  bile  canaliculi—first  appear  as  a  basal  network  between  the  primitive  hepatocytes  that  eventually  expands  throughout  the  liver  (Figure  25–1).  Numerous  microvilli  increase  the  canalicular  surface  area.  Bile  secreted  here  passes  through  the  interlobular  ductules  (canals  of  Hering)  and  the  lobar  ducts  and  then  into  the  hepatic  duct  in  the  hilum.  In  most  cases,  the  common  hepatic  duct  is  formed  by  the  union  of  a  single  right  and  left  duct,  but  in  25%  of  individuals,  the  anterior  and  posterior  divisions  of  the  right  duct  join  the  left  duct  separately.  The  origin  of  the  common  hepatic  duct  is  close  to  the  liver  but  always  outside  its  substance.  It  runs  about  4  cm  before  joining  the  cystic  duct  to  form  the  common  bile  duct.  The  common  duct  begins  in  the  hepatoduodenal  ligament,  passes  behind  the  first  portion  of  the  duodenum,  and  runs  in  a  groove  on  the  posterior  surface  of  the  pancreas  before  entering  the  duodenum.  Its  terminal  1  cm  is  intimately  adherent  to  the  duodenal  wall.  The  total  length  of  the  common  duct  is  about  9  cm.