28.  Profunda  artery. — This  is  the  chief  branch  of  the  femoral
arter}',  and  is,  in  fact,  the  proper  nutritious  artery  of  the  thigh.  It
arises  from  the  outer  and  back  part  of  the  femoral,  about  one  and  a
half  or  two  inches  below  the  crural  arch,  and  rims  down  behind
the  femoral  till  it  reaches  the  tendon  of  the  adductor  longus ;  here
the  profunda  passes  behind  the  adductor,  and  is  finally  lost  in  the
hamstring  muscles.  We  obsen'e,  in  most  subjects,  that  for  a  short
distance  after  its  origin  it  lies  rather  on  the  outer  side  of  the
femoral,  over  the  psoas  muscle,  so  that  in  this  situation  it  might  be
mistaken  for  the  femoral  itself, — indeed,  such  an  error  has  actually
occurred  in  practice.  It  soon,  however,  gets  quite  behind  the
femoral,  but  is  never  in  actual  contact  with  it,  for  the  two  arteries
are  separated  by  their  corresponding  veins.
The  profunda  gives  off  it,s  branches  generally  in  the  following
order: — 1,  the  internal  circumflex;  2,  the  external  circumflex;
3,  the  perforating.
a.  The  internal  circnmflex  sinks  deep  into  the  thigh  between
the  psoas  and  pectineus  muscles.  Here  for  the  present  we  lose  it ;
but  we  shall  find  it  again  in  the  dissection  of  the  back  of  the  thigh,
between  the  adductor  magnus  and  the  quadratus  femoris.  It
supplies  numerous  branches  to  the  muscles  in  its  neighbourhood, —
namely,  to  the  pectineus,  psoas,  the  adductors,  and  the  quadratus
femoris.  It  also  sends  branches  to  the  hip-joint,  and  one  espe-
cially which  runs  through  the  no:ch  in  the  acetabulum  to  the
ligamentum  teres.
