a.  The  temporo-auricular  branch  has  usually  two  roots  which
embrace  the  middle  meningeal  artery  just  before  it  enters  the  skull
(see  §  82,  A,  6).  The  nerve  passes  outwards  behind  the  neck  of
the  jaw,  covered  by  the  parotid  gland,  then  ascends  over  the  root
of  the  zygoma  with  the  superficial  temporal  artery,  and  finally
ramifies  in  company  with  this  artery  upon  the  temple  and  side  of
the  head,  suppl3ring  the  integument  (see  §  76).  While  passing
behind  the  condyle  it  sends  one  or  two  delicate  filaments  to  the
articulation  of  the  jaw,  and  also  some  which  pierc )  the  cartilage  of
the  ear,  and  supply  the  skin  lining  the  meatus  auditorius.  It  has
already  been  stated  more  than  once  that  branches  proceed  from  this
nerve  to  the  upper  division  of  the  facial,  and  thus  endow  it  with
the  power  of  common  sensibility.
b.  The  inferior  dental  branch  descends  between  the  ramus  of
the  jaw  and  the  so-called  internal  lateral  ligament  of  the  jaw  to  the
dental  foramen,  which  it  enters  in  company  with  the  dental  artery.
It  then  runs  in  the  canal  prepared  for  it  in  the  cancellous  texture
of  the  jaw  immediately  below  the  fangs  of  all  the  teeth.  It  fur-
nishes a  series  of  filaments  which  ascend  through  the  canals  in  the
fangs  of  the  teeth  to  the  vascular  and  sensitive  pulp  in  their
interior.  Opposite  the  foramen  mentale  the  mental  branch  is  given
o/f  (see  §  75).  It  is  interesting  to  observe  that  the  same  nerve
which  supplies  the  teeth  supplies  the  corresponding  gums ;  hence
the  sympathy  existing  between  these  parts.
