The  blood  supply  is  derived  from  the  external  carotid  artery.  The
facial  artery  gives  off  the  ascending  pharyngeal,  the  tonsillar  and  the
ascending  palatine.  The  superior  thyroid  is  distributed  to  the  upper
portion  of  the  larynx  and  the  inferior  thyroid  to  its  lower  portion.
The  pharynx  is  subdivided  into  the  naso-pharynx,  the  oro-pharynx,
and  the  laryngo-pharynx.  The  naso-pharynx  extends  to  the  edge
of  the  soft  palate;  the  oro-pharynx  from  this  to  a  line  drawn  through
the  horn  of  the  hyoid  bone;  the  laryngo-pharynx  extends  from  this
termination  to  a  plane  drawn  through  the  base  of  the  cricoid  cartilage.
The  mucous  membrane  covering  the  naso-pharynx  is  of  the  strati-
fied ciliated  variety.  The  oro-pharynx  is  lined  with  squamous  epi-
thelium, and  the  laryngo-pharynx  with  squamous  and  ciliated  epithe-
lium.
The  stratified  squamous  variety  of  epithelium  covers  the  vocal
cords,  arytenoid  cartilages,  columnal  cartilage  and  the  remaining
portion.  The  conglomerate  and  follicular  glands  are  both  numerous
in  the  naso-pharynx.  The  conglomerate  glands  are  numerous  over
the  pharyngeal  surface  of  the  soft  palate  and  the  posterior  wall  of
the  Eustachian  meatus.
The  follicular  glands,  or  the  tonsil  of  Luschka,  often  spoken  of  as
the  third  tonsil,  occupy  the  vault  of  the  pharynx  and  frequently  extend
downward,  encroaching  upon  the  Eustachian  orifice.  They  are

61


62  DISEASES   OF   EAR,    NOSE  AND   THROAT.
present  at  birth  but  should  undergo  atrophy  about  the  tenth  year
of  life.
Rosenmiiller's  fossae  are  situated  on  each  lateral  wall  of  the  pharynx,
about  midway  between  the  Eustachian  orifice  andthepost-pharynegal
wall.
