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  ON 
  THE 
  VISCERAL 
  ANATOMY 
  

  

  internally, 
  receives 
  the 
  blood 
  from 
  the 
  two 
  venae 
  cavae. 
  These 
  great 
  

   veins 
  unite 
  to 
  form 
  a 
  sinus 
  exterior 
  to 
  the 
  auricle, 
  and 
  communicate 
  

   with 
  it 
  by 
  means 
  of 
  a 
  single 
  narrow 
  opening 
  or 
  slit 
  : 
  this 
  opening 
  is 
  

   both 
  guarded 
  and 
  formed 
  by 
  two 
  membranous 
  valves, 
  which, 
  in 
  a 
  

   flaccid 
  condition 
  of 
  the 
  auricle, 
  are 
  loose 
  and 
  movable, 
  but, 
  when 
  the 
  

   auricle 
  is 
  dilated 
  or 
  stretched, 
  are 
  drawn 
  together 
  like 
  the 
  eyelids, 
  and 
  

   meeting 
  in 
  a 
  straight 
  line, 
  thus 
  interrupt 
  the 
  communication 
  between 
  

   the 
  auricle 
  and 
  the 
  sinus. 
  From 
  the 
  right 
  auricle 
  the 
  blood 
  passes 
  

   into 
  the 
  right 
  ventricle, 
  by 
  an 
  orifice 
  which 
  is 
  small, 
  and 
  situated 
  at 
  

   the 
  posterior 
  part 
  near 
  the 
  septum 
  of 
  the 
  heart. 
  Within 
  the 
  ventricle, 
  

   and 
  attached 
  around 
  that 
  portion 
  of 
  the 
  semi-circumference 
  of 
  this 
  

   opening 
  which 
  is 
  next 
  the 
  septum, 
  a 
  large 
  and 
  loose 
  valve 
  is 
  observed, 
  

   having 
  in 
  the 
  centre 
  of 
  its 
  floating 
  edge 
  a 
  hard 
  body 
  like 
  the 
  corpus- 
  

   culum 
  Arantii 
  of 
  the 
  human 
  aorta. 
  This 
  valve 
  is 
  placed 
  obliquely 
  as 
  

   regards 
  the 
  ventricle, 
  is 
  very 
  strong, 
  and 
  when 
  pushed 
  upwards 
  to- 
  

   wards 
  the 
  auricle, 
  is 
  found 
  to 
  close 
  the 
  communication 
  with 
  that 
  cavity 
  

   completely. 
  In 
  this 
  condition 
  of 
  the 
  valve, 
  however, 
  we 
  see 
  exposed 
  

   on 
  its 
  lower 
  side 
  another 
  orifice, 
  which 
  is 
  that 
  of 
  a 
  free 
  but 
  somewhat 
  

   oblique 
  passage, 
  going 
  through 
  the 
  septum 
  and 
  opening 
  into 
  the 
  left 
  

   ventricle. 
  It 
  follows, 
  from 
  the 
  attachment 
  of 
  this 
  valve 
  immediately 
  

   between 
  these 
  two 
  openings, 
  that 
  in 
  closing 
  the 
  one 
  it 
  exposes 
  the 
  

   other 
  : 
  that 
  is 
  to 
  say, 
  when 
  it 
  is 
  thrown 
  down 
  so 
  as 
  to 
  allow 
  the 
  blood 
  

   to 
  descend 
  from 
  the 
  right 
  auricle 
  into 
  the 
  right 
  ventricle, 
  it 
  is 
  placed 
  

   against 
  the 
  passage 
  leading 
  into 
  the 
  left 
  ventricle, 
  in 
  such 
  a 
  manner 
  as 
  

   to 
  prevent 
  its 
  entrance 
  into 
  that 
  cavity; 
  on 
  the 
  other 
  hand, 
  when 
  it 
  is 
  

   elevated, 
  and 
  placed 
  against 
  the 
  opening 
  leading 
  into 
  the 
  right 
  auricle, 
  

   it 
  leaves 
  free 
  and 
  exposed 
  that 
  which 
  communicates 
  with 
  the 
  left 
  ven- 
  

   tricle. 
  The 
  cavity 
  of 
  the 
  right 
  ventricle 
  is 
  marked 
  by 
  some 
  pits 
  or 
  

   depressions, 
  which 
  are 
  more 
  abundant 
  near 
  the 
  apex, 
  and 
  make 
  its 
  in- 
  

   ternal 
  surface 
  very 
  irregular. 
  Upon 
  the 
  posterior 
  inferior 
  face 
  of 
  this 
  

   ventricle, 
  commencing 
  near 
  the 
  apex, 
  and 
  going 
  up 
  to 
  terminate 
  at 
  the 
  

   roots 
  of 
  the 
  great 
  vessels 
  arising 
  from 
  this 
  cavity, 
  is 
  a 
  fleshy 
  column, 
  

   attached 
  along 
  one 
  edge 
  to 
  the 
  ventricle, 
  while 
  the 
  other 
  is 
  free 
  ; 
  it 
  

   increases 
  in 
  breadth 
  as 
  it 
  ascends, 
  and 
  forms 
  a 
  partial 
  septum, 
  dividing 
  

   as 
  it 
  were 
  the 
  ventricle 
  into 
  two 
  cavities. 
  At 
  the 
  point 
  of 
  termination 
  

   of 
  this 
  column 
  arise 
  three 
  great 
  arteries 
  ; 
  two 
  aortae 
  for 
  the 
  general 
  

  

  