Anatomy
A
thorough
knowledge
of
the
anatomy
of
the
anal
canal
is
vital
for
effective
surgical
treatment
____________________
an
anal
fissure
.
The
anal
canal
____________________
be
defined
in
two
ways
,
as
follows
:
Functional
(
or
surgical
)
anal
canal
Anatomic
anal
canal
These
____________________
terms
are
often
used
interchangeably
,
even
though
____________________
do
not
mean
the
same
thing
.
The
____________________
anal
canal
is
approximately
4
cm
long
and
____________________
from
the
anal
verge
or
intersphincteric
groove
____________________
to
the
anorectal
ring
,
proximally
.
The
anatomic
____________________
canal
is
only
approximately
2
cm
long
and
extends
____________________
the
anal
verge
distally
to
the
dentate
line
proximally
.
The
dentate
____________________
is
the
junction
of
the
ectoderm
and
____________________
in
the
anal
canal
.
The
anal
verge
is
an
anocutaneous
line
approximately
2
cm
distal
____________________
the
dentate
line
.
The
anal
verge
marks
the
beginning
of
the
anal
canal
.
The
____________________
anal
sphincter
is
a
smooth
muscle
that
is
the
most
distal
extension
of
the
inner
circular
smooth
muscle
of
the
colon
and
the
____________________
.
It
is
2
.
5
-
4
cm
long
and
is
normally
2
-
3
mm
thick
.
The
internal
sphincter
is
not
under
voluntary
control
and
is
continuously
contracted
to
prevent
unplanned
loss
of
stool
.
