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The Male Reproductive System- Sperm FormationVersión en línea
This game will help you retain information learned about the formation of sperm
Each
testis
is
an
oval
structure
about
5
cm
long
and
3
cm
in
diameter
.
A
tough
,
white
fibrous
connective
tissue
capsule
,
the
,
surrounds
each
testis
and
extends
inward
to
form
septa
that
the
organ
into
lobules
.
There
are
about
250
lobules
in
each
testis
.
Each
lobule
contains
one
to
four
highly
coiled
tubules
that
converge
to
form
a
single
straight
tubule
.
The
straight
tubule
leads
into
the
testis
,
a
tubular
network
on
one
side
of
the
testis
.
Short
ducts
exit
the
testes
.
Interstitial
cells
,
which
produce
male
sex
,
are
located
between
the
seminiferous
tubules
within
a
lobule
.
Sperm
are
produced
by
the
within
the
seminiferous
tubules
.
A
transverse
section
of
a
seminiferous
tubule
shows
that
it
is
packed
with
cells
in
various
stages
of
spermatogenesis
.
Interspersed
with
these
cells
,
there
are
large
cells
that
from
the
periphery
of
the
tubule
to
the
,
These
large
cells
are
the
supporting
,
or
sustentacular
,
cells
,
which
support
and
the
other
cells
.
Early
in
embryonic
development
,
primordial
germ
cells
enter
the
testes
and
differentiate
into
,
immature
cells
that
remain
dormant
until
.
Spermatogonia
are
cells
,
each
with
chromosomes
(
23
pairs
)
,
that
are
located
around
the
periphery
of
the
seminiferous
tubules
.
At
puberty
,
hormones
these
cells
to
begin
dividing
by
mitosis
.
Some
of
the
daughter
cells
produced
by
mitosis
remain
at
the
periphery
as
spermatogonia
.
Others
are
pushed
toward
the
lumen
,
undergo
some
changes
,
and
become
primary
,
like
spermatogonia
,
are
diploid
and
have
46
.
Each
primary
spermatocyte
goes
through
the
first
meiotic
division
,
meiosis
I
,
to
produce
two
secondary
spermatocytes
,
each
with
23
chromosomes
.
Just
before
this
division
,
the
material
is
replicated
so
that
each
chromosome
consists
of
two
strands
,
called
,
that
are
joined
by
a
centromere
.
During
meiosis
I
,
one
chromosome
,
consisting
of
two
chromatids
,
goes
to
each
secondary
spermatocyte
.
In
the
second
meiotic
division
,
meiosis
II
,
each
secondary
spermatocyte
divides
to
produce
two
.
There
is
no
replication
of
genetic
material
in
this
division
,
but
the
centromere
divides
so
that
a
single
-
stranded
chromatid
goes
to
each
cell
.
As
a
result
of
the
two
divisions
,
each
primary
spermatocyte
produces
four
spermatids
.
During
spermatogenesis
there
are
cellular
divisions
,
but
only
one
of
DNA
so
that
each
spermatid
has
chromosomes
,
one
form
each
pair
oin
the
original
primary
spermatocyte
.
Each
sucessive
stage
in
spermatogenesis
is
toward
the
center
of
the
tubule
so
that
the
more
cells
are
at
the
periphery
and
the
more
cells
are
the
nearer
the
center
.
Spermatogenesis
differs
from
mitosis
because
the
resulting
cells
have
only
half
the
number
of
as
the
original
cell
.
When
the
sperm
cell
nucleus
unites
with
an
cell
nucleus
,
the
full
number
of
chromosomes
is
restored
.
If
sperm
and
egg
cells
are
produced
by
mitosis
,
then
each
successive
generation
would
have
the
number
of
chromosomes
as
the
preceding
one
.
The
final
step
in
the
development
of
sperm
is
called
.
In
this
process
,
the
spermatids
formed
from
spermatogenesis
become
mature
,
or
sperm
.
The
mature
sperm
cell
has
a
head
,
midpiece
,
and
tail
.
The
head
,
also
called
the
region
,
contains
the
23
chromosomes
surrounded
by
the
nuclear
membrane
.
The
tip
of
the
head
is
covered
by
an
acrosome
,
which
contains
that
help
the
sperm
penetrate
the
female
.
The
midpiece
,
also
called
the
region
,
contains
mitochondria
that
provides
adenosine
triphosphate
.
The
tail
,
also
called
the
region
,
is
typical
flagellum
for
locomotion
.
The
sperm
are
released
into
the
lumen
of
the
seminiferous
tubule
.
Leaves
the
,
and
enters
the
,
where
they
undergo
their
final
and
become
capable
of
a
female
gamete
.
Sperm
production
begins
at
and
continues
throughout
the
of
a
male
.
The
entire
process
,
beginning
with
a
primary
,
takes
about
days
.
After
ejaculation
,
the
sperm
can
live
for
about
in
the
female
reproductive
tract
.
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