Reproductive Systems
Gonads
•  Produce
–  Sex cells (gametes)
–  Sex hormones
•  Male gonads = testes
–  Produce sperm cells
–  Secrete testosterone
•  Female gonads = ovaries
–  Produce eggs
–  Secrete estrogen and
progesterone
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Gonads
•  the key reproductive
organs because they:
–  Produce haploid gametes
(sex cells) via meiosis
–  Haploid: a cell that has only
one copy of each
chromosome (23 total)
–  Secrete sex hormones
•  Fertilization: fusion of egg
and sperm to
–  form a diploid zygote,
which will develop into a
new human
•  Diploid: refers to a cell
that has the normal two
copies of each
chromosome (46 total) –
one from each parent
Male reproductive
system
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Male reproductive
system
Male reproductive system
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Internal structure of
the testis and epididymis
Spermatogenesis
•  Beginning at puberty,
normal testes
produce 100-300
million sperm/day for
rest of life
•  It takes about 74 days
for sperm to develop
to maturity
•  Requires slightlylower-than-normal
body temperature
–  Thus, testes reside in
scrotum, away from
body core
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Spermatozoa (sperm)
Some male reproductive hormones
(Leydig cells)
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Female reproductive
system
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Female reproductive
system
(fallopian tube or uterine tube)
Female reproductive system
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Breast structure
The
ovarian
cycle
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The ovarian
and uterine
(menstrual)
cycles are
coordinated
by hormones
Review of the
ovarian and uterine cycles
•  Approximate follicle count: 2 million (fetal), 700,000
(at birth), 300,000 (at puberty), 400 ovulations
throughout reproductive years (1 per month from
puberty to menopause)
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