Chapter 27
The Reproductive System
1035
27
Anatomy of the Female
Reproductive System
Te reproductive role of the female is far more complex than
that of a male. Not only must she produce gametes, but her body
must prepare to nurture a developing fetus for approximately nine
months.
Ovaries
, the
female gonads
, are the primary reproduc-
tive organs of a female, and like the male testes, ovaries serve a
dual purpose: Tey produce the female gametes (ova) and sex
hormones,
estrogen
and
progesterone
(pro-ges
9
tĕ-rōn). Estro-
gen includes
estradiol
,
estrone
, and
estriol
, but estradiol is the most
abundant and is most responsible for estrogenic effects in humans.
As illustrated in
Figure 27.12
, a female’s
internal genitalia
her ovaries and duct system—are mostly located in the pelvic cav-
ity. Te female’s accessory ducts, from the vicinity of the ovary to
the body exterior, are the
uterine tubes
, the
uterus
, and the
vagina
.
Tey transport or otherwise serve the needs of the reproductive
cells and a developing fetus. Te external sex organs of females are
referred to as
external genitalia
.
The Ovaries
Describe the location, structure, and function of the
ovaries.
Te paired ovaries flank the uterus on each side (Figure 27.12).
Shaped like an almond and about twice as large, each ovary is
grow and increase in density, and skeletal muscles increase in
size and mass. Te last two effects are o±en referred to as the
somatic effects
of testosterone (
soma
5
body). ²estosterone also
boosts basal metabolic rate and influences behavior. It is the
basis of the male libido, whether heterosexual or homosexual.
As noted later (p. 1053), the adrenal androgen DHEA appears
to be more important than testosterone in creating or driving
the
female
libido.
In embryos, testosterone masculinizes the brain. ²estoster-
one also appears to continue to shape certain regions of the
male brain well into adult life, as indicated by the differences in
males’ and females’ brain areas involved in sexual arousal (for
example, the amygdala).
Te testes are not the only source of androgens. Te adrenal
glands of both sexes also release them. However, the relatively
small amounts of adrenal androgens are insufficient to support
normal testosterone-mediated functions, so we can assume that
it is the testosterone production by the testes that supports male
reproductive function.
Check Your Understanding
16.
What is the HPG axis?
17.
How does FSH indirectly stimulate spermatogenesis?
18.
What are three secondary sex characteristics promoted by
testosterone?
For answers, see Appendix H.
Peritoneum
Infundibulum
Uterine tube
Ovary
Uterus
Round ligament
Vesicouterine pouch
Urinary bladder
Pubic symphysis
Mons pubis
Urethra
Clitoris
External urethral
orifice
Hymen
Labium minus
Labium majus
Suspensory ligament
of ovary
Uterosacral
ligament
Perimetrium
Rectouterine
pouch
Rectum
Posterior fornix
Cervix
Anterior fornix
Vagina
Anus
Urogenital diaphragm
Greater vestibular
gland
Fimbriae
Figure 27.12
Internal organs of the female reproductive system, midsagittal section.
(For a related image, see
A Brief Atlas of the Human Body
, Figure 74.)
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