1052
UNIT 5
Continuity
27
increases throughout the body, pulse rate and blood pressure
rise, and the uterus contracts rhythmically. As in males, orgasm
is accompanied by a sensation of intense pleasure followed by
relaxation. But unlike what is seen in males, a refractory pe-
riod does not follow orgasm, so females may experience multi-
ple orgasms during a single sexual experience. Female orgasm
is not required for conception. Indeed, some women never
experience orgasm, yet are perfectly able to conceive.
nipples become erect. Increased activity of the vestibular glands
and “sweating” of the vaginal walls lubricate the vestibule and
facilitate entry of the penis. Tese events, though more wide-
spread, are analogous to the
erection
phase in men. ±ouch and
psychological stimuli promote sexual excitement, which is me-
diated along the same autonomic nerve pathways as in males.
Te final phase of the female sexual response,
orgasm
, is
not accompanied by ejaculation. However, muscle tension
Table 27.1
Summary of Hormonal Effects of Gonadal Estrogens, Progesterone, and Testosterone
SOURCE, STIMULUS,
EFFECTS
ESTROGENS (MOSTLY ESTRADIOL)
PROGESTERONE
TESTOSTERONE
Major source
Ovary: developing follicles and
corpus luteum.
Ovary: mainly the corpus
luteum.
Testes: interstitial endocrine cells.
Stimulus for release
FSH (and LH).
LH.
LH and declining levels of inhibin
produced by the sustentocytes.
Feedback effects exerted
Both negative and positive feedback
exerted on anterior pituitary release
of gonadotropins.
Negative feedback exerted on
anterior pituitary release of
gonadotropins.
Negative feedback suppresses
release of LH by the anterior
pituitary and release of GnRH by the
hypothalamus.
Effects on reproductive
organs
Stimulate growth and maturation
of reproductive organs and breasts
at puberty and maintain their adult
size and function. Promote the
proliferative phase of the uterine
cycle. Stimulate production of
watery cervical mucus and activity of
fimbriae and uterine tube cilia.
Cooperates with estrogen in
stimulating growth of breasts.
Promotes the secretory phase of
the uterine cycle. Stimulates pro-
duction of viscous cervical mucus.
Progesterone surge after ovula-
tion enhances beating of cilia
in the uterine tube, promoting
meeting of sperm and oocyte.
Stimulates formation of male
reproductive ducts, glands, and
external genitalia. Promotes descent
of the testes. Stimulates growth
and maturation of the internal
and external genitalia at puberty;
maintains their adult size and
function.
 
Promote oogenesis and ovulation by
stimulating formation of FSH and LH
receptors on follicle cells. Stimulate
capacitation of sperm in the female
reproductive tract.
During pregnancy, quiets the
myometrium and acts with
estrogen to cause mammary
glands to achieve their mature
milk-producing state.
Required for normal spermatogenesis
via effects promoted by ABP, which
keeps its concentration high near
spermatogenic cells. Suppresses
mammary gland development.
 
During pregnancy stimulate growth
of the uterus and enlargement of
the external genitalia and mammary
glands.
 
 
Promotion of secondary
sex characteristics and
somatic effects
Promote long bone growth and
feminization of the skeleton
(particularly the pelvis); inhibit bone
reabsorption and then stimulate
epiphyseal closure. Promote
hydration of the skin and female
pattern of fat deposit.
 
Stimulates the growth spurt at
puberty; promotes increased skeletal
and muscle mass during adolescence.
Promotes growth of the larynx and
vocal cords and deepening of the
voice. Enhances sebum secretion and
hair growth, especially on the face,
axillae, genital region, and chest.
 
During pregnancy act with relaxin
(placental hormone) to induce
softening and relaxation of the pelvic
ligaments and pubic symphysis.
 
 
Metabolic effects
Generally anabolic. Stimulate Na
1
reabsorption by the renal tubules,
hence inhibit diuresis. Enhance
HDL (and reduce LDL) blood levels
(cardiovascular sparing effect).
Promotes diuresis
(antiestrogenic effect). Increases
body temperature.
Generally anabolic. Stimulates
hematopoiesis. Enhances the basal
metabolic rate.
Neural effects
Along with DHEA (an androgen
produced by the adrenal cortex) are
partially responsible for female libido
(sex drive).
 
Responsible for libido in males;
promotes aggressiveness.
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