From puberty through middle age, both genders are
fully capable of reproduction. Upon reaching middle age,
females undergo
menopause
; the
female reproductive cycles dimin-
ish, and the women can no longer
reproduce. Between the ages of 40
and 50 the pool of remaining ovar-
ian follicles becomes exhausted. As a result, the ovaries
become less responsive to hormonal stimulation. The pro-
duction of estrogens declines, despite copious secretions
of FSH and LH by the anterior pituitary. Many women ex-
perience hot flashes and heavy sweating, which coincide
with bursts of GnRH release. Other symptoms of meno-
pause are headache, hair loss, muscular pains, vaginal dry-
ness, insomnia, depression, weight gain, and mood swings.
Some atrophy of the reproductive organs occurs in post-
menopausal women. Because of the loss of estrogens, most
women also experience a decline in bone mineral density
after menopause. Sexual desire does not decline, however;
it may be maintained by adrenal androgens.
In contrast, males can continue to reproduce well
into old age (80s or 90s), but the number of viable sperm
diminishes. At about age 55, a decline in testosterone
synthesis leads to reduced muscle strength, fewer viable
sperm, and decreased sexual desire. Although males are
capable of reproduction at older ages, many older males
develop reproductive system issues because of the age-
related changes of their cardiovascular systems. A poorly
functioning heart or blocked vascular flow will not allow
adequate blood to be routed to the reproductive system
for erection.
As for diseases of the reproductive systems, the risk of
uterine cancer peaks at about 65 years of age for women.
Cervical cancer is more common in younger women. For
men, enlargement of the prostate occurs in approximately
one-third of all males over age 60.
CONCEPT CHECK
___
1.
What signals the occurrence of puberty in the
female?
2.
What is menopause?
3.
What reproductive changes occur in men over
age 55?
menopause (MEN-
o-pawz) The termina-
tion of the menstrual
cycle.
Middle age
(ages 40-late 60s)
• In females, the number of viable follicles becomes exhausted, and the
production of estrogens declines (FSH, LH, and GnRH levels are high).
Menopause (the cessation of menses) begins.
• Most healthy men are still capable of reproduction, but some men
may have a decline in testosterone production and decreased sexual
desire.
Elderly
(ages 69 and older)
• Males may be reproductively capable into their 80s or 90s.
However, many have reduced muscle strength, fewer vi-
able sperm, and decreased sexual desire.
• Females are in menopause and are no longer capable of
reproduction.
Aging Alters Reproductive Capacity 503
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