Reproductive Systems
 The reproductive system includes the following components:
 Gonads, or reproductive organs that produce gametes and
hormones.
 Ducts that receive and transport the gametes.
 Accessory glands and organs that secrete fluids into the ducts of the
reproductive system or into other excretory ducts.
 Perineal structures that are collectively known as the external
genitalia.
 In both males and females, the ducts are connected to chambers and
passageways that open to the exterior of the body. The structures
involved constitute the reproductive tract.
Penis, Penis, Penis
Penis, Penis, Penis
 Spermatozoa are produced by the
process of spermatogenesis.
 First, stem cells called divide by
mitosis to produce two daughter
cells.
 one of which remains at that
location as a spermatogonium
while the other differentiates into
a primary spermatocyte.
 Primary spermatocytes are the cells
that begin meiosis, a specialized
form of cell division involved only in
the production of gametes
(spermatozoa in males, ova in
females).
 Primary spermatocytes give rise to
secondary spermatocytes that
differentiate into spermatids—that
subsequently differentiate into
spermatozoa.
 For each primary
spermatocyte that enters
meiosis, 4 spermatids are
produced.
 Meiosis produces gametes
that contain half the
number of chromosomes
found in somatic cells.
 For each cell entering
meiosis, the testes produce
four spermatozoa, whereas
the ovaries produce a
single ovum.
 The entire process takes
approximately 9 weeks.
 Mitochondrial activity provides the ATP required to move the
tail.
 The tail is the only flagellum in the human body. A flagellum, a
whiplike organelle, moves a cell from one place to another. The
flagellum of a spermatozoon has a complex, corkscrew motion.
 A mature spermatozoon lacks an endoplasmic reticulum, a
Golgi apparatus, and many other intracellular structures. The
loss of these organelles reduces the cell’s size and mass; it is
essentially a mobile carrier for the enclosed chromosomes, and
extra weight would slow it down.
 Because the cell lacks glycogen or other energy reserves, it
must absorb nutrients (primarily fructose) from the surrounding
fluid.
 Spermatogenesis begins at puberty and continues until
Vagina, vagina, vagina
Vagina, vagina, vagina
 A woman’s reproductive system produces sex hormones and
functional gametes, and it must also be able to protect and support
a developing embryo and nourish a newborn infant.
 The principal organs of the female reproductive system are the
ovaries, the uterine tubes, the uterus, the vagina, and the
components of the external genitalia.
 The ovaries, uterine tubes, and uterus are enclosed within an
extensive mesentery known as the broad ligament. The uterine tubes
run along the superior border of the broad ligament and open into
the pelvic cavity lateral to the ovaries.
 The mesovarium, supports and stabilizes the position of each ovary.
 The ovaries perform three main functions:
 (1) production of immature female gametes, or oocytes
 (2) secretion of female sex hormones, including estrogens and
progestins
 (3) secretion of inhibin, involved in the feedback control of pituitary FSH
production.
 Ovum production, or oogenesis, begins before a woman’s birth,
accelerates at puberty, and ends at menopause.
 Between puberty and menopause, oogenesis occurs on a monthly
basis as part of the ovarian cycle.
Ovaries
 Oogenesis begins during embryonic development, and primary
oocyte production is completed before birth.
 Each month after puberty, the ovarian cycle produces one or more
secondary oocytes from the pre-existing population of primary
oocytes.
 The number of viable and responsive primary oocytes declines
markedly over time, until ovarian cycles end at age 45–55.
 The ovaries have roughly 2 million primordial follicles at birth, each
containing a primary oocyte. By the time of puberty, the number has
dropped to about 400,000.
Uterus
 The uterus provides mechanical protection, nutritional support, and
waste removal for the developing embryo (weeks 1–8) and fetus
(week 9 through delivery). In addition, contractions in the muscular
wall of the uterus are important in ejecting the fetus at birth.
 The wall has a thick, outer, muscular myometrium and a thin, inner,
glandular endometrium,
 The uterus is a small, pear-shaped organ
 The uterine body is the largest portion of the uterus.
 The fundus is the rounded portion of the body superior to the
attachment of the uterine tubes.
 The cervix is the inferior portion of the uterus that extends from the
isthmus to the vagina. The tubular cervix projects about 1.25 cm (0.5 in.)
into the vagina.
Uterine Cycle
 We can divide the uterine cycle into three phases:
 (1) menses: degeneration of the endometrium, Eventually, the weakened arterial
walls rupture, and blood pours into the connective tissues of the functional zone.
 The sloughing off of tissue is gradual, and at each site repairs begin almost at
once.
 Nevertheless, before menses has ended, the entire functional zone has been lost.
 The process of endometrial sloughing, called menstruation, generally lasts from
one to seven days.
 Over this period roughly 35 to 50 ml of blood are lost. The process can be relatively
painless.
 The phases occur in response to hormones associated with the regulation of the
ovarian cycle.
Uterine Cycle
 (2) the proliferative phase: In the days after menses, the epithelial cells of
the uterine glands multiply and spread across the endometrial surface,
restoring the integrity of the uterine epithelium. Further growth and
vascularization result in the complete restoration of the functional zone
 (3) the secretory phase: the endometrial glands enlarge, accelerating
their rates of secretion, and the arteries that supply the uterine wall
elongate and spiral through the tissues of the functional zone.
 This activity occurs under the combined stimulatory effects of progestins and
estrogens. The secretory phase begins at the time of ovulation and persists as
long as the corpus luteum remains intact
 A new cycle then begins with the onset of menses and the disintegration
of the functional zone.
 The secretory phase generally lasts 14 days. As a result, you can identify
the date of ovulation by counting backward 14 days from the first day of
menses.
Uterine Cycle
Menopause
 The uterine cycle begins at puberty. The first cycle, known as
menarche, typically occurs at age 11–12. The cycles continue
until menopause, the termination of the uterine cycle, at age 45–
55.
 Regular appearance of uterine cycles is interrupted only by
circumstances such as illness, stress, starvation, or pregnancy.
 If menarche does not appear by age 16, or if the normal uterine
cycle of an adult woman becomes interrupted for six months or
more, the condition of amenorrhea exists.
 Primary amenorrhea is the failure to initiate menses.
 Transient secondary amenorrhea can be caused by severe physical
or emotional stresses.
Chlamydia—ChlamydiaRates by Sex, United States,
1990–2010
Rate (per 100,000 population)
750
Men
Women
Total
625
500
375
250
125
0
1990
1992
1994
1996
1998
2000
2002
2004
2006
Year
NOTE: As of January 2000, all 50 states and the District of Columbia have regulations that require
the reporting of chlamydia cases.
2008
2010
Gonorrhea—Rates, United States, 1941–2010
Rate (per 100,000 population)
500
400
300
200
100
0
1941
1946
1951
1956
1961
1966
1971
1976
Year
1981
1986
1991
1996
2001
2006
Syphilis—Reported Cases by Stage of
Infection, United States, 1941–2010
Cases (in thousands)
600
Primary and Secondary
Early Latent
Total Syphilis
500
400
300
200
100
0
1941
1946
1951
1956
1961
1966
1971
1976
Year
1981
1986
1991
1996
2001
2006
Chancroid—Reported Cases, United States, 1981–2010
Cases (in thousands)
5
4
3
2
1
0
1981
1983
1985
1987
1989
1991
1993
1995
Year
1997
1999
2001
2003
2005
2007
2009
Human Papillomavirus—Prevalence of High-risk and Low-risk
Types Among Females Aged 14–59 Years, National Health and
Nutrition Examination Survey, 2003–2006
Prevalence, %
60
Low-risk HPV*
High-risk HPV*
50
40
30
20
10
0
14–19
20–24
25–29
30–39
40–49
Age
* HPV = human papillomavirus.
NOTE: Error bars indicate 95% confidence intervals. Both high-risk and low-risk HPV types were detected in
some females.
SOURCE: Hariri S, Unger ER, Sternberg M, Dunne EF, Swan D, Patel S, et al. Prevalence of genital HPV among
females in the United States, the National Health and Nutrition Examination Survey, 2003–2006.
J Infect Dis. 2011;204(4):566-73
50–59
Genital Warts—Initial Visits to Physicians’ Offices,
United States, 1966–2010
Visits (in thousands)
500
400
300
200
100
0
1966
1969
1972
1975
1978
1981
1984
1987
1990
1993
1996
1999
Year
NOTE: The relative standard errors for genital warts estimates of more than 100,000 range from 18% to 30%.
SOURCE: IMS Health, Integrated Promotional Services™. IMS Health Report, 1966–2010.
2002
2005
2008
Genital Herpes—Initial Visits to Physicians’ Offices,
United States, 1966–2010
Visits (in thousands)
400
350
300
250
200
150
100
50
0
1966
1969
1972
1975
1978
1981
1984
1987
1990
1993
1996
1999
2002
Year
NOTE: The relative standard errors for genital herpes estimates of more than 100,000 range from 18% to 30%.
SOURCE: IMS Health, Integrated Promotional Services™. IMS Health Report, 1966–2010.
2005
2008
AIDS
More than one million people are living with HIV in the U.S.
One in five living with HIV is unaware of their infection.

Top ten states ranked by rate (per 100,000) of reported STD cases: United States, 2009

Rank
Primary and secondary syphilis
Chlamydia
Gonorrhea

1
Louisiana (16.8)
Mississippi (802.7)
Mississippi (246.4)

2
Georgia (9.8)
Alaska (752.7)
Louisiana (204.0)

3
Arkansas (9.6)
Louisiana (626.4)
South Carolina (185.7)

4
Alabama (8.9)
South Carolina (595.0)
Alabama (160.8)

5
Mississippi (8.1)
`Alabama (556.2)
Arkansas (156.2)

6
Texas (6.8)
Delaware (540.4)
Illinois (154.7)

7
Tennessee (6.5)
Arkansas (502.7)
North Carolina (150.4)

8
North Carolina (6.3)
New Mexico (478.4)
Michigan (147.0)

9
New York (6.1)
Tennessee (478.1)
Alaska (144.3)

10
Illinois (5.8)
New York (472.4)
Georgia (141.3)
 Most activities don't spread STDs!
 You cannot get an STD from everyday, nonsexual activities, such as:
 • giving blood
 • sitting next to an infected person
 • sitting on toilet seats
 • sharing eating utensils• touching doorknobs
 • using swimming pools
 How can you avoid STDs
 (monogamy) has sex with you only
 If you are not in a monogamous relationship, be sure to:
 • Use barrier methods like latex condoms. Latex condoms are your
best protection from STDs during intercourse. But remember, even
condoms are not 100% effective.
 • Limit the number of partners you have. The more partners you
have, the greater the risk of being exposed to an STD. Remember,
you can't tell if someone has an STD just by looking at them.
 • Have regular physical exams. Ask you physician to test for STDs if
you think you've been exposed. Regular tests help find STDs early,
when treatment can be most effective. Don't inject drugs. Sharing
needles or syringes can expose you to infected blood
 Waht other types of birth control help protect against STDs?
 Only latex condoms are considered effective protection
against STDs.
 Birth control pills, diaphragms, sponges, and other
contraceptives do not prevent STDs.
A lot of men carry condoms in their wallets. Is this a good
idea
No. Exposure to body heat, sunlight, and extreme cold can
all damage condoms and make them more likely to break.
Once I've had an STD, can I get it again?
Yes. Sex without a condom can result in getting an STD, no
matter what STD you've already had.