Reproductive Systems
Male & Female

Function
 To ensure survival of the species
 To produce egg and sperm cells
 To transport and sustain these cells
 To nurture the developing offspring
 To produce hormones
 Other systems strive to maintain a state of
homeostasis

Male & Female
 Include:
 Reproductive organs called gonads that produce
gametes (reproductive cells) and hormones
 Ducts that transport gametes
 Accessory glands and organs that secrete fluids

Male & Female
 Production of hormones that permit the
secondary sex characteristics, such as breast
development in women and beard growth in
men

Male
 Functions
 To produce, maintain and transport sperm (the
male reproductive cells) and protective fluid
(semen)
 To produce and secrete male sex hormones
responsible for maintaining the male reproductive
system

Male
 Consists of:
 A pair of testes
 Scrotum
 A network of excretory ducts
 epididymis
 vas deferens/ductus deferens
 ejaculatory ducts
 Glands
 Seminal vesicles
 Prostate Gland
 Bulbourethral gland/ Cowper’s Glands
 Urethra
 Penis

http://www.uh.edu/~tgill2/image010.jpg

Male
 Testes / testicles
(Gonads)
 Produce sperm
(Spermatogenesis)
 Sperm production
begins at puberty and
continues throughout
the life of a male

Male
 Testes / testicles
(Gonads)
 Produce testosterone
 Hair patterns and voice
changes
 Development of the male
accessory organs
(prostate, seminal vesicles
etc.)
 Stimulates the effect of
protein building in the
body that is responsible
for the greater muscle
development and strength
of the male

Male
 Duct System
 Epididymis
 Sperm mature in
epididymis
 Vas
Deferens/Ductus
Deferens
 Transports mature
sperm to the
urethra
 Ejaculatory ducts
 empty into the
urethra

Male
 Seminal vesicles
 Attached to vas
deferens
 Produce a sugar-
rich fluid
(fructose) that
provides energy
to sperm

Male
 Prostate Gland
 Makes fluid

Male
 Bulbourethral Gland
 Secretes an alkaline
mucous to remove
any traces of acidic
urine in the urethra
and helps the semen
move quickly through
the urethra and out of
the penis

Male
 Urethra
 Tube that carries
urine from the
bladder to outside
of the body
 Also carries semen
out of the body

Male
 Penis
 Organ used to
deliver sperm into
the female
reproductive tract

Male
 Spermatogenesis
 Begins at puberty
 400 million sperm/day
 Three stages:
 Formation of spermatocytes
 Meiosis
 Spermiogenesis
 1st
stage: formation of
spermatocytes
 Spermatogonia divide
continuously by mitosis and
become primary
spermatocytes
 2nd
stage: meiosis I
 Each primary spermatocytes
(2n) undergoes meiosis I to
become 2 secondary
spermatocytes Each secondary
spermatocyte undergoes
meiosis II to become 2
spermatids
 3rd
stage: spermiogenesis
 Spermatids differentiate into
sperm

Male
 Anatomy of the Spermatozoa
 Head contains
 Nucleus with chromatid (genetic material)
 Acrosome with enzymes for penetrating egg
 Midpiece: mitochondria spiraled around the core of the tail
 Tail is an elaborate flagellum (allows sperm to swim)

Female
 Functions
 Produces the female egg cells
 Transports the eggs to the site of fertilization
 The fertilization of an egg by a sperm, occurs in
the fallopian tubes

Female
 Functions
 After fertilization, provides a place for a baby to
develop
 If fertilization does not take place, the system is
designed to menstruate
 Produces female sex hormones that maintain the
reproductive cycle.

Female
 Consists of:
 Vagina
 Uterus
 Ovaries
 Fallopian tubes

http://biology.clc.uc.edu/graphics/bio
105/repro%20female.jpg

Female
 Vagina
 Canal that joins
the cervix (the
lower part of
uterus) to the
outside of the
body
 Also is known
as the birth
canal

Female
 Uterus
 Hollow, pear-shaped
organ that is the home
to a developing fetus
 Divided into two parts:
 the cervix, the lower
part that opens into the
vagina
 Main body of the uterus,
called the corpus.
 The corpus can easily
expand to hold a
developing baby.
 A channel through the
cervix allows sperm to
enter and menstrual
blood to exit

Female
 Ovaries
 Oval-shaped glands that
are located on either side
of the uterus
 Produce eggs and
hormones.
 Hormones are:
 Estrogen-develop the
secondary sex
characteristics of a female
 Progesterone
http://www.ricancercouncil.org/img/cervical.gif

Female
 Fallopian Tubes
 Narrow tubes that are
attached to the upper part
of the uterus and serve as
tunnels for the egg cell to
travel from the ovaries to
the uterus
 Fertilization of an egg by a
sperm, normally occurs in
the fallopian tubes
 The fertilized egg then
moves to the uterus, where
it implants into the lining of
the uterine wall
http://www.ricancercouncil.org/img/cervical.gif

Female
 External Genitilia
 All structures are
collectively called as
vulva or pudendum
 The structures
included are:
 Mons pubis-mound of
adipose tissue
covered by the pubic
hair
 Labia majora-two folds
of skin containing
many adipose tissue
and sweat glands
 Labia Minora-no hair,
few sweat glands but
many sebaceous glands
 Clitoris-small, cylindrical
mass of erectile tissue
anterior to the labia
minora
 Vestibule-opening
between the 2 labia
minora
 Hymen-within the
vestibule; a thin fold of
tissue
 Skene’s glands-secrete
mucous
 Bartholin’s glands-
secrete mucous

Female
 Oogenesis
 Starts in fetal period
 No more oocytes made after about 7th month
 Developed only to early stage of meiosis I by birth and stops (called primary
oocyte)
 6-12 primordial oocytes each cycle selected to develop for ovulation (most
die)
 Only then is meiosis I completed
 Secondary oocyte is then arrested in meiosis II
 Meiosis II not completed (now an ovum) unless sperm penetrates its
plasma membrane
 Of the 4 daughter cells, only one becomes ovum (needs a lot of cytoplasm)
 The other 3 become “polar bodies”

Female
 The Menstrual Cycle
 The shedding of the lining of the uterus in
response to changes in hormonal levels.
 Cycle varies but within a range of 24-35 days

Female
 Mammary Glands
 Modified sweat glands
 Both sexes but function (normally) only in lactating female
 Produce milk to nourish baby
 Respond to hormonal stimulation
 Nipple surrounded by pigmented ring of skin, the areola
 Mammary glands consist of 15-25 lobes
 Each a distinct compound alveolar gland opening at the nipple
 Separated by adipose
 Smaller lobules composed of tiny alveoli
 Like bunches of grapes
 Don’t develop until half-way through pregnancy (ducts grow during
puberty)
 Milk passes from alveoli through progressively larger ducts
 Largest: lactiferous ducts, collect milk into sinuses

Female
 Pregnancy and Embryonic Development
 After ejaculation into the vagina, sperm swim to meet an egg
 Sperm live 5-7 days (need cervical mucus)
 Eggs live about 12-24 hours, so conception only occurs during this short window
 Fertilization occurs in the fallopian tube
 It takes 24 hours to move down one-third of the uterine tube. Fertilization
occurs in the upper two-thirds of the tube
 A fertilized egg is called a zygote
 Fertilization occurs at the moment the chromosomes from the male and
female gametes unite
 The zygote moves down the uterine tube, it divides by mitosis to form a hollow
sphere of cells called blastocyst.
 It embeds itself on the uterus by the seventh day and the 3 primary germ
layers are now being developed

 Ectoderm will develop into the skin and the nervous
system; Endoderm will form the linings of internal
organs and the Mesoderm will form muscles, bones
and other tissues.
 These tissues come from the blastocyst’s inner cell
mass
 The placenta is then formed. Once it is formed, the
three-layered embryo becomes surrounded by the
amnion
 The embryo becomes attached to the umbilical cord
 The pregnancy continues and the embryo grows. At
the ninth week, it is called a fetus.
 The placenta exchanges nutrients, oxygen and
wastes between the embryo/fetus and the mother

 Childbirth- called parturition and begins
with contractions of the smooth muscles
of the uterus called labor
 Labor-divided into 3 stages
 Dilation stage-cervix is fully dilated by the
head of the fetus and the amnion ruptures
releasing the amniotic fluid
 Expulsion stage-child moves through the
cervix and vagina, usually head first
 Placental stage- placenta detaches from the
uterus within 15 minutes after birth.