The reproductive tissues of male and female humans develop similarly in utero until about the seventh week of gestation when a low level of the hormone testosterone is released from the gonads of the developing male. Testosterone causes the primitive gonads to differentiate into male sexual organs. When testosterone is absent, the primitive gonads develop into ovaries. Tissues that produce a penis in males produce a clitoris in females. The tissue that will become the scrotum in a male becomes the labia in a female. Thus the male and female anatomies arise from a divergence in the development of what were once common embryonic structures.

1. HUMAN
REPRODUCTION
Ajay Kumar Gautam

2. REPRODUCTIVE EVENTS
 Humans sexual reproduction, viviparous, unisexual.
• Each sex has pair of gonads, reproductive duct and accessory structures.
• Sex organs – Testis( paired) male , ovaries (paired) Gamete formation, hormones
• Puberty
1. Gametogenesis – formation of gametes (sperms/ ova)
2. Insemination – transfer of sperms into the female genital tract
3. Fertilisation – fusion of male and female gametes leading to formation of zygote
4. Implantation – development of blastocyst and its attachment to the uterine wall
5. Gestation – embryonic development ( from conception to birth ) 6. Parturition–
delivery of the baby ( child birth ).

3. THE MALE REPRODUCTIVE
SYSTEM
REFERENCE
:
NCERT
DIAGRAMS

4. THE MALE REPRODUCTIVE
SYSTEM
 Located in pelvis region .
 The Male reproductive system includes:
A) A pair of testes.
B) Accessory ducts.
C) Accessory glands.
D) External genitalia

6.  Testis consists of three coverings,
i. Tunica Vaginalis(Outermost)
ii. Tunica albuginea(Middle)
iii. Tunica Vasculosa (Innermost)
 In each testis -250 compartments called testicular lobules .
 Each lobule contain 1-3 convoluted (coiled) called seminiferous tubule that joined to
form a network like structure called rete Testis.
 Rete Testis finally joined to form Vasa Efferentia and The vasa efferentia finally
joined with the Epididymis.

7.  Paired male gonads- sperm, hormones
 Oval in shape, length- 4 to 5 cm a width 2
to 3 cm
 Situated outside the abdominal cavity
within a pouch called scrotum.
 Scrotum – low temp. Of the testes (2-
2.5°C lower than the normal internal
body temperature) – spermatogenesis.
Testis consists of three coverings,
i. Tunica Vaginalis(Outermost)
ii. Tunica albuginea(Middle)
iii. Tunica Vasculosa (Innermost)
 An each testis -250 compartments called
testicular lobules .
 Each lobule contain 1-3 convoluted
(coiled) called seminiferous tubule.
THE TESTES

8. SEMINIFEROUS TUBULE –
SPERM PRODUCTION
 Lined on its inside by two types of cells
:
 a) Male germ cells (spermatogonia) –
meiotic divisions – sperm formation.
 b) Sertoli cells (supporting cells) –
provide nutrition to the germ cell.
 Regions outside the seminiferous
tubules called Interstitial spaces,
contain small blood vessels &
interstitial cells/ Leydig cells .
 Leydig cells – synthesise & secrete male
hormone Androgen ( testosterone).
 Other immunologically competent cells
are also present
TS OF
TESTES

9.  It is the highly coiled structure present
above the testis.
 Epididymis leaves the scrotum and runs
upward into the abdominal cavity.
 It has three parts i.e.
i. Caput Epididymis
ii. Corpus Epididymis
iii. Cauda Epididymis
 It helps in transfer the sperm from testis.
 The cauda Epididymis later on forms the vas
deferens that enters the abdominal cavity
and joins duct of seminal vesicle to form the
Ejaculatory duct.
Rete Testis
Vasa efferentia
Epididymis
Vas Deferens
Accessory Duct

10. https://teachmeanatomy.info/pelvis/viscera/urethra/
• Male urethera provides a common pathway for the
flow of urine and semen. It is much longer in female,
measuring about 20 cm .
• Prostatic Urethera:
• Begins as a continuation of the bladder neck and
passes through the prostate gland.
• It is the widest and most dilatable portion of the
urethra.
Membranous Urethera:
• It is the second part which is situated behind the
lower part o pubic symphysis and is smallest.
• It is the narrowest and least dilatable portion of the
urethra.
Penile Urethra :
• Penile urethera is situated in the Penis and is longest
part.
• In the glans (head) of the penis, the urethra dilates to
form the navicular fossa.
Parts of Urethra

11.  This is the copulatory organ of man. It is
cylindrical, erectile, pendulous organ
suspended from pubic region in front of
scrotum.
 It remains limp (Flaccid) but on sexual
arousal, it becomes long, hard, and erect,
ready for copulation ( coitus or intercourse).
 Erect human penis is, on average about 15-17
cm long.
 The penile mass is itself encased in a fibrous
sheath, called Tunica albuginea.
 The interior of the penis if formed of three
cylindrical cords of spongy, erectile (cavernous)
tissues
I. Corpora cavernosa (2)
II. Corpus urethrae or spongiosum.

12. B. Viewed from the side
A. Viewed from below.

13. Seminal vesicles:
 These are paired, tubular, coiled glands situated behind the urinary bladder.
 They secrete viscous fluid which constitute the main part of the ejaculates.
 Seminal fluid contains fructose, citric acid, inositol and prostaglandins.
• In rape cases, fructose help in diagnosis of victims.
Prostate Gland:
 Chestnut shaped gland and is a collection of 30-40 tubuloalveolar glands which lie
at the base of the bladder and surrounds the first part of the Urethra.
 It contributes alkaline component to the semen. ( Nutrilize acidic medium of
uterus and acidic medium of urine).
Bulbourethral glands or Cowper’s Gland :
 Two bulbourethral glands are pea-sized structures lying adjacent to the urethra at
the base of penis.
 They secrete a viscous mucus which acts as a lubricant.

14.  Semen is a mixture of sperm and seminal fluid,
which is the liquid portion of semen that consist
of secretions of the seminferous tubule, seminal
vesicles, Prostate gland and bulbourethral
glands.
 The average volume of semen in an ejaculation
is 2.5-5 ml, with sperm count of 200-300 million
sperms.
 Semen has a slightly alkaline pH of 7.2-7.7, due
to the higher pH and larger volume of fluid from
the seminal vesicles.
 The prostatic secretion gives semen a milky
appearance whereas the fluids from the seminal
vesicles and bulbourethral glands give it a sticky
consistency.
S -
E -
V -
E -
n
U -
P -
SEMENIFEROUS
TUBULE
URETHRA
EJACULATORY
DUCT
VAS
DEFERENS
EPIDIDYMI
S
RETE
TESTIS
VASA
EFFERENTIA
PENIS

15.  The female reproduction system is located in the pelvic
region.
It includes:
 1. A pair of ovaries
 2. A pair of oviduct.
 3. Uterus
 4. Cervix
 5. Vagina
 6. External genitalia.
 Oviducts, uterus, vagina – accessory ducts.
 A pair of the mammary glands ( nourishment of offspring)
 All parts are integrated structurally and functionally to
support the processes of ovulation, fertilisation, pregnancy,
birth and child care.

16.  Female reproductive system is more complex than male
reproductive system, because it has dual functions i.e.
 Production of Female gametes- Ova
 Nourishment of developing embryo(foetus) throughout
the Gestation Period (38 weeks)/ 9 months + 7 days
Parts of female Reproductive System:
 Pair of Ovaries
 pair of oviduct/ Fallopian tube
 Uterus/Womb/Hystera
 Vagina
 Vulva/ External Genitalia
 Mons Pubis
 Labia Majora
 Labia Minora
 Hymen
 Clitoris
 Glands: I Mammary Glands II. Bartholin’s Gland

17.  Vulva/ External Genitalia
 Mons Pubis- Fatty tissue cushion
covered by skin and pubic hair.
 Labia Major- Fleshy fold of skin &
covers the surrounding of vaginal
opening.
 Labia Minora- Paired folds of
tissue in the form of lips.
 Hymen- Vaginal orifice is covered
partially by membranous
diaphragm called hymen.
 Clitoris – Labia minora fuse
anteriorly to form a skin fold called
prepuce in front of a small erectile
organ, the clitoris.

18.  It is a modified sweat gland/ sebaceous
gland.
 Shape and size of beast is totally depending
upon the amount of fat (Adipose) present.
 There are number of mammary lobes are
present which contain the mammary
alveolus.
 The alveoli secrets milk and stores it.
 The alveoli open into mammary ducts and
several ducts join to form ampulla which
connected to the lactiferous duct through.
Which milk is sucked out.
 At the tip of the breast a small swelling
structure is found called nipple which is
surrounded by a thick dark skin called
areolae.

19. Prolactin- Milk producing hormone
Oxytocin- Milk ejecting hormone

20.  The process of formation of haploid
male gamete sperm in seminiferous
tubules of testis is called
spermatogenesis.
 The inner Wall of the Seminiferous
tubule contains two types of cells as
germ cells (spermatogonial cells) and
sertoli cells.
 Germl cells divides and develops
into sperms.The sertoli cell
nourishes the developing sperms.
 The spermatogenesis takes place in
two stages as spermatidgenesis and
sprermiogenesis.
Reference
:https://www.toppr.com/ask/question/draw-a-diagram-of-the-sectional-view-of-human-
seminiferous-tubule-and-label-its-parts
/

21.  Spermatidagenesis: It is the process of
formation of spermatids. It involves 3 sub
stages.
 Multiplication phase: The spermatogonial
cells undergoes repeated mitotic division and
forms large number of diploid spermatogonial
cells.
 Growth phase: The spermatogonial cells,
grow in size by cytoplasm and gets ready for
maturation. Now the spermatogonial cells
are called primary spermatocytes.
 Maturation phase: The diploid primary
spermatocyte undergoes first meiosis
resulting in the formation of two haploid cells
called secondary spermatocyte. This later
undergoes second meiotic division to produce
four haploid spermiatids.

22.  Spermiogenesis: It is The process of formation of inactive non-matile
spermiatid into active motile spermatozoa.
 The spermatid undergoes following structural change :
1. The smaII vesicles of Golgi complex fuse to form a large cup like
acrosome anterior to the nucleus.
2. The distal centriole elongates to form a tail.
3. The distal centriole elongates to form a tail.
4. The mitochondria forms a large mass at neck region.
5. The nucleus becomes elongated and forms a spherical shape.

23. HYPOTHALAMUS
ANTERIOR PITUITARY
LH
FSH
Leydig
Cell
Sertoli
Cells
Testosterone
Spermatogenesis
Inhibin
Negative
Feedback
STOP/
INHIBIT

24.  Mature sperm cell consist of a head, a neck, a middle
piece and a tail.
 A plasma membrane envelopes the whole body of
sperm.
 The sperm head contain very little cytoplasm, a cap
like structure, acrosome is present.
 They have a well-developed acrosome that covers 40 to
70 percent of the oval shaped head
 Acrosome is the product of Golgi complex and contains
a number of contents such as acrosin enzyme in the
acrosomal matrix.
 The midpiece is the central part of the sperm cell
between the head and the tail.
 Packed mitochondria that provide the energy requires
for swimming.
 The sperm tail is a thin, elongated structure that
makes up about 80 percent of the entire length of the
sperm.

26.  The process of formation of haploid female gamete
ovum in the follicles of ovary is called oogenesis.
 Oogenesis starts during embryonic stage.
 Germinal Epithelium of ovary divided mitotically
to produce million of gamete mother cell or
oogonia.
 No oogonia is formed or added after birth.
 Oogonia enters into meiosis-I , it proceeds
Prophase-I , get suspended and forms primary
oocytes.
 During puberty, the primary oocyte restarts its
meiotic division.

28.  Oogenesis takes place by three stages as follows:
 Multiplication Phase:
 The ovary is lined by germinal epithelium. These
cells undergo mitotic cell division to form large
number of diploid oogonia and follicle cells.
 Growth Phase:
 One of the diploid oogonia undergoes growth
increasing in cytoplasm and accumulation of yolk.
This enlarged oogonia is called primary oocyte.
 Maturation Phase:
 A fully grown primary oocyte undergoes 1 meiotic
division results in the formation of two unequaled
sized haploid cells.
 The large secondary oocyte and a small sterile
polocyte ( polar body) .The secondary oocyte
undergoes II meiotic division to form a large ootid
and a small sterile 2 polar body.
 The first polar body also undergoes equal division to
two cells.

30.  During copulation (coitus) semen
is released by the penis into the
vagina is called insemination.
 The motile sperms swim rapidly,
pass through the cervix, enter into
the uterus and finally reach the
junction of the isthmus and
ampulla (ampullary-isthmic
junction) of the fallopian tube.
 Fertilisation – if the ovum and
sperms are transported
simultaneously to the ampullary
isthmic junction.
 The process of fusion of a sperm
with an ovum is called
Fertilisation.

31.  Sperm contacts with zona pellucida of
ovum & induces changes in membrane that
blocks entry of other sperm .
 Acrosome of sperm secretes lytic enzymes
(hyaluronidase) helps in penetration into
the ovum cytoplasm through zona pellucida
& plasma membrane
 Meiotic division of secondary oocyte after
sperm enters plasma membrane of the
ovum.
 Second meiotic division – second polar body
and ovum / ootid .
 Nucleus of Ovum + Sperm = Zygote .
 Sex of baby decided this stage

32. https://www.britannica.com/science/fertilization-reproduction

33. Fertilization and passage of growing embryo
• Each gamete contains 23
Chromosome, the haploid
(n) number. Thus, fusion
of a sperm nucleus and an
egg nucleus makes a
zygote that have 46
chromosomes, thus
restoring the diploid (2n)
number.
• Male and female pronuclei
approach each other and
finally mixing up of
paternal and maternal
chromosomes
(Amphimixis) occurs
resulting in the formation
of synkaryon/zygote.

35.  Sex of the baby is decided during Fertilization.
The chromosome pattern in human female is
XX and that in male is XY.
 Therefore, all haploid gametes produced by the
female (ova) have the sex chromosomes X,
whereas in the male gametes (sperms) the sex
chromosome could be either X or Y, hence 50
percent of sperms carry X chromosome while
the other 50 percent carry the Y.
 After fusion of male and female gametes the
zygote would carry either XX or XY depending
on whether the sperm carrying X or Y has
fertilized the ovum.
 The zygote carrying XX would develop into a
female baby and XY would form a male.
 That’s why, scientifically it is correct to say that
the sex of the baby determined by the father
and not by the mother.

36.  The mitotic division starts as the zygote moves
through the Isthmus of the oviduct is called
Cleavage.
 Forms 2,4,8,16 daughter cells called blastomeres.
 Embryo with 8-16 daughter cells called Morula.
 The morula continues to divide and transform into
blastocyst as it moves further into the uterus.
 The blastomeres in the blastocyst are arranged
into an outer layer called trophoblast, and inner
group cells attached to the trophoblast called the
inner mass cells.
 The trophoblast layer then gets attached to the
endometrium and the inner mass cells gets
differentiated as Embryo.
 After attachment the uterine cells divide rapidly
and cover blastocyst.
 As a result, the blastocyst gets embedded in the
endometrium of Uterus.
 This is called implantation and leads to pregnancy.

38. SIGNIFICANCE OF
CLEAVAGE
 The distribution of the cytoplasm of
the zygote, amongst the
blastomeres.
 Increased mobility of the
protoplasm.
 The restoration of cell size and the
nucleocytoplasmic ratio
characteristic of the species.
 Unicellular zygote is converted into
multicellular embryo.

39.  After Implantation, finger like projections appear on
the trophoblast called chorionic villi, which are
surrounded by the uterine tissue and maternal
blood.
 The chorionie vill and uterine tissue become
interdigtated with each other and jolntly form a
structural and functional unit between developing
embryo (foetus) and materal body called placenta.
 The placenta facilitate the supply of oxygen and
nutrients to the embryo and also removal of carbon
dioxide and excretory/waste material produced by
the embryo.
 Placenta also acts as an endocrine tissue and
produces several hormones like human chorionic
gonadotropin (hCG), human placental lactogen
(hPL). Estrogens, progestogens, etc.
 In the later phase of pregnancy. A hormone called
relaxin is also secreted by the ovary.
 Let us remember that hCG, hPL and relaxin are
produced in women only during pregnancy.

40.  The antibiotics for measles, chicken pox,
polIo etc , are present in the blood of mother
and reach the embryo through placenta.
 Pathogenic viruses may also enter in embryo
through placenta.
 If a female takes some harmful chemicals,
liquor, drugs etc, during pregnancy, these
may cross the placenta and on reaching into
foetus may cause deformity during
organogenesis. {Eg: Thalidomide,
guaifenesin, Phenylephrine}.
 Teratogens: Agents inducing malformations
are called Teratogens. Foetus after 3 months
is less susceptible to Teratogens.

41. ROLE OF HUMAN CHORIONIC
GONADOTROPIN (HCG)
 The hCG maintains the ,corpus luteum and
stimulate it to secrete Progesterone.
 Maintains the endometrium.
 Prevents Menstruation.
 Increased secretion of mucus.
 Forms a protective plug during pregnancy.

42.  During pregnancy the levels of other hormones
estrogens, progestogens, cortisol, Prolactin,
thyroxine., Are increased several- folds in the
maternal blood.
 Increased production of these hormones is
essential for supporting the fetal growth,
Metabolic changes in the mother and
maintaince of pregnancy.

43.  Immediately after Implantation, the inner
cell mass differentiate into an outer layer
called ectoderm and an inner layer called
endoderm. A mesoderm soon appears
between
 These three layers gives rise to all tissues
(organ) in adults.
 Its needs to be mentioned here that the
inner cell mass contains certain cells called
stem cells which have the potency to give
rise to all the tissues and organs.
 In human beings, after one month of
pregnancy. The embryo’s heart is formed.
The first sign of growing foetus may be
noticed by listening to the heart sound
carefully through the stethoscope.

47.  The average duratíon of human pregnancy is about 9
months which is called the gestation period.
 Vigorous contraction of the uterus at the end of
pregnancy causes expulsion/delivery of the foetus.
This process of delivery of the foetus (childbirth) is
called parturition.
 Parturition is induced by a complex neuroendocrine
mechanism. The signals for parturition originate from
the fully developed foetus and the placenta which
induce mild uterine contractions called foetal ejection
reflex.
 This triggers release of oxytocin from the maternal
pituitary. Oxytocin acts on the uterine muscle and
causes stronger uterine contractions, which in turn
stimulates further secretion of oxytocin.
 The stimulatory reflex between the uterine
contraction and oxytocin secretion continues resulting
in stronger and stronger contractions. Thls leads to
expulsion of the baby out of the uterus through the
birth canal - Paturition.
 Soon after the infant is delivered, the placenta is also
expelled out of the uterus.

48.  The mammary glands of the female
undergo differentiation during
pregnancy and starts producing milk
towards the end of pregnancy by the
process called lactation.
 This helps the mother in feeding the
new-born. The milk produced during
the initlal few days of lactation is called
colostrum which contains several
antibodies absolutely essential to
develop resistance for the new-born
babies.
 Breast-feeding during the initial period
of infant growth is recommended by
doctors for bringing up a healthy baby.
 Antibodies provides passive Immunity
to the child.
 It contains essentially the same
concentrations of proteins and lactose
as milk but almost no fat.