The document provides a detailed overview of human reproduction, focusing on the male and female reproductive systems. It outlines the anatomy and functions of various reproductive organs, including the testes, penis, ovaries, and uterus, along with the processes of spermatogenesis and ovulation. Additionally, it describes the menstrual cycle and hormonal regulation in females, emphasizing the roles of various glands and hormones involved in reproduction.

1. HUMAN
REPRODUCTION
By Biswanath prusty

2. INTRODUCTION
The reproductive system is a collection of internal and external organs —in both males and females —
that work together for the purpose of procreating.
Due to its vital role in the survival of the species, many scientists feel that the reproductive
system is among the most important systems in the entire body.
Of the body’s major systems, the reproductive system is the one that differs most between
sexes, and the only system that does not function until puberty.
The male reproductive system is responsible for delivering sperm to the female reproductive system

3. • Reproduction is the production of
young ones by an organism.
• Humans are sexually reproducing and
viviparous (animal which birth an
offspring).
HUMAN REPRODUCTION
HUMAN REPRODUCTIVE
SYSTEM
MALE
REPRODUCTIVE
SYSTEM
FEMALE
REPRODUCTIVE
SYSTEM

4. MALE REPRODUCTIVE SYSTEM

5. The male reproductive system consists of the following
organs
2 testes 2 epididymides in the scrotum
2 deferent ducts (vas deferens) 2 spermatic cords 2 seminal vesicles
2 ejaculatory ducts 1 prostate gland 1 penis

6. MALE REPRODUCTIVE SYSTEM
Male
repr
oduc
tive
syste
m
Paired testes
Accessory
ducts
Rete testis
Vasa efferentia
Epididymis
Vas deferens
Accessory
glands
Prostate gland (1)
Seminal vesicles (2)
Cowper’s (bulbo-
urethral) glands (2)
External
genitalia (Penis)

8. 1. PAIRED TESTES
• Primary sex organs that produce sperms &
testosterone.
• Testes are formed within abdomen.
• Soon after the birth or at the 8th month of
pregnancy, they descent into the scrotal sac
(scrotum) through inguinal canal.
• They are about 4.5 cm long, 2.5 cm wide and
3 cm thick and are suspended in the scrotum
by the spermatic cords. They are surrounded
by three layers of tissue.
• The low temperature (2-2.50 C less than the
body temperature) of scrotum helps for
proper functioning of testes and for
spermatogenesis.
MALE REPRODUCTIVE
SYSTEM

10. • Each testis is oval in shape.
• Length 4-5 cm, width: 2-3 cm.
• Each testis has about 250 testicular
lobules.
• Each lobule contains 1-3 coiled
seminiferous tubules.
• Seminiferous tubule is lined internally
with spermatogenic cells
(spermatogonia or male germ cells) &
Sertoli cells (supporting cells).
• Sertoli cells give shape and
nourishment to developing
spermatogonia.
1. PAIRED TESTES
MALE REPRODUCTIVE
SYSTEM

11. MALE REPRODUCTIVE
SYSTEM
1. PAIRED TESTES

12. 1. PAIRED TESTES
MALE REPRODUCTIVE
SYSTEM
• The regions outside the
seminiferous tubules (interstitial
spaces) contain
➢ Small blood vessels.
➢ Interstitial cells or Leydig cells.
➢ Immunologically competent
cells.
• Leydig cells secrete testicular
hormones (androgens).

13. 2. ACCESSORY DUCTS
MALE REPRODUCTIVE
SYSTEM
Rete testis
(irregular cavities)
Vasa efferentia
(series of fine tubules)
Epididymis
(stores sperms temporarily)
Vas deferens
Vas deferens joins with a duct of seminal vesicle to form common-ejaculatory duct.

14. 2. ACCESSORY DUCTS
MALE REPRODUCTIVE
SYSTEM
Urethral meatus
Urethra
Common ejaculatory duct
Vas deferens
Epididymis
Vasa efferentia
Rete testis
Seminiferous tubules
Conduction of sperms through Accessory ducts
The urethra receives the ducts of prostate and Cowper’s
glands and passes through the penis.

17. Ejaculation
During ejaculation, which occurs at the point of
male orgasm, spermatozoa are expelled from the
epididymis and pass through the deferent duct, the
ejaculatory duct and the urethra. The semen is propelled
by powerful rhythmical contraction of the smooth muscle
in the walls of the deferent duct; the muscular contractions
are sympathetically mediated. Muscle in the walls of the
seminal vesicles and prostate gland also contracts, adding
their contents to the fluid passing through the genital
ducts. The force generated by these combined processes
leads to emission of the semen through the external
urethral sphincter.
Sperm comprise only 10% of the final ejaculate,
the remainder being made up of seminal and prostatic
fluids, which are added to the sperm during male orgasm,
as well as mucus produced in the urethra. Between 2 and
5 ml of semen are produced in a normal ejaculate, and
contain between 40 and 100 million spermatozoa per ml.
If not ejaculated, sperm gradually lose their fertility after
several months and are reabsorbed by the epididymis.

18. 3. ACCESSORY GLANDS
MALE REPRODUCTIVE
SYSTEM
• They include
➢ A pair of seminal vesicles.
➢ A prostate gland.
➢ A pair of Cowper’s (bulbo-urethral)
glands.
• Their collective secretion is called seminal
plasma. It is rich in fructose, Ca and
enzymes.
Seminal plasma + Sperms → Semen

19. 3. ACCESSORY GLANDS
MALE REPRODUCTIVE
SYSTEM
Functions of seminal plasma:
❑ Helps for transporting sperms.
❑ Supplies nutrients to sperms.
❑ Provides alkalinity to counteract acidity of
uterus.
❑ Secretions of Cowper’s glands lubricate the
penis.
Secretions of epididymis, vas deferens,
seminal vesicle & prostate help for
maturation and motility of sperms.

21. 4. PENIS (EXTERNAL GENITALIA)
MALE REPRODUCTIVE
SYSTEM
• It is a copulatory organ.
• It is made up of special erectile
spongy tissues.
• When spongy tissue is filled with
blood, the penis erects. It
facilitates insemination.
• The cone-shaped tip of the penis
is called glans penis. It is covered
by prepuce (foreskin).

22. Penis
The penis has a root and a body. The root lies in the perineum and
the body surrounds the urethra. It is formed by three cylindrical
masses of erectile tissue and involuntary muscle. The erectile tissue
is supported by fibrous tissue and covered with skin and has a rich
blood supply.
The two lateral columns are called the corpora cavernosa and the
column between them, containing the urethra, is the corpus
spongiosum. At its tip it is expanded into a triangular structure
known as the glans penis. Just above the glans the skin is folded
upon itself and forms a movable double layer, the foreskin or
prepuce. Arterial blood is supplied by deep, dorsal and bulbar
arteries of the penis which are branches from the internal pudendal
arteries.
A series of veins drain blood to the internal pudendal and internal
iliac veins. The penis is supplied by autonomic and somatic nerves.
Parasympathetic stimulation leads to filling of the spongy erectile
tissue with blood, caused by arteriolar dilatation and
venoconstriction, which increases blood flow into the penis and
obstructs outflow. The penis therefore becomes engorged and
erect, an essential prerequisite for coitus to occur.

23. FEMALE
REPRODUCTIVE
SYSTEM

24. The female reproductive system
includes external and internal
genitalia.
The vulva and its structures form the
external genitalia.
The internal genitalia include a
three-part system of ducts: the
uterine tubes, the uterus, and the
vagina.
This system of ducts connects to the
ovaries, the primary reproductive
organs.
The ovaries produce egg cells and
release them for fertilization.
Fertilized eggs develop inside the
uterus.

25. Femal
e
reprod
uctive
system
Paired
ovaries
Accessory
ducts
Oviducts (Fallopian
tube)-2
Uterus
Vagina
External
genitalia
Mons pubis
Vestibule
Hymen
Clitoris
FEMALE REPRODUCTIVE HEALTH

26. External genitalia (vulva)
The external genitalia are known collectively as the vulva, and
consist of the labia majora and labia minora, the clitoris, the vaginal
orifice, the vestibule, the hymen and the vestibular glands
(Bartholin's glands).
Labia majora
These are the two large folds which form the boundary of the vulva.
They are composed of skin, fibrous tissue and fat and contain large
numbers of sebaceous glands. Anteriorly the folds join in front of the
symphysis pubis, and posteriorly they merge with the skin of the
perineum. At puberty hair grows on the mons pubis and on the lateral
surfaces of the labia majora.
Labia minora
These are two smaller folds of skin between the labia majora,
containing numerous sebaceous glands. The cleft between the labia
minora is the vestibule. The vagina, urethra and ducts of the greater
vestibular glands open into the vestibule.
Clitoris
The clitoris corresponds to the penis in the male and contains sensory
nerve endings and erectile tissue but it has no reproductive
significance.

27. Hymen
The hymen is a thin layer of mucous membrane
which partially occludes the opening of the vagina. It
is normally incomplete to allow for passage of
menstrual flow.
Vestibular glands
The vestibular glands (Bartholin's glands) are situated one
on each side near the vaginal opening. They are about the
size of a small pea and have ducts, opening into the
vestibule immediately lateral to the attachment of the
hymen. They secrete mucus that keeps the vulva moist.
Internal genitalia
The internal organs of the female reproductive system lie in the pelvic cavity
and consist of the vagina, uterus, two uterine tubes and two ovaries.
Vagina
The vagina is a fibromuscular tube lined with stratified squamous epithelium, connecting the external and internal organs of reproduction. It runs
obliquely upwards and backwards at an angle of about 45° between the bladder in front and rectum and anus behind. In the adult the anterior wall
is about 7.5 cm (3 inches) long and the posterior wall about 9 cm long. The difference is due to the angle of insertion of the cervix through the
anterior wall.
Purposes of the Vagina
• Receives a males erect penis and semen during sexual intercourse.
• Pathway through a woman's body for the baby to take during childbirth.
• Provides the route for the menstrual blood (menses) from the uterus, to leave the body.
• May hold forms of birth control, such as a diaphragm, FemCap, Nuva Ring, or female condom.

28. Uterus
The uterus is a hollow muscular pear-shaped organ,
flattened anteroposteriorly. It lies in the pelvic cavity
between the urinary bladder and the rectum. In most
women, it leans forward (anteversiori), and is bent
forward (anteflexiori) almost at right angles to the
vagina, so that its anterior wall rests partly against the
bladder below, and forming the vesicouterine pouch
between the two organs.
The fundus. This is the dome-shaped part of the
uterus above the openings of the uterine tubes.
The body. This is the main part. It is narrowest
inferiorly at the internal os where it is continuous
with the cervix.
The cervix ('neck' of the uterus). This protrudes
through the anterior wall of the vagina, opening into
it at the external openings.

29. Uterine tubes (Fallopian tubes)
The uterine tubes are about 10 cm long and
extend from the sides of the uterus between the body and
the fundus. They lie in the upper free border of the broad
ligament and their trumpet-shaped lateral ends penetrate
the posterior wall, opening into the peritoneal cavity close
to the ovaries. The end of each tube has fingerlike
projections called fimbriae. The longest of these is the
ovarian fimbria which is in close association with the
ovary.
The uterine tubes have an outer covering of
peritoneum (broad ligament), a middle layer of smooth
muscle and are lined with ciliated epithelium.
Ovaries
The ovaries are the female gonads, or glands, and they lie in a
shallow fossa on the lateral walls of the pelvis. They are 2.5 to
3.5 cm long, 2 cm wide and 1 cm thick. Each is attached to the
upper part of the uterus by the ovarian ligament and to the back
of the broad ligament by a broad band of tissue, the mesovarium.
Blood vessels and nerves pass to the ovary through the
mesovarium

30. Puberty in the female
Puberty is the age at which the internal reproductive organs
reach maturity. This is called the menarche, and marks the
beginning of the childbearing period. The ovaries are stimulated
by the gonadotrophins from the anterior pituitary, follicle
stimulating hormone and luteinising hormone.
The age of puberty varies between 10 and 14 years and
a number of physical and psychological changes take place at
this time:
• the uterus, the uterine tubes and the ovaries reach maturity
• the menstrual cycle and ovulation begin (menarche)
• the breasts develop and enlarge
• pubic and axillary hair begins to grow
• there is an increase in the rate of growth in height and
widening of the pelvis
• there is an increase in the amount of fat deposited in the
subcutaneous tissue, especially at the hips and breasts.

31. Breasts or mammary glands
The breasts or mammary glands are accessory glands of the
female reproductive system. They exist also in the male but in
only a rudimentary form. In the female the breasts are small and
immature until puberty. Thereafter they grow and develop to
their mature size under the influence of oestrogen and
progesterone.
During pregnancy these hormones stimulate further growth.
After the baby is born the hormone prolactin from the anterior
pituitary stimulates the production of milk, and oxytocin from
the posterior pituitary stimulates the release of milk in response
to the stimulation of the nipple by the sucking baby, by a
positive feedback mechanism.
The mammary glands are only active during late pregnancy and
after the birth of a baby when they produce milk (lactation).
Lactation is stimulated by the hormone prolactin

32. STRUCTURE LOCATION & DESCRIPTION FUNCTION
Breasts Upper chest one on each side containing
alveolar
cells (milk production), myoepithelial
cells
(contract to expel milk), and duct walls
(help with extraction of milk).
Lactation milk/nutrition for newborn.
Cervix The lower narrower portion of the
uterus.
During childbirth, contractions of the
uterus will dilate the cervix up to 10
cm in diameter to allow the child to pass
through. During orgasm, the cervix
convulses and the external os dilates
Clitoris Small erectile organ directly in front of
the
vestibule.
Sexual excitation, engorged with blood.
Fallopian tubes Extending upper part of the uterus on
either side.
Egg transportation from ovary to uterus
(fertilization usually takes place
here).
Hymen Thin membrane that partially covers the
vagina in young females.

34. The Female Reproductive Cycle /The menstrual (sexual) cycle
The female menstrual cycle begins during puberty (between the ages of 10-13 years). It is characterized by changes in
the endometrium of the uterus. The first menstrual cycle is called menarche.
This is a series of events, occurring regularly in females every 26 to 30 days throughout the childbearing period of
about 43 years. The cycle consists of a series of changes that take place concurrently in the ovaries and uterine walls,
stimulated by changes in the blood concentrations of hormones. Hormones secreted in the cycle are regulated by
negative feedback mechanisms.
The hypothalamus secretes luteinising hormone releasing hormone (LHRH) which stimulates the anterior pituitary to
secrete:
• follicle stimulating hormone (FSH), which promotes the maturation of ovarian follicles and the secretion of
oestrogen, leading to ovulation
• luteinising hormone (LH), which triggers ovulation, stimulates the development of the corpus luteum and the
secretion of progesterone.
The hypothalamus responds to changes in the blood levels of oestrogen and progesterone. It is switched off by high
levels and stimulated when they are low.
The average length of the menstrual cycle is about 28 days. By convention the days of the cycle are numbered from
the beginning of the menstrual phase of the menstrual cycle which usually lasts about 4 days. This is followed by the
proliferative phase (about 10 days), then by the secretory phase (about 14 days).
The ranges of normal menstrual cycles are as follows:
• Cycle length: 21 to 36 days
• Duration of flow: 3 to 7 days
• Amount of flow: 20 to 80 mL

35. The menstrual cycle is under the control of three sets of hormones:
❑ Gonadotrophin releasing hormones
❑ Gonadotrophins - luteinising hormone (LH) and follicle stimulating hormone (FSH) from the
pituitary gland
❑ Ovarian hormones - oestrogen and progesterone
The menstrual cycle can be divided into three phases:
The follicular phase
FSH stimulates the development of several follicles in the ovary, usually only one of these follicles
matures. This dominant follicle produces oestrogen, which causes the endometrium to start to thicken.
It also causes the mucus in the cervix to become thinner and more stretchy, allowing sperm to reach the
egg more easily.
Ovulation
Oestrogen levels that have been gradually increasing, peak. The LH levels increase rapidly (day 12
onwards) triggering the release of the egg from the ripened follicle, which usually occurs 36 hours after
the onset of the LH surge.
The luteal phase
The levels of FSH and LH decrease. The ruptured follicle closes (after releasing the egg) and forms a
corpus luteum, which produces progesterone. This prepares the endometrium even further, ensuring it is
spongy, thick and full of nutrients so that a fertilised egg can implant into it. If the egg is not fertilised
the corpus luteum starts to degenerate and progesterone and oestrogen levels start to fall.

37. The reproductive cycle can be divided into an ovarian cycle and a
uterine cycle (compare ovarian histology and uterine histology in the
diagram on the right). During the uterine cycle, the endometrial
lining of the uterus builds up under the influence of increasing levels
of estrogen (labeled as estradiol in the image). Follicles develop, and
within a few days one matures into an ovum, or egg. The ovary then
releases this egg, at the time of ovulation. After ovulation the uterine
lining enters a secretory phase, or the ovarian cycle, in preparation
for implantation, under the influence of progesterone. Progesterone is
produced by the corpus luteum (the follicle after ovulation) and
enriches the uterus with a thick lining of blood vessels and capillaries
so that it can sustain the growing fetus. If fertilization and
implantation occur, the embryo produces Human Chorionic
Gonadotropin (HCG), which maintains the corpus luteum and causes
it to continue producing progesterone until the placenta can take over
production of progesterone. Hence, progesterone is "pro gestational"
and maintains the uterine lining during all of pregnancy. If
fertilization and implantation do not occur the corpus luteum
degenerates into a corpus albicans, and progesterone levels fall. This
fall in progesterone levels cause the endometrium lining to break
down and sluff off through the vagina. This is called menstruation,
which marks the low point for estrogen activity and is the starting
point of a new cycle.

38. Common usage refers to menstruation and menses as a period. This bleeding serves as a sign that a woman has not
become pregnant. However, this cannot be taken as certainty, as sometimes there is some bleeding in early pregnancy.
During the reproductive years, failure to menstruate may provide the first indication to a woman that she may have
become pregnant.
Signs of ovulation
The female body produces outward signs that can be easily recognized at the time of ovulation. The two main signs are thinning of
the cervical mucus and a slight change in body temperature.
Thinning of the Cervical Mucus
After menstruation and right before ovulation, a woman will experience an increase of cervical mucus. At first, it will be thick and
yellowish in color and will not be very plentiful. Leading up to ovulation, it will become thinner and clearer. On or around the day
of ovulation, the cervical mucus will be very thin, clear and stretchy. It can be compared to the consistency of egg whites. This
appearance is known as 'spinnbarkeit’.
Temperature Change
A woman can also tell the time of ovulation by taking her basal body temperature daily. This is a temperature taken
with a very sensitive thermometer first thing in the morning before the woman gets out of bed. The temperature is
then tracked to show changes. In the uterine cycle, a normal temperature will be around 97.0 – 98.0. The day of
ovulation the temperature spikes down, usually into the 96.0 – 97.0 range and then the next morning it will spike up
to normal of around 98.6 and stay in that range until menstruation begins.
Both of these methods are used for conception and contraception. They are more efficient in conception due to the
fact that sperm can live for two to three days inside of the fallopian tubes. A woman could be off by a couple of days
in her calculations and still become pregnant.