Human Reproductive system Male & Female reproductive system, associated organs and their functions

2. Reproductive system
• It is a natural phenomenon by which organism reproduce young ones
of their own kinds for continuation of race.
• Human beings are unisexual or dioecious i.e. male and female
reproductive system is separated in separate individual.

3. Male reproductive organs
1. Testes (one pair)
2. Epididymis (one pair)
3. Vasa deferens (one pair)
4. Ejaculatory duct (one pair)
5. Urethra.
6. Penis.
7. Accessory glands
[Seminal vesicles, prostate gland,
cowper’s gland]
UrethraPenis

4. i. Testes:
• pinkish-oval, lie inside the scrotum (scrotal sac).
• scrotum lies outside the abdominal cavity so that temperature of testes remains 20c-30c below than temperature of
body which is essential to produces sperm.
Microscopic structure:
• There are three layers to cover testes.
• These are Outer-tunica vaginalis, Middle-tunica albugania and Inner-tunica vasculosa.

5. • There are 200-300 testicular lobules in testis.
• Each lobule is composed of 1 to 4 coiled
seminiferous tubules.
• Each seminiferous tubule is of 75 cm. seminiferous
tubules opens into tubuli recti which forms small
tubules called rete testis.
• These tubules of rete ends into 12-20 ducts called
efferent ductules of vasa efferentia.
• They merge to form 6 meter long ductus deferens
which enters into the head of epididymis.
• Seminiferous tubules are lined with germinal
epithelial cells.
• These are of two types; spermatogenic cells, which
produce spermatozoa or sperms by spermatogenesis
and sertoli cells which nourishes the developing
sperms.
• In between seminiferous tubules there are connective
tissue which bears interstitial cells (cells of leydig).
• The interstitial cells produce androgens
(testosterone), which promotes development of male
accessory glands and controls male sex features
(moustache, beard, change of voice).

6. ii. Epididymis:
• It is funnel like convoluted about 6 meters long tube. Board part of anterior epididymis is called
caput epididymis.
• Middle narrow part is corpus epididymis posterior end is cauda epididymis.
• Function: store the sperm and secrets fluid to nourish sperm.
iii. Vasa deferens:
• It arises from cauda. It is 40 cm long. It forms a loop around urinary bladder and joins with duct
of seminal vesicle and forms ejaculatory duct with seminal vesicle and opens into urethra.
• Function: Carry sperm from testis to seminal vesicles.
iii. Ejaculatory duct:
• There are two short tubes of 2cm long formed by the union of duct from a seminal vesicle and
vasa deferens, there carry the mixture of sperm and secretion of seminal vesicle.
v. Urethra:
• It is 20 cm long arises from urinary bladder. It discharges both urine and semen.

7. vi. Penis:
• It is copulatory organ of human. It is
made up of three columns of spongy
tissues (two dorsal cavernosa and one
ventral corpora spongiosum).
• Enlarged-tip of penis is called glans
penis which is highly sensitive.
• Penis deposits the semen in vagina
with spermatozoa.

8. vii. Accessory glands:
a. Seminal vesicles:
• These are two pouches like below-posteriorly of urinary bladder and opens into ejaculatory duct.
• These secret a viscous fluid which keep sperms alive.
b. Prostate gland:
• It lies behind urinary bladder. It is secretes thin milky substance occupy 15-30% volume of semen.
c. Cowper’s glands:
• The paired glands lie below the prostate glands. Their alkaline secretion serves as lubricant.
Erection of penis:
• Erection is caused by dilation of blood vessel of blood vessel resulting collection of more blood spaces
of spongy tissue.
• During copulation or sexual intercourse penis releases semen on vagina called ejaculation.
• About 3ml of semen is discharged by penis in each ejaculation.
Semen :
• Composition; Sperm + secretion of seminal vesicles, prostate gland & Cowper’s gland
• PH= 7.5, 1ml of semen contains 100 millions of sperms(spermatozoa)

9. Female reproductive organs
• Female reproductive organs are,
1. Ovaries
2. Fallopian tubes (oviduct)
3. Uterus
4. Vagina
5. Vulva
6. Acessory glands [Bartholin’s
gland & mammary gland (breast)]

10. 1. Ovaries:
• There is one pair of about 2.5-3.5cm long, pink, almond shaped and situated in
abdominal cavity on either side of vertebral column.
• Each ovary is attached to upper part of uterus by an ovarian ligament.
• It is attached to dorsal body wall by mesovarium.
• Internally each ovary is differentiate with
i. Outer germinal epithelium : lined with cuboidal cells.
ii. Tunica albunginea: connective tissue below germinal epithelium.
iii. Stroma: Inner mass of connective tissues made up of cortex & medulla.
• Throughout the cortex, there are about 4,00,000 ovarian follicles which are
developed from germinal epithelial cells.
• A fully matured ovarian follicle is known as graafian follicle (also called
secondary oocyte).
• A fully matured graffian follicle has an outer sheath membrane granulosa which
encloses a follicular cavity filled with colourless fluid.
• Inside the follicular cavity an
ovum is situated. Ovum is surrounded by transparent layers- zona pellucida and
zona radiate.
• The fully matured graafian follicle releases ovum upon rupture of ovary. The
release of ovum from ovary is called ovulation.
• Then the cavity of ruptured follicle now get filled with blood clot to form corpus
luteum.
• It functions as endocrine gland which secrets a hormone called progesterone
which activates the uterus and mammary gland for their development.
• Gradually the corpus luteum reduced in size to form corpous albicans.

11. 2. Fallopian tubes (oviducts):
• These are ciliated tubes of 10-12cm long arises near the ovary and extends to uterus. It is
composed of outer serosa, middle muscularis and inner mucosa.
• A fallopian tube has four parts,
a. Funnel like infundibulum near ovary with finger like structure fimbriae
b. Wide curved part ampulla.
c. Narrow part isthmus.
d. Part near uterus (uterine).
3. Uterus:
• It is a pear shaped hollow muscular organ. It is attached to the body wall by a double
fold of peritoneum called mesometrium.
• The wall of uterus has three layers outer perimetrium, middle myometrium and inner
endometrium. Inner lining of endometrium is richely supplied with blood vessels.
• Uterus is divided into three parts, Upper dome shaped part is called fundus. Main part
is called body of uterus.
• The cavity of uterus can expand 500 times during pregnancy. Lower portion of uterus is
called cervix.

12. 4. Vagina:
• It is female copulatory organ. It is tubular,
about 10-12cm long.
• It passage for menstrual flow and receptor of
spermatozoa.
• In virgins the vaginal orifice is partially
covered by hymen membrane.
• It acts as birth canal during child birth
(partition).
5. Vulva:
• It is external genitalia it is consists of mons
pubis (hair part), clitoris (erectile organ)
labia majora (two large fold of skin which
forms the boundary of vulva) & Labia
minora (two smaller folds of skin lie
between labia majora).
• Clitoris is a small erectile organ. Labia
majora and Labia minora processes
sebaceous(oil) glands.

13. 6. Accessory glands:
• Bartholin’s glands and mammary glands.
Bartholin glands:
• These are two bean-shaped lie on either of side of
vaginal orifice.
• These glands secret viscid fluid for lubricant of
vulva during sexual intercourse and sexual
excitement.
Mammary glands:
• These are pair rounded with median nipple.
• Nipple is surrounded by a pigmented area called
arola.
• Arola has many sebaceous glands called areolar
glands.
• Each gland made up of 15-25 lobules of milky
glands.
• Each gland sends a lactiferous duct toward
nipple.
• Milk gland produce milk under the control of
prolactin and ejection of milk is controlled by
pituitary gland.

14. Menstruation (ovarian) cycle:
• It is cyclic changes occur in reproductive tract of human female on a
period of 28 days. It is confirmed by loss of vaginal blood.
• It occurs at about 13 years of age till the age of 50-55 years. The
menstruation is seen in human, monkeys, gorilla etc.
• The menstrual cycle is categorized into three phases ;Menstrual
phase, Proliferative or follicle phase & Secretory or luteal or
ovulatory phase
A. Menstrual phase; it is the phase of blood flow (weeping of uterus).
• It last for 3-5 days. It is caused due to cast off epithelia lining of
endometrium.
• Oestrogen and progesterone is very law in the blood. Menstruation is
observed only when ovum remains unfertilized.
B. Proliferative or follicle phase:
• Number of endometrium cells are rapidly proliferated. It last for 9-10
days (5th -14th ) day.
• The release of FSH from pituitary stimulates the development of
follicles of ovary.
• Ovarian follicle matured into gaafian follicle and secrete oestrogen
hormone which increases up to 12th days.
• Oestrogen enhances proliferation of cells of endometrium of uterus
and fallopian tubes (up to 2-3mm thickens).
• The wall is highly supply with blood vessels and ready for
implantation.

15. C. Secretory or luteal or ovulatory phase
• It last for about 12-14 days (14th - 28th day of menstrual
cycle).
• LH (luteinising hormone) is secreted by pituitary gland
called luteal phase.
• LH and FSH stimulate the ovulation (releases of ova). So that
LH and FSH concentration become high at this time.
• After ovulation follicles of ova (corpus luteum) secret
progesterone hormone.
• Progesterone inhabits maturation of any follicle and
ovulation.
• Progesterone stimulates thickening of endometrium for
implantation of zygote.
• It also stimulates to secret water mucus and also affects
mammary glands.
• If the ovum is not fertilized, corpus luteum starts
degenerating and the level of the hormones progesterone &
oestrogen decreases.
• At about 28th day the progesterone level falls, the blood
vessels constrict and prevent the blood supply to the
endometrium.
• It results in sheeding off the endometrium along with the
blood vessels causing menstrual phase.

17. Menopause
• It is phase of women’s life. It occurs between 50 to 55 years.
• At that age ovaries are less responsive to FSH and LH. Ovulation and
menstrual cycle becomes irregular and stop.
• After the menopause female loses the ability to reproduce
progesterone and oestrogen hormone becomes imbalance.

18. Fertilization