Reproduction
in Humans
Asexual reproduction in animals
1- Budding —> cells in the body wall divide to form
a small version of the adult
2- Binary fission —> Bacteria grows large and split
into two identical daughter cells
It depends on mitosis to provide genetically identical cell
Sexual reproduction
Two parents
Meiosis
Haploid
gametes
Fertilisation
Diploid
zygote
Mitosis
To increase
the no. Cell
Female reproductive organ
enipoten -
sta
y
Uterus lining
Ovary —> 1- production of female gametes ( egg cell or Ovum ) (Meiosis)
—> 2- release Oestrogen Hormone ( 2ry sex characteristics)
—> 3- Site of formation of corpus luteum (releases progesterone)
Oviduct ( fallopian tube ) —> Site of Fertilisation (1st third of the oviduct )
—> It has cilliated cells that push the fertilized
egg cell to be implanted in the uterus
Uterus lining —> where implantation of fertilized egg cell/ ovum takes place
—> placenta depvelopes
Muscular wall —> contracts during delivery to help push the fetus out of
the uterus
Uterus —> where the embryo developes
Cervix —> ring of muscles that contract to hold the fetus during
pregnancy and relaxes during delivery
Vagina —> connective / elastic tissue —> to receive the sperm
—> stretches during delivery
Male reproductive organ
Side view
Front view
Testis —> site of male gamete formation ( sperm) by meiosis division
—> site of production of testosterone hormone (2ry sex characters)
Epididymis —> store the sperm
Scrotum sac —> Holds the testes outside the body to provide optimum
Tempertaure for sperm production and storage
Sperm duct or vas difference —> carries the sperm to the urethra
Seminal vesicles / Prostate gland —> releases a fluid
It provides a liquid medium for the movement of the sperm
It nourishes the sperm ( glucose for aerobic respiration and ATP for
swimming )
It neutralizes the .pH of the urethra so its optimum for the sperm
Urethra —> its a common opening for semen and urine
Penis that has erectile tissue to be able to enter the Vagina and ejaculate
and release semen in the vagina
Steps of Fertilisation
Structure of the sperm Structure of the ovum
Acrosome Jelly coat hardens after
Fertilisation to ensure
that only one sperm
penetrates the ovum
Site of aerobic
respiration Full of protein
and
carbohydrates
Smaller in size Larger in size
Mobile /Motile Immobile
Millions of sperm Less in number
Internal Fertilisation
1-Penis is inserted in the vagina during sexual intercourse and ejaculate
2- Release the semen in the vagina
3- Sperm starts to swim till reach the 1st third of the oviduct
4- sperm release digestive enzyme from the acrosome that help
penetrate the ovum membrane
5- Fusion between the male gamete haploid nucleus with the female
gamete haploid nucleus to form a diploid zygote
6- the jelly coat hardens preventing the enterance of another sperm
7- Zygote starts to divide by mitosis to become a ball of cells
8- the ball of cells gets pushed by the cilia in the oviduct
9- to be implanted in the uterus wall
10- Placenta / umbilical cord and amniotic sac starts to form
Placenta , umbilical cord and amniotic sac
Umbilical cord Amniotic Sac
Connects between Secrete Amniotic
the fetus and fluid
placenta 1- Protects the baby
• Umbilical artery against mechanical
• Umbilical vein shocks
2- Free movement of
fetus
3- Sterile - Optimum
Placenta Temperature
1- Site of exchange of nutrient
and gases between the fetal
blood and maternal blood by
diffusion
( fetal gets glucose , oxygen
and amino acid and delivers
waste as Co2 and urea to
maternal blood)
2- No mixing takes place
between maternal and fetal
blood
A- to protect the fetus
against the maternal pressure What’s the importance of the presence of
B- to protect the fetus microvilli in the placenta ?
against the mothers immunity Increase the surface area for exchange
3- Release progesterone that between maternal and fetal blood
maintains pregnancy as it
maintains uterus lining
thickness and vascularity
4- Site of physical attachement
to the uterus wall
Delivery
• Embryo has fully grown into fetus
• At the end of the nine month its starts to send a hormonal
signal to mother to begin the birth process
Cervix dilate Vagina stretch Cut the umbilical
Muscular wall of Baby pass out head cord and tie it
uterus contacts first through vaginal Placenta is expelled
Amniotic sac rupture through the vagina
Amniotic fluid is Afterbirth
release
Puberty these changes that are controlled by hormones that
indicates sexual maturity
Menstrual cycle Pituitary gland
Brain.
FSH LH
Follicle stimulating hormone Lutenising hormone
Ovulation → release of mature
Stimulate The formation and
growth of a follicle inside ovum from the follicle inside the
The ovary ovary. The follicle becomes
corpus luteum
Ovary
OEstrogen Progesterone
Increase the vascularity and Completes the development of
thickness of uterus lining and uterus lining and maintain it.
it inhibit the release of FSH it Inhibit the release of FSH and LH
stimulate the release of LH
Ovum in the oviduct
High level of progesterone
Ovum gets fertilized by a sperm Ovum is not fertilized
Zygote formed Corpus luteum degenerate
Divide Progesterone level starts
to drops
Implanted in uterus lining
Uterus lining starts to shed
9 month of pregnancy
Bleeding takes place which is
known as menstruation
Progesterone
What is the first step in menstrual cycle?
Menstruation / period → release of menstrual blood and cells of lining
Timing
O -7 → menstruation / release of FSH
7-14 → 8estrogen is released & increase thickness of uterus lining
14 → LH released and ovulation takes place
14-21 → fertility window progesterone gets released
24- 28 → progesterone levels starts to drops
Sperm gets deposited into vagina at day 13 of menstrual cycle while
pregnancy be achieved.
Yes, sperm can survive for 48 hours inside the female reproductive
organ
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