This is a presentation about human reproduction, it entails how the process of fertilization occurs and how different hormones work together to make sure the process of fertilization occurs. it further explains the development of an embryo up until adulthood.
26. Primordial germ cell in embryo
Mitotic divisions
Spermatogonial
stem cell
Mitotic divisions
Spermatogonium
Mitotic divisions
Primary spermatocyte
Meiosis I
Secondary spermatocyte
Meiosis II
Early
spermatid
Differentiation (Sertoli
cells provide nutrients)
Sperm
2n
2n
2n
n n
n n n n
n n n n
SPERMATO
-
GENESIS
30. Fig. 46-12g
Primordial germ cell
Mitotic divisions
Oogonium
Mitotic divisions
Primary oocyte
(present at birth), arrested
in prophase of meiosis I
Completion of meiosis I
and onset of meiosis II
Secondary oocyte,
arrested at metaphase of
meiosis II
First
polar
body
Ovulation, sperm entry
Completion of meiosis II
Second
polar
body
Fertilized egg
2n
2n
n
n
n
n
In embryo
OOGENISIS
49. Ovary
Uterus
Endometrium(a) From ovulation to implantation
(b) Implantation of blastocyst
Cleavage
Fertilization
Ovulation
Cleavage
continues
The blastocyst
implants
Trophoblast
Inner cell mass
Cavity
Blastocyst
Endo-
metrium
1
2
3
4
5
Formation of the zygote and early
post-fertilization events
60. Fig. 46-18
Estradiol Oxytocin
from
ovaries
Induces oxytocin
receptors on uterus
from fetus
and mother’s
posterior pituitary
Stimulates uterus
to contract
Stimulates
placenta to make
Prostaglandins
Stimulate more
contractions
of uterus
Positivefeedback
+
+
A model for the induction of
labour