3B Scientific Stages of Fertilization and of the Embryo- 2-times Magnification - Manual (Page 4)

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English
Stages of fertilisation and blastogenesis
The model provides a schematic representation to illustrate the maturation of ova, ovulation, fertilisation
and blastogenesis up until the embryo is implanted in the wall of the womb. The stages of development
can be seen in large-scale models inside the ovary, the fallopian tubes and the womb. In some cases, even
larger scale versions can be seen on the base.
Inside the ovary, primordial, primary, secondary and tertiary follicles can all be seen as well as a split terti-
ary follicle and a yellow body (corpus luteum).
In the fallopian tube near the ovary there is a recently split ovum with pellucid zone and corona radiata
(part of the follicular epithelium) (Fig. 1).
Further along in the amplulla of the uterine tube (ampulla tuba uterina), a sperm is penetrating an ova
(fertilisation) (Fig. 2)
Further along the fallopian tube a fertilised ovum (zygote) is shown with both a male and a female pronu-
cleus (Fig. 3).
The following stages of cleavage are illustrated:
• Two-cell stage (Fig. 4)
• Four-cell stage (Fig. 5)
• Segmentation spheres (morula) (Fig. 6)
In the wonb (cavitas uteri) is a four-day-old blastocyst (Fig. 7) and an embryo of about 12 days old, that is
now fully implanted into the mucous membrane of the womb (Fig. 8).
1 Uterus
2 Uterine cavity
3 Endometrium
4 Myometrium
5 Vagina
6 Corpus luteum
7 Corpus albicans
8 Primordial ovarian follicle
9 Primary ovarian follicle
10 Secondary ovarian follicle
11 Graafian follicles
12 Ovary
13 Graafian follicle
14 Ovulation
15 Fertilisation
16 Spermatazoa
17 Ovum with pronuclei
18 Two-cell stage
19 Four-cell stage
20 Uterine tube 21 Morula
22 Blastocyst
23 Implanted embryo
24 Split ovum
25 Corona radiata
26 Pellucid zone
27 Ovum
28 Polar bodies
29 Blastomere (segmentation sphere,
cleavage cell)
30 Trophoblast
31 Cleavage, segmentation or subgerminal cavity
32 Embryoblast (inner cell mass)
33 Reflex decidua
34 Yolk sack
35 Amniotic cavity
36 Extraembryonic mesoderm
37 Coelom