FERTILIZATION:-
Fertilization is the process of fusion of the spermatozoa with the mature ovum.
TWO PURPOSE:-
(1) To start the embryonic development of the egg.
(2) To restore the chromosome number of species.
⦁ Always fertilization occurs in the ampullary parts of the uterine cavity.(Fallopion Tube)
⦁ Fertilization life spam of oocyte range 12 To 24 Hrs.
sperm range 48 To 72 Hrs.
Ovum + Sperm → Zygote
(22+x) + (22+x) (44+xx)
(22+x) + (22+y) (44+xy)
or
(23x) + (23x) → (46xx)
(23x) + (22y) (46xy)
IMPORTANTS EVENTS FOLLING FERTILIZATION:-
⦁ Fertilization (0-15 From LMP) 0 hrs
⦁ 2 cell stage (Blastomers)-30 Hrs
⦁ 4 cell stage 40-50 Hrs 2 din
⦁ 12 cell stage 72 Hrs 3 din
⦁ 16 cell stage (Morulla) - 96hrs 4 day
⦁ Enter morulla in uterine cavity 4 day
⦁ 5th day blastocyst formrtion 4 day
⦁ Zona pellucide disappear 4-5 days
⦁ Blastocyst attachment to endometrial surface 5-6 days.
⦁ Differentition of cyto end synciotrophoblast 6-7 days.
⦁ Interstitial implantation 7-9 days
⦁ Synthesis of HCG by synctiotrophoblast - 10 days
⦁ Implantation completes 10-11days
⦁ Primary villi- 13th days
⦁ Secondary villi -16th days
⦁ Tertary villi -21th days
⦁ Placenta fully established formed - 21 days
⦁ Feto- placental cirulation establishment (Fetal Heart)- 21-22days
⦁ Internal gonards formed -8 weeks
⦁ Swallowing start - 10-12 weeks
⦁ External genital formed-12 weeks
⦁ Urine formation -12 weeks
⦁ Breathing movement- 11 weeks
⦁ Bleeding during implantation in uterus – heartman’s sign
Either way the teacher or student will get the solution to the problem within 24 hours.