Medical knowledge | Embryology » Dr. Réthelyi Miklós - Embryology

EMBRYOLOGY GERM CELLS, FERTILIZATION, CLEAVAGE, IMPLANTATION Dr. Miklós Réthelyi ANATOMY HISTOLOGY EMBRYOLOGY Shape Processes How does it look? Increase and differentiation of the cells 1 cell 2 cells 4 cells and so on Embryoblast cells Zygote Morula Trophoblast cells Primordial germ cells body fetal membranes GONADS EMBRYONIC DISC IMPLANTATION GAMETOGENESIS Formation and differentiation of the germ cells (gametes) Germ cells Spermatozoon (Sperm) Mitosis Oocyte (Ovum) Meiosis Doubling of the chromatids chromosomes 1 chromosome = 2 chromatids No doubling Homologue chromosomes align in pairs Rearrangement (Crossing over) MITOSIS MEIOSE Chromatids 4 chromatides 2 chromatides 1 chromatide First meiotic division Second meiotic division SPERMATOGENESIS TESTIS OOGENESIS OVARY Seminiferous tubule Lining: Sertoli cells Seminiferous tubule Spermatogonia Mitotic division A Spermatogonia (further mitosis) B Spermatogonia

(differentiation and growth) Primary spermatocyte SPERMATOGENESIS TESTIS OOGENESIS OVARY Seminiferous tubule Primary spermatocyte First meiotic division Secondary spermatocyte SPERMATOGENESIS TESTIS OOGENESIS OVARY Seminiferous tubule Secondary spermatocyte Second meiotic division Spermatids SPERMATOGENESIS TESTIS OOGENESIS OVARY Seminiferous tubule Sperms Spermiogenesis Spermatids SPERMATOGENESIS TESTIS OOGENESIS OVARY Spermiogenese (Spermiohistogenese) Spermatid Spermium SPERMATOGENESIS TESTIS OOGENESIS OVARY OVARY Primary oocyte (Oogonium) Cumulus oophorus Tertiary follicle Ovulation Oocyte Corona radiata Zona pellucida Spermiogenesis Oogenesis Proliferation after puberty before birth Enlargement after puberty after puberty First meiotic division after puberty before birth – dictyotene stadium (rest phase) Primordial germ cell : mature germ cell 1:4 1 : 1 und 3 polocytes Maturation

continuous periodic Special maturation spermiohistogenesis - Sex chromosomes 2 sperms with Y (Androspermium), 2 sperms with X (Gynospermium) all oocytes with X Motility of the mature germ cells + - FERTILIZATION Capacitation Acrosome reaction Acrosin FERTILIZATION ZYGOTE CLEAVAGE MORULA BLASTULA IMPLANTATION Endometrium Epithel Tunica propria Uterus Cell-rich connective tissue – decidua cells Glands Myometrium smooth muscles Zygote amnion epithel Morula (Blastomeres) amniotic cavity (amniotic fluid) Primordial germ cells Blastula epiblast (ectoderm) Trophoblast Syncytiotrophoblast Embryoblast (inner cell mass) Cytotrophoblast embryonic disc hypoblast (endoderm) Extraembryonic mesoderm yolk sac Chorion Placenta Heuser membrane Endometrium Endometrium Fetal membranes PLACENTA Decidua basalis Chorion frondosum + Decidua marginalis Decidua marginalis Amnion epithel Chorium leve Chorium leve Decidua capsularis

Abnormal implantation sites