Medilog

Development of Inner Cell Mass Development of inner cell mass differentiated into; 1. Amnion layer of embryo cell 2. Umbilical cord 3. Foetus After implantation, 2 cavity appear in inner cell mass. 1. Amniotic cavity/ amniotic sac contains amniotic fluid Amnion membrane forming fluid filled cavity (amniotic sac that enclose the embryo). 2. Yolk sac Before placenta form, yolk cell provide nutrition and gas exchange between mother and developing embryo.

Read More

Chorion and Chorionic Villi Chorion is outermost fetal membrane around embryo. After implantation trophoblast differentiated into;  1. Outer layer Syncytitrophoblast 2. Inner layer Cytotrophoblast (Langhan’s layer) Chorion layer made up of trophoblast and mesoderm. Chorion villi surround developing ovum. Villi overlying decidua basalis continue to grow and expand called chorion frondosum and form placenta. Mesodermal tissue (connecting stalk) connects inner cell mass to chorion and will form umbilical cord later on.

Read More

 Embryonic development After zygote formation, mitotic devision of zygote producing two blastomere. 16 cell stage called morula (solid mass of blastomere). Morula Two cell stage (called morula) reached approximately 30 hours after fertilization. Each blastomere; equal cytoplasmic and chromosome number. Morula after spending about 3 days in uterine tube enters uterine cavity through narrow uterine ostium on 4th day in the 16-64 cell stage. Central cell of morula known inner cell mass (form embryo). Peripheral cell called outer cell mass (form protective and nutritive membranes

Read More

 Implementation Implementation stages are; Stage 1 Apposition  Stage 2 Adhesion  Stage 3 Penetration  Stage 4 Invasion 1. Apposition Pinopods; long finger like projection (microvilli) form endometrial cell surface. Endometrial fluid secreted by endometrial gland cells, pinopods absorb endometrial fluid. Endometrial fluid rich in glycogen and mucin provide nutrition to blastocyst. 2. Adhesion (Attachment) Adhesion of blastocyst to endometrium occurs through adhesion molecules like integrin, selectin and cadherin (glycoprotein). 3. Penetration and invasion Trophoblast cells of blastocyst attach to endometrial epithelium. Invasive trophoblast cells cross endometrial

Read More

 Development of Inner Cell Mass Development of inner cell mass differentiated into; 1. Amnion layer of embryo cell 2. Umbilical cord 3. Foetus After implantation, 2 cavity appear in inner cell mass. 1. Amniotic cavity/ amniotic sac contains amniotic fluid Amnion membrane forming fluid filled cavity (amniotic sac that enclose the embryo). 2. Yolk sac Before placenta form, yolk cell provide nutrition and gas exchange between mother and developing embryo. Inner Cell Mass  Inner cell mass known as embryoblast. Embryoblast development of embryo embryonic stem

Read More

 Trophoblast (Trophectoderm) Trophoblast is cell of blastocyst.  Trophoblast differentiated into; 1. Cytotrophoblast or Langhan’s layer  2. Syncytitrophoblast Local cytokines regulate invasion of the cytotrophoblast in decidua.

Read More

 Morula Two cell stage (called morula) reached approximately 30 hours after fertilization. Each blastomere; equal cytoplasmic and chromosome number. Morula after spending about 3 days in uterine tube enters uterine cavity through narrow uterine ostium on 4th day in the 16-64 cell stage. Central cell of morula known inner cell mass (form embryo). Peripheral cell called outer cell mass (form protective and nutritive membranes of embryo).

Read More

 Blastocyst On 4th and 5th day morula in uterine cavity covered by film of mucus. Fluid pass through canaliculi of zona pellucida; separate cells of morula called blastocyst. Due to blastocyst enlargement zona pellucida become stretched, thinned and gradually disappears. Lysis of zona pellucida and escape of embryo called zona hatching. Outer side of morula become trophectoderm (adhesion of blastocyst to uterine epithelialium. Inner side of morula become inner cell mass. Changes in Blastocyst Trophoblast cell adjacent to inner cell mass primarily involved in adhesion

Read More

 Chorion and Chorionic Villi Chorion is outermost fetal membrane around embryo. After implantation trophoblast differentiated into;  1. Outer layer Syncytitrophoblast 2. Inner layer Cytotrophoblast (Langhan’s layer) Chorion layer made up of trophoblast and mesoderm. Chorion villi surround developing ovum. Villi overlying decidua basalis continue to grow and expand called chorion frondosum and form placenta. Mesodermal tissue (connecting stalk) connects inner cell mass to chorion and will form umbilical cord later on. Development of Inner Cell Mass Development of inner cell mass differentiated into; 1. Amnion

Read More