Embryology and fetal development Flashcards
Capacitation
A maturing process that’s the sperm go through once in the denial reproductive tract
Acrosome reaction
Enzymes from the acrosome digest outer layer of the ova
Ovum
From ovulation to fertilisation
Zygote
Fertilisation to implantation
Embryo
Implantation to the 8th week
Fetus
From 8 weeks until term
Fertilisation
The union of an oocyte and a sperm (conception)
Where does fertilisation take place
Fallopian tube
What does oestrogen cause that helps sperm cells be able to swim?
Thinning of uterine secretions
What stimulates flagella for swimming?
Prostaglandins
What prevents addition of more sperm cells into the secondary oocyte after one sperm cell has penetrated?
Changes to the egg cell membrane and zone pellucida
First trimester
1-12 weeks
Second trimester
13-27 weeks
Third trimester
28 weeks-birth
Period of mitosis when cells get smaller and smaller
Cleavage
Dividing solid mass of cells
Morula
When the morula hollows what is formed?
A blastocyst
What does the blastocyst do?
Implants into the endometrium
Blastocyst
A hollow sphere of cells that used to be a morula
When do cells of morula/blastocyst stop being pluripotent
When the blastocyst implants on the uterus
Totipotent
Cells can form all cells in the body including placental or embryonic cells
Pluripotent
Cells that can give rise to any cell types in the body (no embryonic/placental)
The cells of the blastocyst have two potential purposes
- Some become the placenta
- Others become the inner cell mass that gives rise to the embryo
Outer cell wall of the blastocyst
Trophoblast
Cells of the trophoblast
Trophoblastic cells
What happens where the trophoblastic cells touch the endometrium of the uterus?
They undergo DNA synthesis and change shape to cuboid
What happens to trophoblastic cells after DNA synthesis
They form the cytotrophoblast
Cytotrophoblast
Inner layer of the trophoblast
What do the daughter cells from trophoblast Mitosis form?
A syncytium
(Mass of tissue with a protoplasm, nuclei and a syncytiotrophoblast
Syncytiotrophoblast
Outer layer of the trophoblast
What does the endometrium of the uterus becomes what after a syncytium is formed?
Decidua
What is formed inside the blastocyst?
Inner cells mass
What do the cells of the inner cell mass divide into?
Embryonic disc