Summary Notes
Week
Colouring
Rep 1
Ageing/Physiology
Rep 3
Flashcard
Introduction to Embryology
Cellular concepts include:
Communication - cell signalling
Migration
Proliferation
Differentiation
Apoptosis
Stages of Embryology
Embryology/Embryogenesis Summary Notes 1
, There are 2 main stages of embryology:
Week 1-8 = Embryonic Stage
Week 9-birth = Foetal stages
(These weeks are different to weeks of a pregnancy or weeks of gestation, where
the mother is counting back from the first day of her period)
The period from fertilization to implantation of the blastocyst into the uterus takes 2
weeks. (If egg is fertilized then the woman doesn’t menstruate.
Process of Embryogenesis
Week 1 (Bilaminar Disc Formation)
Fertilisation - ( sperm + egg = Zygote)
12-24 hr: Mitosis- The early zygote proliferate to produce a ball of cells that
make its way along the uterine tube towards the uterus
Day 3: Morula- This is a ball of cells which become compact and tightly
squashed together.
Day 5: Blastocysts- is a fluid filled space in the morula. (embryoblast and
trophoblast)
Trophoblast - They pull luminal fluid from the uterine cavity into the
center of the morula.
Day 6: Implantation Starts: By implanting, the cell grows in the cell and
interact with the uterine wall.
The blastocyst attaches to the lining of the uterus, triggering changes to
the trophoblast and uterus lining in preparation for the implantation of
the blastocyst into the uterine wall.
Embryology/Embryogenesis Summary Notes 2
, Day 7: Differentiation: The cell Mature and specialised
💡 (During cell development, cells become specialised as they move from
a multipotent stem cell type towards (to) a cell type with a particular
task.
Trophoblast specialize into :
1. Syncytiotrophoblast (invasive)
2. Cytotrophoblast
Embryoblast specialized into:
Epiblast
Hypoblast
Week 2- Choronic Cavity Formation
Embryology/Embryogenesis Summary Notes 3