Embryology Flashcards
Where does fertilisation occur?
In the uterine tube= day 0
What is formed at fertilisation?
A zygote (from the fusion of sperm+egg)
What is formed after day 3/4 of cleavage?
A morula
What does the morula turn into?
By day 5 a blastocyst is formed with a trophoblast and central cavity
When does implantation occur?
Day 11 or 12
What are the layers 2 the bilaminar disc? What are the two cavities?
Inner cell mass differentiates into epiblast and hypoblast Amniotic cavity (associated with epiblast) Yolk sac (associated with hypoblast)
What happens in week three?
Gastrulation- formation of the 3 germ layers- mesoderm, endoderm and ectoderm
What does the ectoderm give rise to?
Skin and nervous tissue
What does the endoderm give rise to?
Tubular organs (respiratory tract, guy, liver)
What does the mesoderm give rise to?
Supporting tissues (muscle, bone, CT, blood, kidneys)
What does the mesoderm give rise to?
Supporting tissues (muscle, bone, CT, blood, kidneys)
Name the different types of ossification
Endochondral Intramembranous (dermal and perichondral)
Where does dermal intramembranous ossification occur?
In the flat bones of the skull
Where does perichondral IM ossification occur?
It initiates endochondral ossification, forms a bony collar
Where does perichondral IM ossification occur?
It initiates endochondral ossification, forms a bony collar
