Fetal Development Flashcards
What is an acrosome?
Develops during maturation of the sperm. It contains digestive enzymes that help sperm across the corona radiata.
What is capacitation?
Process that sperm goes through in crypts of female genital tract where it is fed and prepared to make it responsive to female environment.
The ovum is surrounded by what 2 walls?
Corona Radiata and Zona Pellucida.
What is Cortical Reaction?
When the Zona Pellucida blocks enzymes of any other sperm, preventing them from attaching.
What is the pre-embryonic stage?
From fertilisation to implantation.
What is the embryonic stage?
From implantation to week 8.
What is the fetal stage?
From week 9 to birth.
What 4 steps is the pre-embryonic stage made up of?
Zygote - Day 2 Embryo (cleavage) - Morula (3 days) - Blastocyst (10 days)
What is the bilaminar disc?
The embryoblast differentiates into two layers when implantation occurs; the epiblast and hypoblast.
What is Gastrulation?
The process of the bilaminar disc evolving into a trilaminar disc. It puts an end to the pre-embryonic state (at day 15).
What does the epiblast differentiate into during gastrulation?
Ectoderm. This forms skin, hair, nails etc.
What does the hypoblast differentiate into during gastrulation?
Endoderm. This forms glandular cells and lining of digestive and respiratory tracts.
What is the Primitive Streak?
A channel created by epiblast cells migrating inwards. More cells migrate through it between the 2 layers of bilaminar disc, forming the mesoderm layer.
What does the Mesoderm form?
Muscles, bones, blood and urogenital glands.
What is the notochordal process?
The creation of a tube that in the mesoderm by the ectoderm. It temporarily connects the amniotic cavity and yolk sac, providing pressure equilibrium.
