Embryology 1 - Overview and Teratology Flashcards
When is the Embryonic Period?
fertilization –> second month of gestation
When is the Fetal Period?
Second month of gestation –> full term
What is the Obstetric (gestational ) age?
Begins at last menstrual period
What is the Embryonic age?
Begins at time of fertilization
What is Fertilization?
- Initiation of embryo development
- Occurs when an oocyte and sperm merge
During 1st week, embryo is ____
Preparing for implantation
Within 2 days of fertilization, a ______ has formed.
Zona pellucida
At around 5 days, a ____ hatches out of the zona pellucida
Blastocyst
During 2nd-3rd weeks, embryo is _____.
Setting up basic body plan
At around 6-7 days, _____ occurs
Implantation
At around 16 days, the embryo develops _______ and is ___ long.
Primitive streak at the caudal end; 1 mm
At around 22 days, the embryo develops _____ and is __ long.
Somites (body segmentation); 2.5mm
During the 4th-8th weeks, the embryo is ______.
Making precursors of major organs.
During the 4th week, the embryo has developed _____ and is ___ long.
4 mm.
During the 5th week, the embryo has developed ____.