Embryology and Fetal Development Flashcards
Define what an embryo is
From implantation until 8 weeks of development
What occurs in the first 0-4 weeks of embryogenesis
Rapid growth;
Embryonic plate forms which creates the CNS;
Heart develops and starts to beat;
Limb buds form
What occurs during weeks 5-8 of pregnancy to the embryo
Rapid cell division;
Head and facial features form;
Major organs are laid down in their primitive forms;
External genitalia develops but gender is not distinguishable;
Early movements;
Visible on ultrasound scan from week 6
Define Chorion
The outer of 2 membranes enclosing the fetus in utero
Define what happens to the growth of the fetus during weeks 8-12
- Head = 1/2 of fetal length
- Teeth form in the gyms
- Intestines become established
- Blood begins to form
Define lanugo
Fine hair covering the fetus, usually disappears by term or shortly after birth
Define vernix (caseosa)
Greasy substance covering the fetus in utero
Appears during 30-32 weeks and remains until, or past full term
What developments occur during weeks 13-16 to the fetus?
Rapid muscle and bone growth
Facial features adopt the correct position
Meconium forms in the gut
During weeks 17-24, how does the fetus develop
Vernix appears;
Fetal heart heard
Movements can be felt
Lungs are well formed
Development with the fetus changes between weeks 25-26, how?
QSubcutaneous fat laid down
Eyes can now open
Lungs are sufficiently developed
Nervous system can now control breathing and temperature
Define how the fetus further develops during weeks 29+
Fetus is fully formed
Organs are now able to function to some extent
Define Amenorrhoea
The absence of menstruation in post-pubertal women
Define conceptus
A fertilised ovum from uniting gametes
