Principles of Medical Embryology 🗸 Flashcards
Gamete
Mature haploid germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote
embryonic period
weeks 3-8 in humans
teratogen
cause irreversible, deleterious structural malformations in fetuses
mutagen
causes changes in the genetic material of cells
7 stages of embryogenisis
gametogenisis
fertilisation
cleavage
gastrulation
embryonic folding
organogenesis
fetal period
gametogenisis
the formation of gametes
spermatogenesis: formation of male gamete, occurs at puberty and continues throughout life
oogenesis: formation of female gametes, primary oocytes begin meiosis by weeks 28-39, but arrest in prophase until puberty
Fertilisation
union of gametes, fusion of sperm and oocyte to form a zygote
cleavage
period of rapid mitotic cell division with no increase in size, forms morula then blastocyst (days 1-4)
Gastrulation
Formation of the germ layers, ectoderm, mesoderm and endoderm, the body axis is established
Embryonic folding
formation of the body plan
fetal period
from week 9 until birth
growth and weight gain as tissues mature and become functional
overt sexual differentiation
bone is laid down so connections made in CNS
Six primary processes of embryonic development
Cell division
differentiation
cell attachment
apoptosis
induction
cell migration
two secondary processes of embryonic development
axis formation
foliding/rotation
three factors responsible for embryonic development regulation
genetic
epigenetic
environmental influences
