Flashcards in Embryology Deck (22):
Average Fetal age from conception to birth
Average Gestational age from conception to birth
During what period are all major organs formed?
embryonic (first 8 weeks)
During what period do all organs grow larger and become more complex?
fetal (last 30 weeks)
egg released into the peritoneal cavity
occurs as egg travels down fallopian tube and meets sperm
the cell that forms when the ova and sperm fuse
begins immediately as the zygote travels down the fallopian tube & into the uterus
the solid cluster of 12-16 blastomeres at about 72 hours
On day 4 post conception, what does the 60 cell morula become when it enters the uterus and takes up fluid?
type of cell in blastocyst stage that forms the embryo
inner cell mass
layer of cells surrounding the cavity which helps form the placenta
What happens if inner cell mass of a single blastocyst divides?
monozygotic (identical) twins
two fluid filled sacs in the inner cell mass
Amniotic sac from epiblast
Yolk sac from hypoblast
will become the serous cavities of the ventral body cavity
period when MOST gross structural birth defects are induced
Weeks 3-8 (Organogenesis)
When does the heart start pumping in the embryo?
29 days (one month)
When does closure of the neural tube occur?
week 3-week 4
lateral ectodermal cells, pulled along and form sensory nerve cells and other structures
Germ layer that becomes epidermis, hair, nails, glands of skin, brain, spinal cord, neural crest
Germ layer that becomes intervertebral discs, trunk and limb musculature, vertebrae, ribs, kidneys, gonads, connective tissue, heart, blood vessels