Intro to Embryology Flashcards
The entire products of conception from fertilization onward
conceptus
Cell formed by the union of an oocyte and a sperm
zygote
Mitotic division of zygote forming embryonic cells called blastomeres
cleavage
Female germ or sex cell produced in the ovaries
oocyte/ovum
The time period since fertilization
fertilization age
The expulsion of an embryo or fetus from the uterus before it is viable
abortion
The beginning or first discernible indication of an organ or structure
primordium
A ball of about 12-32 blastomeres which have cleaved to form the zygote
morula
Term applied to the developing human after 8 weeks of development
fetus
Age of embryo calculated from the first day of the last normal menstrual period
gestational age
Male germ or sex cell produced in the testes
sperm
Period consisting of 3 calendar months
trimester
Branch of science concerned with the origin and development of a human being from a zygote to birth of an infant
human embryology
Mature oocyte
secondary oocyte/ ovum
Period of time from the 9th week of development to birth
fetal period
Term meaning a fetus is mature enough to survive outside the uterus
viable
A fluid-filled cavity inside the morula
blastocystic cavity
Contains an inner cell mass that will form the embryo
embryoblast
Term referring to the embryo or fetus and its membranes
conceptus
Refers to a secondary oocyte impregnated by a sperm
fertilized ovum
Term referring to the uterine tube
fallopian tube
The developing human during the early stages of development (1-8weeks)
embryo
Specific genes that regulate early embryonic development
sonic hedgehog SHH
Age reference of the embryo using the first day of the last normal menstrual period as a reference for day 1 (2 wks more than fert age)
LMP
Period of development from the 1st to 8th week
embryonic period
Most critical stages of development
first trimester
Term referring to the ability of human embryonic stem cells having the capacity to develop into diverse cell types
pluripotential
What do a secondary oocyte and sperm form to create
zygote
It is estimated that over _____ of all fertilized ova are spontaneously aborted
50%
______% of live born infants have a major birth defect
4-6%
Most of the insults that cause defects occur in the _______ after fertilization when basic cell development is taking place
1st 8 weeks
Chemicals secreted by embryonic cells determine which genes get activated and therefore, what grows where
molecular signals
Proteins that bind to DNA and regulate the expression of genes downstream from the binding site
transcription factors
Acts by inhibiting an inhibitor. This is a common method of regulation in embryonic development
SHH
