ch. 12 conception & fetal development Flashcards
what does healthy people 2030 recommend for childbearing women of age
daily intake of atleast 400 mcg of folic acid from fortified foods or dietary supplements
TIP: b vitamin complex prevents spina bifida in babies
where does fertilization occur in the uterus (6)
outer 1/3 of the fallopian tubes
- ovary is an extension of the uterus
- uterine fundus: top of the uterus
- endometrium: inner layer of uterus
- myometrium: middle layer of uterus
- perimetrium: outer layer of uterus
fertilization (occurs where, most fertile, survive, avg. male will deposit __ before reaching ___)
- takes place in the ampulla (out 1/3 of fallopian tubes)
- ova MOST FERTILE 12-24 hours after ovulation (sometimes releases from both ovaries which indicates TWINS)
- sperm can survive 48-72 hours
- average male will deposit 200-500 million sperm in the vagina about 1000 reaching the ampulla
embryo and fetus: pregnancy lasts how many days? embryo develops? most critical time)
280 days from first day of last menstrual period (LMP)
- embryo develops day 15 until 8 weeks after conception (2-8 weeks)
- MOST CRITICAL TIME for development of the organ systems and main external features (have to keep embryo safe during this time)
teratogens
substances or exposure that causes abnormal development
fertilization pre-fetal stages
zygote -> morula -> blastocyst -> trophoblast -> implantation (nidation) -> embryo -> fetus
zygote
fertilized ova that goes through rapid cell division
- referred to as blastomeres
morula
blastomeres form a solid ball of 12-32 cells
blastocyst (3)
(day 5-7 with implantation day 9)
- inner solid mass of cells inside a central cavity (middle layer of placenta)
- later develops into a double layer of cells (embryonic disk) from which the embryo & amnion (inner amniotic sac membrane) will develop
- AKA AMNION
trophoblast (3)
outer later of cells that surrounds the cavity
- develops into one of the embryonic amniotic membranes
- AKA CHORION
implantation
occurs 7-9 days after fertilization
embryo
2-8 week development
fetus
9 week -> birth
chorioamnionitis
infection of both layers
membranes (2)
two fetal membranes that surround the developing embryo
- chorion (trophoblast)
- amnion (blastocyst)