chapter 24 Flashcards
gestation
38 week period of development (40 if counting from mother’s last menstrual period)
zygote
single cell resulting from union of mother/father cells
morula
cluster of identical cells from zygote
occurs in uterine tube generally
blastocyst
partially hollowed structure formed from morula before reaching uterus
group of cells within (inner cell mass) becomes embryo while the rest (trophoblasts) differentiate into tissue to support developing fetus
embryo vs fetus
embryo: growing offspring from conception to 3 months
fetus: growing offspring from 3 months to birth
decidua
maternal portion of the placenta
well-vascularized internal portion of endometrium
chorion
embryonic potion of placenta
forms chorionic villi
what are chorionic villi
projections that break down endometrial tissue creating venous sinuses with maternal blood
can be taken for genetic testing
how many arteries/veins are contained within the umbilical cord?
2 arteries and 1 vein
(arteries house LOW O2 blood and vein houses HIGH O2 blood)
ductus venosus
allows blood coming in from umbilical vein to bypass liver
foramen ovale
allows for high O2 blood to shunt from right atrium to left atrium (bypassing lungs)
ductus arteriosus
allows for high O2 blood to shunt from pulmonary artery to aorta (bypassing lungs)
what portions of the umbilical structures persist after birth?
proximal portions of umbilical arteries persist as arteries to urinary bladder
what is human chorionic gonadotropin?
hormone secreted by blastocyst after implantation
acts like LH stimulating growth and activity of corpus luteum (meaning high amounts of progesterone and estrogen for about 11-12 weeks)
when are miscarriages most likely?
when corpus luteum degenerates and it’s actions are taken over by the placenta
what does progesterone do during pregnancy?
- promotes endometrial secretions which nourishes embryo
- maintains endometrium
- decreases uterine muscle’s ability to contract
- prepares breasts for milk excretion
what does estrogen do during pregnancy?
promotes enlargement of uterus and breasts