Ch. 28 - Pregnancy & Human Development Flashcards
When can a sperm fertilize the egg?
Sperm has to be capacitated
What hormones are produced by the placenta?
Human chorionic gonadotropin (hCG), human placental lactogen (hPL), human chorionic thyrotropin (hCT), relaxin
Put in order - blastocyst, morula, zygote.
Zygote, morula, blastocyst
What is the function of relaxin?
Causes pelvic ligaments and pubic symphysis to relax, widen, and become more flexible.
What process produces the 3 germ layers?
Gastrulation
What are the 3 germ layers?
Ectoderm (outer skin), mesoderm (middle skin), endoderm (inner skin)
What occurs during cleavage?
Period of rapid mitotic division, provides building blocks for constructing the embryo
During what stage of labor is the fetus delivered?
Expulsion stage
What stage of labor is for afterbirth?
Placental stage
What two hormones are needed to allow milk ejection?
Oxytocin & prolactin
Neural tissue is formed by what germ layer?
Ectoderm
Muscle tissue is formed by what germ layer?
Mesoderm
What does the trophoblast form?
Placenta
What happens if polyspermy occurs?
Too much DNA and are nonviable (die)
What happens if the foramen ovale fails to close at birth?
Deoxygenated blood will flow into left atrium and go to rest of body. Blood won’t have enough oxygen. Baby will turn blue
Define Braxton-hicks contractions.
False labor. Myometrium becomes increasingly irritable and weak, irregular uterine contractions begin. Prepares for labor.
What is the first “milk” produced by the mother called?
Colostrum
What is a fertilized egg called?
Zygote
When do you officially call the developing individual a fetus rather than an embryo?
At 9 weeks
What hormone does the mother’s pituitary continue to produce milk?
Oxytocin
What starts labor?
Estrogen levels rise, increase oxytocin receptors on uterus myometrial cells, Braxton hicks contractions begin to prepare
What does implantation signal (the division of what)?
Rapid mitotic division of zygote
What happens to sperm once it enters the female?
Becomes capacitated
What occurs at the implantation stage?
Endometrium thickens, diffusion of blood, placenta makes hCG
What do the umbilical arteries carry?
Nutrients
At what stage is the placenta fully prepared to fulfill the needs of the fetus?
End of the third month of pregnancy (end of first trimester)
What is an ectopic pregnancy, and why is it problematic?
Embryo implants in any site other than the uterus. Can’t establish placenta or accommodate growth, can rupture unless spotted or abort itself
What allows implantation of the blastocyst?
Prepared endometrium
The placenta is made up of a contribution from mother and fetus. What portion is from the fetus?
Villous chorion
What happens to the heart once the infant takes it’s first breath?
Shunts close, functions normally
What is placenta previa? What often occurs with this condition? How is it treated?
Placental formation adjacent to or across the internal os of the uterus. Could tear the placenta.
