Pregnancy Flashcards
What is fertilization
The union of a haploid sperm and egg
Where does fertilization occur
The fallopian tubes
What is cleavage
Early cell division in Fallopian tube
What does the inner cell mass do
Gives rise to the embryo
What does the trophoblast layer do
Gives rise to extra-embryonic structures
When does implantaion occur
8-10 days after fertilization
What is the structure which implants the endometrium
The blastocyst
What is the blastula stage
when the tropoblast cells secrete hCG which prevents menstruation by acting on the corpus luteum (maintains it)
What will the uterus keep producing during the blastula stage
progestrone to prevent uterine contractions
What is the Gastrula stage
Beginning of morphogenesis due to differentiation
What is the embryonic disk
The inner cell mass that flattens during the Gastrula stage
What are the three germ layers of the gastrula
Ectoderm
Mesoderm
Endoderm
Ectoderm
Nervous system, skin
Mesoderm
Skeleton, muscles, reproductive structures
Endoderm
Lining of the digestive and respiratory systems, endocrine glands
Chorion
Outermost membrane, chrionic villi becomes the fetal portion of the placenta
Amnion
Grows to enclose the embryo, fills with amniotic fluid
Yolk Sac
Suspended from embryo; forms digestive tract and produces first red blood cells
Allantosis
Foundation of umbilical cord; degeneratees in second month
Amniotic Cavity
The space between the inner cell mass and trophoblast
Amniotic Sac
Holds the fetus and the amnion
Placenta
Organ made from cells from the fetus and mother
What does the placenta produce and why
progesterone to inhibit uterine contractions
Umbilical Cord
The veins and arteries of the placenta that attach to the blood vessels of the fetus
