Notes + Study Questions of Development Flashcards
What are the 4 extraembryonic membranes?
1.) Amnion
2.) Yolk Sac
3.) Allantois
4.) Chorion
What are the 3 period during development and what is the timeline for them?
1) Embryonic period: Fertilization - 8th week
2) Fetal period: 9th week - birth
3) Neonatal period: Birth - 28 days after birth
What is capacitation?
process that helps sperm “get a burst of energy” to have their tails beat more vigorously
The sperm must pass through which 2 structures around oocyte for fertilization?
corona radiata and zona pellucida
What is the path of the sperm cell when penetrating secondary oocyte?
1) corona radiata
2) zona pellucida
3) plasma membrane
3) cytoplasm
What triggers the acrosomal reaction?
glycoprotein in the zona pellucida
What is the difference between fraternal and identical twins?
Identical twins stem from only one ovum that splits and are always the same sex while fraternal twins stem from 2 different ovum that were fertilized by different sperm cells.
What is a morula, and how is it different from a zygote?
morula is a solid mass of cells that is produced after cleavage of a zygote
The morula develops into a what?
blastocyst
What are the differentiations of a blastocyst
1) trophoblast
2) embryoblast
3) internal fluid-filled cavity
When does implantation occur?
7-8 days after fertilization
What are the 3 primary germ layers and what do they develop to?
1) ectoderm
- brain + nerves, epidermis
2) mesoderm
- mesenchyme > blood, muscles, bones + other connective tissue derivatives
3) endoderm
- epithelial lining of digestive tract, respiratory tract, smooth endothelial lining of blood vessels
What is the function of amniotic fluid?
protects developing fetus
What is the site of early blood formation?
yolk sac
What eventually forms into the umbilical cord?
allantois
What becomes the principal embryonic part of placenta and secretes hCG?
chorion
What makes up the placenta?
fetal portion: chorionic villi of chorion + maternal portion: decidua basalis of endometrium
What organ or structure functions as protective barrier, stores nutrients, secretes hormones, maintains uterine environment and prepares mammary glands for breast feeding
placenta
What are the 3 stages of labor
1) dilation
2) expulsion
3) placental stage
What is the principal stimulus of lactation?
sucking action of infant
What are the functions of a trophoblast?
secrete hCG
What are the 4 hormones that affect lactation and what are their functions?
1) human placental lactogen (hPL): lactation
2) prolactin: milk production
3) oxytocin: contraction of cells + ducts in breast (let-down reflex)
4) estrogen+progesterone: development of breasts to prepare for lactation
