Notes + Study Questions of Development

Question 1

What are the 4 extraembryonic membranes?

Answer 1

1.) Amnion
2.) Yolk Sac
3.) Allantois
4.) Chorion

Question 2

What are the 3 period during development and what is the timeline for them?

Answer 2

1) Embryonic period: Fertilization - 8th week
2) Fetal period: 9th week - birth
3) Neonatal period: Birth - 28 days after birth

Question 3

What is capacitation?

Answer 3

process that helps sperm “get a burst of energy” to have their tails beat more vigorously

Question 4

The sperm must pass through which 2 structures around oocyte for fertilization?

Answer 4

corona radiata and zona pellucida

Question 5

What is the path of the sperm cell when penetrating secondary oocyte?

Answer 5

1) corona radiata
2) zona pellucida
3) plasma membrane
3) cytoplasm

Question 6

What triggers the acrosomal reaction?

Answer 6

glycoprotein in the zona pellucida

Question 7

What is the difference between fraternal and identical twins?

Answer 7

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.

Question 8

What is a morula, and how is it different from a zygote?

Answer 8

morula is a solid mass of cells that is produced after cleavage of a zygote

Question 9

The morula develops into a what?

Answer 9

blastocyst

Question 10

What are the differentiations of a blastocyst

Answer 10

1) trophoblast
2) embryoblast
3) internal fluid-filled cavity

Question 11

When does implantation occur?

Answer 11

7-8 days after fertilization

Question 12

What are the 3 primary germ layers and what do they develop to?

Answer 12

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

Question 13

What is the function of amniotic fluid?

Answer 13

protects developing fetus

Question 14

What is the site of early blood formation?

Answer 14

yolk sac

Question 15

What eventually forms into the umbilical cord?

Answer 15

allantois

Question 16

What becomes the principal embryonic part of placenta and secretes hCG?

Answer 16

chorion

Question 17

What makes up the placenta?

Answer 17

fetal portion: chorionic villi of chorion + maternal portion: decidua basalis of endometrium

Question 18

What organ or structure functions as protective barrier, stores nutrients, secretes hormones, maintains uterine environment and prepares mammary glands for breast feeding

Answer 18

placenta

Question 19

What are the 3 stages of labor

Answer 19

1) dilation
2) expulsion
3) placental stage

Question 20

What is the principal stimulus of lactation?

Answer 20

sucking action of infant

Question 21

What are the functions of a trophoblast?

Answer 21

secrete hCG

Question 22

What are the 4 hormones that affect lactation and what are their functions?

Answer 22

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