Packet 28

Question 1

From fertilization to birth

Answer 1

fertilization
implantation
placental development
fetal development
gestation
labor
parturition (birth)

Question 2

Haploid sperm nucleus & haploid secondary oocyte nucleus merge to form

Answer 2

single diploid nucleus

Question 3

Occurs in uterine tube within 24 hours after ovulation (oocyte dies in 24 hours)

Answer 3

fertilization

Question 4

events occurring before fertilization

Answer 4

1. peristalsis of uterine tube and cilia transport oocyte to uterus
2. sperm swims to oocyte by flagella
3. capacitation (final maturation) of sperm occurs within female

Question 5

sperm swim towards oocyte by means of flagella

—–stimulate uterine contractions that help move sperm towards the oocyte

Answer 5

prostaglandins

Question 6

sperm penetrates the ___ cells around the oocyte

Answer 6

granulosa

Question 7

Sperm digests its way throughthe

Answer 7

zona pellucida

Question 8

First sperm to fuse with oocyte membrane triggers the slow & the fast block to

Answer 8

polyspermy

Question 9

1-3 seconds after contact, oocyte membrane depolarizes & other cells can not fuse with it =

Answer 9

fast block to polyspermy

Question 10

depolarization triggers the intracellular release of Ca+2 causing the exocytosis of molecules hardening the entire zona pellucida

Answer 10

slow block to polyspermy

Question 11

Events within the egg

–sperm entry triggers___

Answer 11

oocyte to complete meiosis II and dump second polar body

Question 12

Events within the egg

—Once inside the oocyte

Answer 12

the sperm loses its tail & becomes a male pronucleus

Question 13

Events within the egg

—the true moment of fertilization is when

Answer 13

Fusion of male & female haploid pronuclei

Question 14

fertilized ovum (2n) is called

Answer 14

zygote

Question 15

Rapid mitotic cell division of embryo is called

Answer 15

cleavage

Question 16

Formation of the morula

Day 1-4

Answer 16

Day 1. 1st cleavage in 30 hours produces 2 blastomeres

Day 2. 2nd cleavage on 2nd day

Day 3. By 3rd day has 16 cells

Day 4. By day 4 has formed a solidball of cells

Question 17

By day 4 has formed a solidball of cells called

Answer 17

morula

Question 18

is a hollow ball of cells that enters the uterine cavity by day 5

Answer 18

blastocyst

Question 19

outer covering of cellscalled

Answer 19

trophoblast

Question 20

fluid-filled cavity called

Answer 20

blastocele

Question 21

Trophoblast & part of innercell mass will develop into

Answer 21

fetal portion of placenta

Question 22

most of the inner cell mass will become

Answer 22

the embryo

Question 23

Implantation consists of

Answer 23

1. Attachment of blastocyst to endometrium
2. Trophoblast develops 2 distinct layers
3. Trophoblast secretes human chorionic gonadotropin

Question 24

occurs 6 days after fertilization

implants with inner cell mass in contact with the endometrium

Answer 24

attachment of blastocyst to endometrium

Question 25

Trophoblast develops 2 distinct layers

Answer 25

1. syncytiotrophoblast | 2. cytotrophoblast

Question 26

secretes enzymes that digest the endometrial cells

Answer 26

syncytiotrophoblast

Question 27

distinct layer of cells that defines the original shape of the embryo

Answer 27

cytotrophoblast

Question 28

secretes human chorionic gonadotropin (hCG) that helps the corpus luteum maintain the uterine lining

Answer 28

Trophoblast

Question 29

Development of an embryo outside the uterus Most often in uterine tube --common causes are blockages of uterine tube such as tumors or scars from pelvic inflammatory disease --symptoms are missed menstrual cycles, bleeding & acute pain

Answer 29

ectopic pregnancy

Question 30

ectopic pregnancy are twice as common in smokers because

Answer 30

nicotine paralyzes the cilia

Question 31

Day 8 - cytotrophoblast forms - ectoderm & endoderm together form

Answer 31

amnion and amnionic cavity embryonic disk

Question 32

cells of inner cell mass on amnionic cavity form

Answer 32

ectoderm

Question 33

cells bordering on blastocele form

Answer 33

endoderm

Question 34

endodermal cells divide to form a hollow sphere (yolk sac) cytotrophoblast cells divide to fill the spaces surrounding the yolk sac with extraembryonic mesoderm

Answer 34

Day 12

Question 35

Day 14 | cells of embryonic disc produce 3 distinct layers

Answer 35

endoderm mesoderm ectoderm

Question 36

forms epithelial lining of GI & respiratory

Answer 36

endoderm

Question 37

forms muscle, bone & other connective tissues

Answer 37

mesoderm

Question 38

develops into epidermis of skin & nervous system

Answer 38

ectoderm

Question 39

Formation of Embryonic Membranes

Answer 39

Yolk sac amnion chorion allantois

Question 40

site of early blood formation gives rise to gonadal stem cells (spermatogonia & oogonia)

Answer 40

Yolk sac

Question 41

surrounds embryo with fluid: shock absorber, regulates body temperature & prevents adhesions fluid is filtrate of mother’s blood + fetal urine examine a sample of it for embryonic cells (amniocentesis)

Answer 41

Amnion

Question 42

becomes the embryonic contribution to the placenta derived from trophoblast & mesoderm lining it gives rise to human chorionic gonadotropin (hCG)

Answer 42

Chorion

Question 43

outpocketing off yolk sac that becomes umbilical cord

Answer 43

allantois

Question 44

all of endometrium lost as placenta | --equals all of the endometrium, except stratum basalis

Answer 44

Decidua

Question 45

portion of endometrium deep to chorion

Answer 45

Decidua basalis

Question 46

part of endometrial wall that covers implanted embryo

Answer 46

Decidua capsularis-

Question 47

part ofendometrial wall not modifiedby embryo until embryo bumps into it as it enlarges

Answer 47

Decidua parietalis-

Question 48

Decidua capsularis fuses with

Answer 48

decidua parietalis

Question 49

forms during 3rd month | chorion of embryo & stratum functionalis layer of uterus

Answer 49

Placenta

Question 50

``` extend into maternal blood filled intervillous spaces --- maternal & fetal blood vessels do not join & blood does not mix --diffusion of O2, nutrients, wastes --stores nutrients & produces hormones --barrier to microorganisms, except some viruses -----AIDS, measles, chickenpox, poliomyelitis, encephalitis --not a barrier to drugs such as alcohol ```

Answer 50

Chorionic villi

Question 51

contents of umbilical cord

Answer 51

1. 2 arteries that carry blood to the placenta 2. 1 umbilical vein that carries oxygenated blood to the fetus 3. primitive connective tissue

Question 52

Stub drops off in 2 weeks leaving a scar called

Answer 52

umbilicus