Intro to Embryo 8-24 Flashcards Preview

Anatomy 6511 > Intro to Embryo 8-24 > Flashcards

Flashcards in Intro to Embryo 8-24 Deck (39)
1

Embryonic Period

Fertilization to 8 weeks - initial development of all major structures and establishment of all organ systems

2

Fetal Period

9th week (57 day) to 38th week - differentiation and growth of organs and tissues

3

Teratology

Study of abnormal development (generic/environmental causes)

4

LNMP

last normal menstrual period - 40 week pregnancy as opposed to 38 week pregnancy from fertilization to birth

5

Gametogenesis

Formation of PMGs, occurs at week 7

6

PMG

Primordial Germ cells - originate from endodermal cells of umbilical vesicle near origin of allantois as specific cells lining yolk sac. Migrate to gonads where they mature. Start as large cells recognizable 24 days after fertilization.

7

PMG

2N

8

Dorsal mesentary

Where germ cells migrate

9

Genital Ridge

Will form ovaries or testies

10

Indifferent Stage

Cannot differentiate between sexes

11

Oogenesis

Occurs in month 3 - at prophase I it halts. Only about 500 are ovulated. Oogonia to oocyte - 2 million oocytes.

12

Infundibulum

Like a funnel focused @ ovary.

13

Fimbriae

Little fingers over ovary from infundibulum. Smooth muscle then moves egg through ampula (fertilization likely occurs here).

14

Spermatogenesis

Spermatogonia to sperm

15

Maximum number of oocytes

Month 5 - 7 million oocytes

16

Month 9

All oocytes in meiosis I, birth, 600-800K oocytes

17

Menarche

First occurrence of menstruation, 400K oocytes

18

Oocyte wall

Immotile all are 23X, Corona radiata, Zona pellucida

19

Sperm

Motile, 23Y

20

2 hormones

FSH, LH (anterior pituitary) - prior to fertilization

21

FSH

follicular stimulating hormone. Tells 10-15 of the oocytes to start meiosis II and I.

22

LH

Leutinizing hormone - surge that causes oocyte to be spit out to be picked up by fimbriae

23

Zona RXN

causes only 1 sperm to be able to break into the nucleus

24

Monula

12-32 blastomeres. Important stage because of inner and outer cell mass.

25

Capacitation

Occurs after ejaculation 7hrs. Surface proteins remove acrosome, allows acrosome to interact with corona radiata and ZP.

26

Hyperactivation

Type of sperm motility, helps sperm penetrate ZP

27

Acrosome reaction

Allows sperm to break ZP.

28

Fertilization steps

Zona reaction, sperm and oocyte cell membranes break down and fuse. Oocyte completes meiosis and forms pronucleus. Haploid pronuclei fuse and form diploid zygote --- initiates cleavage. 1. Coronal cells 2. Acrosomal reaction 3. Fusion

29

Blastomeres

Early embryonic cells from zygote that start to form within 30 hours of fertilization. Zona pellucida confines cells.

30

Compaction

Begins at 8 cells

31

Ectopic Pregnancy

Implantation occurs in abnormal position - usually in uterine tubes.

32

Lithopedium

Embryo in abdomen, calcifies

33

Cervical implantation

Results in heavy bleeding.

34

Blastocyst

no more zona pellucida. Fluid enters blastocystic cavity and separates blastomeres. Trophoblast and Embryoblast

35

Trophoblast

Forms extra embryonic structures (placenta). Troph=nutrients.

36

Posterior Wall

Best place for implantation. Tropoblast cells attach to endometrium. Once this occurs, tropoblast differentiates into cytotrophoblast and syncytiotrophoblast (day 7).

37

Cytotrophoblast

Line blastocystic cavity

38

Syncytiotrophoblast

"Finger" type cells that extend and attach to endometrium.

39

Hypoblast

Small cuboidal cells that form from embryoblast. These will form the primary endoderm.