Slides: Implantation and

Embryonic & Fetal Development

1

pronuclei

Zona

2

Zona

Polar Body

Blastomere

3

Zona

Blastomeres

4

Zona

Blastomeresearly blastocyst

‘hatching’ from zona

Zona degrading

5

Inner Cell Mass

Trophoblast

Blastocyst

6

uterine gland endometrium

implanting conceptus

7

syncytio-trophoblast

lacunae

embryonic disc

8lacunar network amnion embryonic disc

yolk sac

cytotrophoblast

9lacunar network amnionembryonic disc

yolk sac

chorion

10intervillous space = lacunar network

connecting stalkembryonic disc

yolk sac

chorionchorionic villi

11

epiblast

mesoderm

endoderm

The Embryonic Disc

12

primitive streak

connecting stalk

embryonic disc

yolk sac

chorion

13

amnion

ectoderm

endoderm notochord

mesoderm

14

brain

connecting stalk

umbilical cord

somites

yolk sac chorion

heartpharynx

15

umbilical cord

amnion

forebrain

yolk sac

heart

pharyngeal arches

somites

16

apical ectodermal ridge (AER)

Limb bud

limb mesoderm

17

umbilical cord

amnion

yolk sac chorionic villi

18

amnion

umbilical cord

umbilical hernia: intestines

Crown-Rump length

30 mm = 1.25 inch

19Placenta = villous chorion amnionsmooth chorion

Crown-Rump length: 93 mm = 3.5 inches