Gastrulation Flashcards Preview

CELL1001 > Gastrulation > Flashcards

Flashcards in Gastrulation Deck (44)
Loading flashcards...
1

Invagination

Folding of the surface epithelium of the blastula usually at the vegetal pole to form a central tube, archenteron

2

Blastopore

Point of invagination

3

Involution

Similar to invagination and also forms an archenteron that extends towards the animal pole from a blastopore

4

Ingression

Migration of individual cells from surface epithelium into the interior of the embryo

5

Primary mesenchyme cells

Apical surface of vegetal plate form bottle cells which ingress into blastocoel, remaining clustered at vegetal plate to form precursors of the mesoderm

6

Cadherins

Ca2+ dependent adhesion molecules

7

Convergent-extension

Cells become elongated perpendicular to axis of elongation and form actin and myosin rich lamellipodia at opposite poles. Lamellipodia used to exert traction on each other and drive cell intercalation narrowing invaginating tube and elongating towards animal pole

8

Secondary mesenchyme cells

Complete elongation of archenteron. Form at invaginating tip of archenteron and produce filopodia

9

Filopodia

Long cytoplasmic extensions that search for basal surface of animal pole§

10

Trophoblast

Outer epithelium at 16-32 cell stage of holoblastic cleavage, forms chronic layers of placenta

11

Inner cell mass

Small population of internal mesenchyme- like cells at 16 to 32 cell stage

12

First step in development of mammalian ICM

Formation of hypoblast and epiblast

13

Hybolast layer is adjacent to

Blastocoel

14

Heuser's membrane

Layer of exraembryonic endoderm deriving from hypoblast spreading around trophoblast lining the blastocoel

15

Yolk sac

Enclosed cavity by Heuser's membrane

16

Meckel's diverticulum

Small bulge in the small intenstine and is most frequent congenital malformation of digestive tract

17

Amniotic membrane

Layer of flattened epithelial, extraembroynic ectoderm,cells lining amnion formed by epiblast

18

Synctiotrophoblast

Tissue formed when trophobolast is in contact with endometrium. Highly invasive and penetrates uterine walls, secreting enzymes that digest the extracellular matrix which normally surrounds and connects cells.

19

Cytotrophoblast

Trophoblast cells lining blastocoel in contact with ICM remaining a single layered cellular epithelium

20

Lacunae

Cavities in the synctiotrophoblast filled with maternal blood from uterine capillaries

21

HCG

Required to maintain progesterone production by the corpus luteum

22

Buccopharyngeal membrane

Formed by epiblast layer at future rostral pole

23

Cloacal membrane

Formed by hypoblast layer at future caudal pole

24

Primitive streak

Ridge of cells at midlien of caudal half of epiblast layer on 14th day

25

Node

Mould of cells at rostral end of primitive streak

26

Somites

Paired blocks formed progressively along rostral-caudal axis by paraxial mesoderm.

27

Anecephaly

Failure to close anterior neural tube causes brain degeneration and failure to form cranium

28

Spina bifida

Failure to close posterior end leads to severe paralysis

29

Pharyngeal arches

Cranial neural crest cells which differentiate as cartilage and bone migrate into ventral region of head

30

Phylotypic stage

Where vertebrate embryos are most similar