Embryonic Development-Gastrulation Flashcards

The blastula stage signals the end of the period in embryogenesis known as cleavage.

The blastula can be defined in anatomical terms as a hollow stage in the embryo’s development, with a cavity (the blastocoele), surrounded by an epithelial cellular layer called the blastoderm.

***The teleosts (bony Fishes) have a blastoderm that does not surround the “Blastocoele”

1. Rearrangement of cells of the embryo via morphogenetic movements
2. Slower mitotic rate
3. No significant growth
4. metabolic change (increased oxidation)
5. Embryonic nuclei become active
6. Qualitative change in protein population

1. Rearrangement of cells of the embryo via morphogenetic movements
2. Slower mitotic rate
3. No significant growth
4. metabolic change (increased oxidation)
5. Embryonic nuclei become active
6. Qualitative change in protein population

Real

New

Mice

Eat

Qualil

1. Micromeres- sea urchin
2. Gray crescent- frog
3. Dorsal Lip of Blastopore- Amphibian, Frog*
4. Primitive Streak- chick, human

Primary Organizers

Note: clevage is equal at 2 cell stage

16 cell stage early clevage not complete

no green no orange but later these sections will become

Primary Organizers

Primary Organizers

Primary Organizers

Blastoderm does not surround the blastocoel, instead has cell death tube . Removed during excavation.

Ectoderm Blue/Green

Endoderm Yellow

Mesoderm Red/Orange

Prospective Fate of a cell or group of cells due to their anatomical position in the embryo

Developmental Potential of a cell or group of cells under varying conditions, wherein new influences (inductive influences) are encountered.

When one cell or group of cells influences the fate of another cell or group of cells without necessarily affecting itself

The cell or group of cells responsible for the influence mentioned above.

The ability of cells to respond to the influence of an inductor

Period of competency is a fixed period of time.

Fixing the fate of cells during development(narrowing of the prospective potency so that it more closely equals the prospecting significance) when the prospective potency and prospective significance are the same we say that cells are fully determined (happens during the s-period of the cell cycle)

Physical (Anatomical) and Genetic/Biochemical (Physiological) expression of the fixed fate of cells.

Spatially different parts of the embryo take on different anatomical structure. Morphogenesis/ Organogenesis

Over a period of time different cells in an organ differentiates into different, specific cell types. Cytodifferentiation Histogenesis

Spacial Differentiation

Temporal Differentiation

Invagination- pushing in of an epithelium

Epiboly- Spreading of an epithelial layer so that it covers over epithelia

Ingression (immigration)- breaking-up of an epithelium followed by inward migration of individual cells

Involution- inward migration of an epithelium

Separation of epithelial layers

Local thickening followed by evacation

• Separation of epithelial layers
• Local thickening followed by evacation

TOP

Red- Non-notochordal mesoderm

Orange- Chrdomesoderm

Yellow- Endoderm

Green- Neural Ectoderm

Blue- Epidermal Ectoderm

BOTTOM

Red- Non-notochordal mesoderm

Orange- Chrdomesoderm

Yellow- Endoderm

Green- Neural Ectoderm

Blue- Epidermal Ectoderm

Diffuse

Cotyledons

Zonary

Discoidal

Bidiscoidal

Bidiscodial-same as discoidal but with 2 disks

NO

SUCH

STUPID

LUCK

I

BROUGHT

APPLES

ANYWAY

1. Neural tube formation with epilepsy
2. Separation of the chordomersoderm from segimental mesoderm
3. Somites forom from dorsal portion of segmental mesoderm
4. Lateral plate mesoderm splits to form splanchnic mesoderm, somatic mesoderm, coelom
5. Intermediate mesoderm forms nephrostone
6. Body folds close forming gut
7. Exocoele forms amniotic folds
8. Amniotic folds form amnion and chorion (serosa)
9. Amniotic folds form yolk sacs

Primary Organ Rudiment Formation in the Chick

1. Neural tube formation with epilepsy
2. Separation of the chordomersoderm from segimental mesoderm
3. Somites forom from dorsal portion of segmental mesoderm
4. Lateral plate mesoderm splits to form splanchnic mesoderm, somatic mesoderm, coelom
5. Intermediate mesoderm forms nephrostone
6. Body folds close forming gut
7. Exocoele forms amniotic folds
8. Amniotic folds form amnion and chorion (serosa)
9. Amniotic folds form yolk sacs

• Primary Organ Rudiment Formation in the Frog
• Discovery of Primary Embryonic Organizer by Hilde mangold
• demonstrated this effect with the frog’s dorsal lip (chordomesoderm)

Mangold ROL rude old lip

demonstrated this effect with the frog’s gray crescent (presumptive chordomesoderm)

?what a cell becomes vs its ability to become something ?

Always

Hang

Heavy

Xrays

1. Autoplastic Transplant (autograft)- donor and host same individual
2. Homolpastic transplant (homograft)- donor and host are different individuals of the same genus and species
3. Heteroplastic transplant (hetrograft)- donor and host of same genus but different species
4. Xenoplastic transplant (xenograft) donor and host more distant than genus

donor and host same individual

donor and host are different individuals of the same genus and species

donor and host of same genus but different species

donor and host more distant than genus