Embryology and Development

Embryology

the study of development following fertilization.

Fertilization

the union of gametes, sperm and egg.

Zygote

fertilized egg.

Morula

the solid mass of cells

Radial Symmetry

sliced like a pizza, would be nearly identical.

Bilateral Symmetry

sliced in half would be a mirror image of the other.

Gastrula Stage

embryo transforms from a 1 dimensional blastula into a multi-dimensional structure the gastrula.

Ectoderm

outside layer.

Mesoderm

middle layer.

Endoderm

Inside layer.

Ectoderm (outside layer)

skin cells, nervous system, pigment cells.

Mesoderm (middle layer)

cardiac cells, skeletal cells, smooth tissue.

Endoderm (inside layer)

digestive cells, lung cells.

Neurulation

the nervous system begins to develop.

Neural Plate

surface of the embryo

The Neural Groove

central nervous system

The Neural Tube

Spinal Cord.