PRE-EMBRYONIC PERIOD: WEEK I

In the following note, the first week of embryonic development will be described. The following key words / terminology will be defined or described.

Fertilization

Capacitation

Acrosome Reaction

Zygote

Cleavage

Morula

Inner cell mass or embryoblast

Outer cell mass or Trophoblast

PRINCIPLES OF TERATOLOGY AND CRITICAL STAGES OF DEVELOPMENT

This note defines a teratogen and explains the principles governing the capacity of a teratogen to produce teratogenic effect with emphasis on the effect of a teratogen on different developmental stages.