Three Stages of Prenatal Development
Intro Images:Photo Credit:
See and feel scaled models of three stages of prenatal development described below.
This lentil-sized embryo has an amazing amount of detail at the microscopic level. The heart begins beating in a regular rhythm in about 6-10 days. The pharyngeal arches form the head and neck. The arms and legs are simple buds and the eyes and nose are discs of cells that will continue to develop into recognizable organs in the next 5 weeks
An amazing amount of growth has taken place in only 3 months. The head is much more developed compared to the rest of the body.
This fetus is still less than half way to term. Most of the major organs are developed enough to begin working. A fetus delivered at this time cannot survive due to lack of developed aveoli in the lungs.