Developmental Biology (Bio 445)

Lecture Guide

(pages 72-82 Moore)

 

NOTE: We will also cover some material in Wolpert, Chap 8 (up to Neurulation).  We may not get into this at all until Wednesday.  But please preview that chapter also.

 

3-4 weeks of Development.

 

….finishing off the notochord….

 

The floor of the notochordal process AND the underlying endoderm degenerate leaving the flattened, grooved ____________________

 

The floor of the notochordal process AND the underlying endoderm degenerate leaving the flattened, grooved ____________________.

 

Notochordal cell proliferation causes an _________________ of the notochordal plate and the formation of the rod-shaped ___________.

 

 

Neurulation

 

Neurulation is the formation of the ___________________.

 

The processes involved in neurulation are completed at the end of week 4.

 

During neurulation, the embryo may be referred to as ____________.

 

 

The notochord induces the overlying ectoderm to thicken and form the neural plate.

 

The ectoderm of the neural plate gives rise to the (______________) CNS.

 

Location:

     cranial to the _____________________

     dorsal to the ______________________

 

The neural plate extends as far as the _________________membrane.

 

 

 

Invagination of the neural plate forms the ________________ bounded on either side by the _____________________

 

The cranial _____________ become prominent and are the first indications of ____________________________.

 

By the end of the 3rd week, the neural folds have moved together and fused into the ___________________.

 

 

 

 

 

 

 

 

 

Neural Crest Cell Formation

 

As the neural tube closes, ______________ along the “crest” of the neural folds, lose their ____________ to the surrounding epithelial cells.

 

These ________________ migrate to first form a flattened layer between the ____________ and the overlying ectoderm called, collectively, the “_______________”.

 

These cells continue to migrate _______________ into right and left masses on either side of the _______________ where they will eventually form __________________.

 

neural crest cells give rise to:

         

                   __________________________________________

                   __________________________________________

                   __________________________________________

                   __________________________________________

                  

Somite Formation

 

On each side of the notochord/neural tube, the mesoderm _________________________into a column of tissue called the _____________________________.

 

Adjacent to the paraxial mesoderm is the _______________________

 

Finally, the most lateral aspect of the mesoderm thins and is called the _________________________

 

 

 

 

Near the end of the 3rd week, the paraxial mesoderm becomes paired, cubed bodies of mesoderm called the _______________________

 

They develop __________________ and give rise to:

          Most of the ___________________________ (and musculature)

 

 

 

Intraembryonic coelom

 

The beginnings of the embryonic body cavity are first seen as isolated _______________ in the ___________________________.

 

These spaces soon coalesce to form the single horseshoe-shaped cavity, the ____________________________.

 

the ___________________ divides the lateral mesoderm into 2 layers:

 

_______________ (parietal) – continuous with mesoderm covering the amnion

 

________________(visceral) – continuous with mesoderm covering the yolk sac

 

additional terminology:

the somatic mesoderm + ectoderm = _______________________

the splanchnic mesoderm + endoderm = _____________________

 

Chorionic Villi Development

 

____________________are projections of ________________ cells into the syncytiotrophoblast.