Exam 3: Basic Embryology

The epiblast gives rise to the three primary germ layers.

Approximately ________ percent of all children have some birth defect.

Figure 3.1 Use the diagram above to answer the following questions. -Which letter indicates the uterus?

The ectoderm develops into the epithelium of the skin, whereas this layer gives rise to the epithelial lining of the gut tube.

Which of the following adult structures derives from neural crest?

Briefly describe the formation of the nervous system.

Explain how conjoined twins may occur.

The solid mass of cells that results from cleavage of the zygote is the

Figure 3.1 Use the diagram above to answer the following questions. -Which letter indicates the oocyte?

By the end of week 3, the mesoderm has divided into the somites, intermediate mesoderm, and ________.

Briefly describe the two cellular layers that comprise the bilaminar embryonic disc and explain their importance in embryonic development.

Name three primary germ layers in the embryo.

The body's axis of development is determined by the

Mucus-producing glands of the respiratory tract arise from this layer.

Identical (monozygotic) twins are

The sex of the fetus can be determined externally by approximately month ________.

Quickening occurs (mother feels fetus moving).

In human embryos, the yolk sac is important because it

Limb buds emerge in the human embryo about

During the blastocyst stage, there are three cell layers evident.