Exam 4: Development

The umbilical cord contains three blood vessels: two umbilical arteries and one umbilical vein.

The embryonic disc appears first as a bilayered structure of ectoderm and endoderm next to the amniotic cavity.

The name for a fertilized ovum that contains one nucleus is a _____.

Cleavage

The morula enters the uterine cavity on day 4 or 5.

Discuss the formation of both dizygotic (fraternal) and monozygotic (identical) twins.

Dizygotic (fraternal) twins result from

Differentiation of the tissue of the embryo into the three primary germ layers begins _____ (before or after) implantation.

All major body systems have begun to develop by the end of _____.

Place the following events in the correct order and briefly define each: embryonic development, implantation, fetal period, fertilization, labor, cleavage, placental development.

The space indicated by the letter B is called the _____.

On the diagram, 1 is pointing to

The region indicated by the letter E is the _____.

Which of the following structures actually implants into the endometrium of the uterus?

The letter D is pointing to the layer in which the _____ implants.

Bone formation begins during the _____ month of embryonic development.

The placenta has two distinct parts: the fetal portion formed by the _____ and the maternal portion formed by the _____.

The _____ forms all skeletal and cardiac muscle tissue and most smooth muscle tissue.

Which of the following is the most important event during the third week of development?

Place the following in the correct order: 1) aided by enzymes on their surface, sperm penetrate the cells of the corona radiata 2) acrosomal reactions are triggered when sperm bind to receptors in the zona pellucida 3) syngamy occurs when a sperm cell binds to receptors on the oocyte's plasma membrane 4) acrosomal enzymes from many sperm digest through the zona pellucida 5) zygote is formed