CHAPTER 3 PRENATAL DEVELOPMENT

Question 1

germinal period

Answer 1

The period of prenatal development that takes place in the first two weeks after conception. It includes the creation of the zygote, continued cell division, and the attachment of the zygote to the uterine wall.

Question 2

blastocyst

Answer 2

The inner layer of cells that develops during the germinal period. These cells later develop into the embryo.

Question 3

trophoblast

Answer 3

The outer layer of cells that develops in the germinal period. These cells provide nutrition and support for the embryo.

Question 4

embryonic period

Answer 4

The period of prenatal development that occurs two to eight weeks after conception. During the embryonic period, the rate of cell diff erentiation intensifies, support systems for the cells form, and organs appear

Question 5

amnion

Answer 5

Prenatal life-support system that is a bag or envelope containing a clear fluid in which the developing embryo floats.

Question 6

placenta

Answer 6

A life-support system that consists of a disk-shaped group of tissues in which small blood vessels from the mother and off spring intertwine.

Question 7

organogenesis

Answer 7

Organ formation that takes place during the first two months of prenatal development.

Question 8

fetal period

Answer 8

The period from two months after conception until birth, lasting about seven months in typical pregnancies

Question 9

teratogen

Answer 9

From the Greek word tera, meaning “monster,” this term refers to any agent that causes a
birth defect. Teratology is the field of study that investigates the causes of birth defects. Only about half of all potential effects appear at birth.

Question 10

3 factors that influence the severity of the damage to an embryo or fetus and the type of defect

Answer 10

-Dose.
• Genetic susceptibility . The type or severity of abnormalities caused by a teratogen is linked to the genotype of the pregnant woman and the genotype of the embryo or fetus
• Time of exposure . Damage during the germinal period may even prevent implantation. In general, the embryonic period is more vulnerable than the fetal period

Question 11

Teratogens (list ‘em)

Answer 11

Alcohol, prescription drugs, nicotine, caffeine, cocaine. meth, heroine, incompatible blood types, environmental factors, maternal disease, maternal diet and nutrition, maternal age, emotional states and stress