Exam 20: Development

For fertilization to occur,many sperm are needed to

The extraembryonic membrane that surrounds the embryo and secretes a fluid that cushions it is the

Fertilization usually takes place in the

Milk is not produced unless prolactin is stimulated by a baby's suckling.

What is the term for the postnatal period that begins at birth and lasts about 4 weeks?

The expulsion stage of labor generally lasts for 3-4 hours.

The longest period in prenatal development is the _____ period.

The extraembryonic membrane that contributes to the formation of umbilical blood vessels is the

Near the end of gestation,the inhibition of uterine muscle contractions is removed by _____ levels of _____.

The ectoderm,mesoderm,and endoderm develop during the first two weeks after fertilization.

Near the end of gestation,uterine muscles become sensitized for contractions by _____ levels of _____.

The cells around the periphery of a blastocyst form the

What is the term for the extraembryonic membrane that contributes to the formation of the placenta?

What is the term for the region where fertilization generally occurs?

The relationship of the hypothalamus,oxytocin,and uterine contractions is an example of a _____ feedback mechanism.

The embryonic period lasts for about six months.

The vessel that carries oxygenated blood from the placenta to the fetus is the

Labor is the

With prostaglandins,what is the hormone that stimulates uterine contractions?

The term gestation refers to the