Chapter 3 - Prenatal Development

Conception to Implantation in uterine wall

What time period is the “Germinal Period” / The Period of the zygote

Week 3 to Week 8

What time period is the Period of the embryo

Week 9 to Birth

What time period is the Period of the fetus

14 days

How long is the period between Conception and Implantation for a cell.

Trophoblast cells

What stage/type of cell implants itself into the uterine wall to begin the Embryotic Period?

Amnion

The innermost membrane that encloses the embryo, acting as a supporting structure for an embryo

Chorion

The outermost membrane that encloses the embryo, acting as a supporting structure for an embryo

Yolk Sack

membranous sack attached to embryo to provide nutrition and aiding blood cell production, acts as a supporting structure for an embryo

Placenta

Semi permeable membrane that connects embryo to mother. Allows the secretion of certain vital substances from mother to baby (proteins, water, gases)

Umbilical Cord

Formed from the Chorion, linkage between fetus and placenta to carry the nutrients from mother to fetus.

Ectoderm

Cell layer in the Period of the embryo that forms into the nervous system, skin, and hair

Mesoderm

Cell layer in the Period of the embryo that forms into muscles, bones, and the circulatory system

Endoderm

Cell layer in the Period of the embryo that forms into the digestive system, lungs, urinary tract, and other vital organs

Neural tube

Structure from which the brain and spinal cord form, formed by a portion of the Ectoderm

Indifferent gonad

Term for the beginning of the formation of sex organs in the second month of prenatal development. Further development is based on the presence of a Y chromosome

2.5 cm long, 7 g

What is the average size and weight of an embryo in the second month