Chapter 5

Question 0

ovulation

Answer 0

the release of a mature egg form an ovary

Question 1

Ovum

Answer 1

an unfertilized egg

Question 2

gestational age

Answer 2

the length of time since the conception of a developing organism

Question 3

germinal stage

Answer 3

the prenatal stage that lasts from conception to 2 weeks postconception

Question 4

blastocyst

Answer 4

a hollow ball of cells that consists of the inner cell mass ( which becomes the embryo) and an outer ring of cells (which becomes the placenta and chorion)

Question 5

inner cell mass

Answer 5

a solid clump of cells in the blastocyst, which later develops into the embryo

Question 6

trophoblast

Answer 6

the outer ring of cells in the blastocyst that later develops into the support system for the pregnancy

Question 7

embryonic stage

Answer 7

the prenatal stage that lasts from 2 weeks to 2 monthss postconception

Question 8

embryo

Answer 8

the developing organism from conception to the en of the second month of pregnancy

Question 9

chorion

Answer 9

the outer fetal membrane that surrounds the fetus and gives rise to the placenta

Question 10

amnion

Answer 10

the inner fetal membrane that surrounds the etus and is filled with amniotic fluid

Question 11

placenta

Answer 11

the organ that supports a pregnancy by bringing oxygen and nutrients to the embryo from the mother through the umbilical cord and carrying away fetal waste products

Question 12

fetus

Answer 12

the developing organism from the end of the eighth week postconception until birth

Question 13

ectoderm

Answer 13

the outermost layer of the inner cell mass that later becomes the skin, sense organs, brain, and spinal cord

Question 14

endoderm

Answer 14

the innermost layer of the inner cell mass that later becomes the respiratory system, digestive system, liver and pancreas

Question 15

mesoderm

Answer 15

the middle layer of the inner cell mass that later becomes the muscles, bones, blood, heart, kidney, and gonads

Question 16

organogenesis

Answer 16

the process in prenatal development by which all of the major organ systems of the body are laid down

Question 17

cephalocaudal development

Answer 17

A principle whereby development proceeds from the head region down through the body

Question 18

critical period

Answer 18

a period of time during which development is occurring rapidly and the organism is especially sensitive to damage, which often is severe and irreversible

Question 19

fetal stage

Answer 19

the prenatal stage that lasts from 2 months postconception until birth