Chapter 4&5: Prenatal Development

Question 1

prenatal development

Answer 1

development that occurs between the moment of conception and the beginning of the birth process.

Question 2

period of the zygote (germinal period)

Answer 2

first phase of prenatal development, lasting from conception until the developing organism becomes firmly attached to the wall of the uterus.

Question 3

period of the embryo

Answer 3

second phase of prenatal development, lasting from the third through the eighth prenatal week, during which the major organs and anatomical structures take shape.

Question 4

period of the fetus

Answer 4

third phase of prenatal development, lasting from the ninth prenatal week until birth; during this period, all major organ systems begin to func- tion and the fetus grows rapidly.

Question 5

embryo

Answer 5

name given to the prenatal organism from the third through the eighth week after conception.

Question 6

implantation

Answer 6

the burrowing of the blastocyst into the lining of the uterus.

Question 7

amnion

Answer 7

a watertight membrane that sur- rounds the developing embryo, serving to regulate its temperature and to cushion it against injuries.

Question 8

chorion

Answer 8

a membrane that, as above, becomes attached to the uterine tissues to gather nourishment for the embryo.

Question 9

placenta

Answer 9

an organ, formed from the lining of the uterus and the chorion, that provides for respiration and nourish- ment of the unborn child and the elimination of its metabolic wastes.

Question 10

umbilical cord

Answer 10

a soft tube containing blood vessels that connects the embryo to the placenta.

Question 11

neural tube

Answer 11

the primitive spinal cord that develops from the ectoderm and becomes the central nervous system.

Question 12

fetus

Answer 12

name given to the prenatal organism from the ninth week of pregnancy until birth.

Question 13

vernix

Answer 13

white, cheesy substance that covers the fetus to protect the skin from chapping.

Question 14

lanugo

Answer 14

fine hair covering the fetus’s body that helps vernix stick to the skin.

Question 15

age of viability

Answer 15

a point between the 22nd and 28th prenatal weeks when survival outside the uterus is possible.

Question 16

teratogens

Answer 16

external agents, such as viruses, drugs, chemicals, and radiation, that can harm a developing embryo or fetus.

Question 17

sensitive period

Answer 17

a period during which an organism is most susceptible to certain environmental influences; outside this period, the same environmental influences must be much stronger to produce comparable effects.

Question 18

rubella

Answer 18

a disease that has little effect on a mother but may cause a number of serious birth defects in unborn children who are exposed in the first three to four months of pregnancy.

Question 19

toxoplasmosis

Answer 19

disease caused by a parasite found in raw meat and cat feces; can cause birth defects if transmitted to an embryo in the first trimester and miscarriage later in pregnancy.

Question 20

thalidomide

Answer 20

a mild tranquillizer that, taken early in pregnancy, can produce a variety of malformations of the limbs, eyes, ears, and heart of the baby.

Question 21

diethylstilbestrol (DeS)

Answer 21

a synthetic hormone, formerly prescribed to prevent miscarriage, that can produce cervical cancer in adolescent female offspring and genital tract abnormalities in males.

Question 22

fetal alcohol spectrum disorder (FaSD)

Answer 22

term used to describe the full range of congenital problems commonly observed in the offspring of mothers who consumed alcohol during pregnancy.

Question 23

Cleft lip and palate

Answer 23

cleft lip:
a congenital disorder in which the upper lip has a vertical (or pair of vertical) opening or groove.
cleft palate:
a congenital disorder in which the roof of the mouth does not close properly during embryonic develop- ment, resulting in an opening or groove in the roof of the mouth.

Question 24

folate

Answer 24

B-complex vitamin that helps to prevent defects of the central nervous system.

Question 25

folic acid

Answer 25

synthetic version of folate.

Question 26

spina bifida

Answer 26

a bulging of the spinal cord through a gap in the spinal column.

Question 27

anencephaly

Answer 27

a birth defect in which the brain and neural tube fail to develop or develop incompletely and the skull does not close.

Question 28

neonate

Answer 28

a newborn infant from birth to approximately 1 month old.

Question 29

Stages of Labour

Answer 29

1. first stage of labour:
   the period of the birth process lasting from the first regular uterine contractions until the cervix is fully dilated.
2. second stage of labour: the period of the birth process during which the fetus moves through the birth canal and emerges from the mother’s body (also called delivery).
3. third stage of labour:
   expulsion of the placenta (afterbirth)

Question 30

engrossment

Answer 30

paternal analogue of maternal emotional bonding; term used to describe fathers’ fascination with their neonates, including their desire to touch, hold, caress, and talk to the newborn baby.

Question 31

anoxia

Answer 31

a lack of sufficient oxygen to the brain; may result in neurological damage or death.

Question 32

breech birth

Answer 32

a delivery in which the fetus emerges feet first or buttocks first rather than head first.

Question 33

respiratory distress syndrome

Answer 33

a serious condition (also called hyaline membrane disease) in which a preterm infant breathes very irregularly and is at risk of dying.

Question 34

primitive reflexes

Answer 34

reflexes controlled by subcortical areas of the brain that gradually disappear over the first year of life.

Question 35

autostimulation theory

Answer 35

theory proposing that REM sleep in infancy is a form of self-stimulation that helps the central nervous system develop.

Question 36

sudden infant death syndrome (SIDS)

Answer 36

unexplained death (also called crib death) of a sleeping infant who suddenly stops breathing.