Prenatal Development

Question 1

Ovulation

Answer 1

When a mature ovum is released from a woman’s ovary

Question 2

Fertilization

Answer 2

One of 300-500 sperm penetrates an ovum (Remember: sex is determined at conception and 107 to 170 males for every 100 females)

Question 3

Germinal Stage

Answer 3

Conception to 2 weeks; begins at conception; roughly 30 hours for one cell to become 2; 7-9 days after conception the cell implant in uterine lining; failure to implant results in a typical menstrual cycle

Question 4

Embryonic Stage

Answer 4

2 weeks to 2 months (end of 14 days to 2 months); 2 fetal membranes

Question 5

Organogenesis

Answer 5

Rapid development; week 2 - week 8 (2 weeks to 2 months); brain and nervous system develop (during 5th week production of neurons begins); heart begins to beat by 5-6 weeks; limbs appear; sex organs undifferentiated

Question 6

Amnion

Answer 6

Surrounds and cushions fetus (forms first); amniotic sac with fluid)

Question 7

Chorion

Answer 7

Placenta develops from this (surrounds amnion)

Question 8

Placenta

Answer 8

Brings oxygen and nutrients through umbilical cord and carries away waste from embryo (blood cells from mother never cross placental barrier)

Question 9

Embryonic disk

Answer 9

Embryonic disk forms three layers: ectoderm (exit, end), mesoderm (middle; muscles and heart), and endoderm (inner); cells on the inside of the blastocyst; will become the new organism

Question 10

Fetal Stage

Answer 10

9 weeks to Birth (start of the 3rd month); sexual differentiation; fetal breathing (~10 weeks-practice breathing); fetal movement; development of senses: cutaneous (touch and pain), chemical (taste and smell), vestibular (motion and balance), auditory, and visual; hiccups

Question 11

Fetus

Answer 11

The developing organism from the ninth week to the end of pregnancy- the period during which body structures are completed and dramatic growth in size occurs

Question 12

Zygote

Answer 12

The newly fertilized cell formed by the union of sperm and ovum at conception

Question 13

Blastocyst

Answer 13

Hollow, fluid-filled ball

Question 14

Trophoblast

Answer 14

Outer ring of cells; become the structures that provide protective covering and nourishment (protective outer layer)

Question 15

Growth pattern- proximodistal

Answer 15

Starts at center and moves outward

Question 16

Growth pattern- cephalocaudal

Answer 16

Head to tail (toe)

Question 17

Growth pattern- mass to specific

Answer 17

Generalized to more details

Question 18

Vernix

Answer 18

A white, cheese-like substance called vernix emerges on the skin, protecting to from chapping during the long months spent bathing in the amniotic fluid

Question 19

Lanugo

Answer 19

White, downy hair that covers the entire body of the fetus, helping the vernix stick to the skin

Question 20

Teratogen

Answer 20

Any environmental agent that causes damage during the prenatal period; examples are: alcohol, tobacco, prescription drugs (aspirin), and illegal drugs (cocaine and marijuana), radiation and environmental pollution, and maternal disease and stress

Question 21

Dilation

Answer 21

Becoming bigger and opens; cervix dilates to 10 cm (Columbia Doctors website)

Question 22

Effacement

Answer 22

Cervix stretches and gets thinner (Columbia Doctors website)

Question 23

APGAR scale

Answer 23

A rating system used to assess a newborn baby’s physical condition immediately after birth on the basis of characteristics at 1 minute and again at 5 minutes: heart rate, respiratory effort, reflex irritability muscle tone, and color (Score: 7 or better=good; 4-6=needs assistance; 3 or below= requires emergency medical attention