Chapter 3 – Independent Questions
A. The Process of Conception (Optional reading: Not on the exams)
II. Pregnancy and Prenatal Development
A. The Mother’s Experience
1. The mother’s experience of pregnancy is divided into 3 equal parts or trimesters: (i) first
trimester: 0-12 weeks, (ii) second trimester: 13-24 weeks, (iii) third trimester: 25-38 weeks.
(a)You need to know the information summarized under the headings “Trimester”,
“Events” and “Serious Problems” (not “Prenatal Care”) in Table 3.1 (p. 62).
(b)You also need to know the information related to the italicized words on pp. 61-63 under
the subheadings “First Trimester”, “Second Trimester”, and “Third Trimester”.
- womb: women’s’ uterus
- cervix: the narrow, lower portion of the uterus, which extends into the vagina
- nausea and vomiting in pregnancy (NVP)/ morning sickness: feelings of nausea, often
accompanied by vomiting
- ectopic pregnancy: a zygote implants in one of the fallopian tubes instead of in the uterus
- spontaneous abortion: miscarriage
- gestational diabetes: kind of diabetes that happens only during pregnancy
- colostrum: secretion in women’s breast in preparation for nursing
- toxemia of pregnancy: sudden increase in blood pressure which can be life threatening or
cause a stroke
B. Prenatal Development
2. There are 2 patterns of physical growth in the developing fetus: cephalocaudal and
proximodistal patterns. Define each of these patterns of physical development.
cephalocaudal: growth that proceeds from the head downward
proximodistal: growth that proceeds from the middle/center of the body outward
3. There are 3 stages of prenatal development, which are defined by specific developmental
milestones. Unlike the mother’s experience, the three stages of prenatal development are
not equal in length. The first 2 weeks are referred to as the germinal stage; weeks 3-8 are
referred to as the embryonic stage; weeks 9-38 are referred to as the fetal stage.
(a) You need to know all of the information in Table 3.2. (Except the first sentence about
the average weight and length gains in the “Fetal Stage – Weeks 9-38”)
Germinal Stage (day 1: conception) : sperm and ovum unite, forming a zygote containing
genetic instructions for the development of a new and unique human being
(days 10 to 14: implantation): the zygote burrows into the lining of the uterus. Specialized cells
that will become the placenta, umbilical cord and embryo are already formed
Embryonic Stage ( weeks 3 to 8 : organogenesis): all the embryo’s organ systems form during
the 6 – week period following implantation
Fetal Stage (weeks 9 to 38: growth and organ refinement): by week 12, most fetuses can be
identified as male or female. Changes in brain and lungs make viability possible by week 24;
optimum development requires an additional 14 to 16 weeks in the womb. Most neurons form by
week 28, and connections among them begin to develop. The last 8 weeks, the fetus can hear and smell, is sensitive to touch, and responds to light. Learning is also possible.
(b)You also need to know the information related to the bold words on pp. 63-66 under the
subheadings “The Germinal Stage”, “The Embryonic Stage”, and “The Fetal Stage”.
- germinal stage: the first stage of prenatal development, beginning at conception and ending at
implantation (approx. 2 weeks)
- placenta: specialized organ that allows substances to be transferred from mother to embryo and
from embryo to mother without their blood mixing
- umbilical cord: organ that connects the embryo to the placenta
- amnion: fluid filled sac in which the fetus floats until just before it is born
- embryonic stage: 2 stage of prenatal development, from week 2 to 8, during which the
embryo’s organ systems form
- neurons: specialized cells of the nervous system
- gonads: sex glands (ovaries or testes)
- organogenesis: process of organ growth
- fetal stage: 3 stage , from week 9 to birth, during which growth and organ refinement take
- viability: ability of the fetus to su