Chapter 12: Conception and Prenatal Development Flashcards
1
Q
What is the pre-embryonic period?
A
First 2 weeks after conception
2
Q
How long can sperm live in the woman’s reproductive tract?
A
Most 1-2 days
Few up to 80 hours
3
Q
Four patterns of prenatal growth and development
A
- cephalocaudal (head to toe)
- central to peripheral
- simple to complex
- general to specific
4
Q
Decidual layer of placenta that underlies the developing embryo and forms the maternal side of the placenta
A
decidua basalis
5
Q
Fertilization age in which skin is translucent
A
weeks 21-24
6
Q
In the pre-embryonic period, nutrition to the embryo occurs via ___________
A
diffusion
7
Q
Full term gestational age
A
38-42 weeks
8
Q
Fertilization age in which implantation is complete
A
week 2
9
Q
The secretion of hCG allows the ___________ to secrete estrogen and progesterone until the placenta takes over
A
corpus luteum
10
Q
The (fetal, maternal) side of the placenta is rough where it attaches to the uterus
A
maternal
11
Q
Fertilization age in which the heart is prominent and reaches the final four-chambered form
A
week 6
12
Q
Fertilization age in which the heart is in early development
A
week 3
13
Q
During implantation, a small amount of ____________ may occur
A
bleeding
14
Q
How is the passage of maternal IgG antibodies beneficial to the fetus?
A
provides temporary immunity
15
Q
two functions of progesterone in pregnancy
A
- changes endometrium into decidua, providing nourishment for early conceptus
- reduces uterine contractions and suppresses maternal reactions to fetal antigens to prevent spontaneous abortion
16
Q
age since conception
A
fertilization age
17
Q
Development of specialized structures is controlled by these three factors
A
- genetics
- interaction between adjacent tissues
- timing
18
Q
Term in which fetal movements are felt by the mother
A
quickening
19
Q
Fertilization age in which growth continues but growth slows
A
weeks 33-38
20
Q
Term for endometrium after implantation
A
decidua
21
Q
Term for fertilized ovum
A
conceptus
22
Q
Fertilization age in which the embryo has a definite human form with continuing system refinement
A
week 8
23
Q
Fertilization age in which the CNS begins to develop
A
week 3
24
Q
Nutrition is provided by the _________________ until nidation
A
conceptus ball
25
Environmental agents that may cause damage (especially vulnerable during embryonic period)
teratogens
26
two functions of hCG
1. corpus luteum persistence
2. secretion of estrogen and progesterone in first 6-8 weeks
27
The outer cells of the morula create the ___________
blastocyst
28
Decidual layer of the placenta which lines the remainder of the uterine cavity
decidua parietalis
29
A low hCG level in a woman who thinks she is pregnant will likely result in ______________. Why?
miscarriage
The corpus luteum will not continue to secrete estrogen and progesterone because the zygote has not secreted enough hCG to maintain a pregnancy.
30
circulatory shunt that is a hole between the right and left atria
foramen ovale
31
fraternal twins are termed _____________
dizygotic
32
Term for largest portion of fallopian tube
ampulla
33
Fertilization age in which external genitalia begin to differentiate (but not yet distinct)
week 8
34
Continued development is dependent upon __________
nidation
35
fatty, cheese-like secretion of fetal sebaceous glands that protects skin from constant exposure to amniotic fluid
vernix caseosa
36
How do relative fetal and maternal blood carbon dioxide levels allow the fetus to survive in a low-oxygen environment?
More alkaline (more CO2) fetal blood and more acidic (less CO2) maternal blood allows mother's blood to give up O2 and fetal blood to combine readily with O2
37
Oogenesis begins during ____________
prenatal life
38
(Early, Advanced) maternal age at increased risk of multifetal pregnancies
Advanced
39
The embryonic period takes place from _____________ through __________ after conception (fertilization age)
beginning of 3rd week, end of 8th week
40
two protection functions of amniotic fluid
1. cushion against impact
2. provides stable temperature
41
Fertilization age in which the four chamber heart BEGINS
week 4
42
Fertilization age in which blood formation is primarily in the liver
week 6
43
Fertilization age in which early heart begins beating
21-22 days (week 5)
44
three functions of estrogen in pregnancy
1. enlargement of uterus, breasts, and external genitalia
2. growth of breast ductal system
3. enhances uterine activity as labor begins
45
Fertilization age in which the fetus has more subcutaneous fat
weeks 29-32
46
Term for inner fetal membrane
amnion
47
Spermatogenesis begins during ___________
puberty (in males)
48
Fertilization age in which blood formation shifts to the bone marrow
weeks 25-28
49
Gestational period in which basic structures of all major body organs are completed
embryonic period
50
Location where exchange of substances between mother and fetus occurs (150 mL of blood is temporarily outside the maternal circulation)
intervillous space of the placenta (between arteries and umbilical cord)
51
Part of the outer layer of cells of the blastocyst develops into the ____________
placenta
52
heat-producing fat that maintains temperature stability after birth
brown fat
53
Complete implantation gradually occurs between days ____ and ____; _______________ continue to develop
6, 10; embryonic structures
54
stages of fetal circulation (11 steps)
umbilical vein--> ductus venosus--> inferior vena cava--> right atrium--> foramen ovale--> left atrium--> left ventricle--> lungs (nutrition)--> ductus arteriosus--> aorta--> head and extremities
55
two ways that fetal hemoglobin and hematocrit allows fetus to thrive in low-oxygen environment
1. Hgb can carry 20-50% more oxygen
2. higher average levels of both
56
three development functions of amniotic fluid
1. allows symmetric development
2. prevents membranes adhering to fetal parts
3. provides room and buoyancy for movement
57
fine, downy hair covering fetal body to help vernix attach to skin
lanugo
58
Fertilization age in which fingers and toes are well defined
week 8
59
Full term conception (fertilization) age
36-40 weeks
60
The conceptus enters the uterus approximately ___________ after conception
3-4 days
61
When do primary oocytes complete their first meiotic division (resulting in a secondary oocyte)?
Shortly before ovulation
62
Term for outer fetal membrane
chorion
63
Fertilization age in which movements strengthen and may be felt by mother
weeks 13-16
64
How is the passage of maternal IgG antibodies harmful to the fetus?
This may occur if the Rh factor is positive in fetus and negative in mother. The mother's antibodies can destroy fetal erythrocytes.
65
Fertilization age in which the lungs begin to produce surfactant
week 24
66
surface-active lipid that eases breathing after birth and prevents alveoli collapse
surfactant
67
circulatory shunt that bypasses the lungs
ductus arteriosus
68
Decidual layer of placenta which overlies the embryo and bulges into the uterine cavity as the embryo and fetus grow
decidua capsularis
69
Fertilization age which begins with large head but body starts to grow faster
weeks 9-12
70
Another term for implantation
nidation
71
Females have all ova by __________
30 weeks (gestation)
72
Fertilization age in which the head is large due to rapid brain growth
week 5
73
circulatory shunt that bypasses the liver
ductus venosus
74
Term for zygote with 12-16 cells
morula
75
Fertilization age in which blood formation shifts to the spleen
weeks 10-12
76
identical twins are termed ___________
monozygotic
77
Fertilization age in which the beating heart can be seen in a transvaginal ultrasound
week 6
78
The inner cell mass of the blastocyst develops into the _________
fetus
79
The zygote secretes _______ to signal that a pregnancy has begun
hCG (human chorionic gonadotropin)
80
The (fetal, maternal) side of the placenta is smooth with branching vessels covering the membrane-covered surface
fetal
81
Fertilization age in which the neural tube completes closure (spina bifida is possible if does not close)
week 4
82
What is necessary for the second meiotic division of oogenesis to be completed?
Fertilization
83
Fertilization age in which growth and refinement of all systems occur
week 7
84
age based on last menstrual period
gestational age
85
Ideal location in uterus for implantation and three reasons why
Fundus of uterus
1. richly supplied with blood for optimal gas exchange and nutrition
2. thick lining prevents deep placenta attachment
3. limits blood loss after birth
86
function of corpus luteum
maintains high estrogen and progesterone secretion to prepare uterine lining for fertilized ovum
87
Implantation and survival of the zygote depends on the continuous supply of _____________ and _____________
estrogen, progesterone
88
Fertilization age in which embryonic disk develops germ layers
week 3
89
Fertilization age in which the vernix caseosa, lanugo, and brown fat develop
weeks 17-20
90
How long does the mature ovum survive (and have the ability to be fertilized)?
24 hours
91
Fertilization age in which the fetus usually moves to a head-down position
weeks 25-28
92
When does the secondary oocyte divide to form a mature ovum?
At ovulation
93
Fertilization age in which the eyes, ears, and nose are widely separated
week 6
94
Fertilization age in which the embryo resembles a C shape
week 4
95
After the conceptus enters the uterus, it lingers in the uterus for about __________ before implantation
2-4 days
96
four functions of human chorionic somatomammotropin (formerly human placental lactogen or hPL)
1. promotes normal nutrition and growth of fetus
2. promotes maternal breast development for lactation
3. decreases maternal insulin sensitivity
4. decreases utilization of glucose (makes more glucose available for fetal growth)
97
Fertilization age in which fetus moves but mother cannot feel
weeks 9-12
