Fertilization & Development Flashcards
(107 cards)
1
Q
3 Periods
A
Germinal stage, Embryonic period, and Fetal period
2
Q
First 2 weeks of fertilization
A
Germinal stage
3
Q
A complex multi-step process that is complete within 24 hours
A
Fertilization
4
Q
The fertilization takes place in…
A
Fallopian tube
5
Q
This links an ovary to the uterus
A
Fallopian tube
6
Q
It takes about ___-___ for the sperm to reach the egg
A
30 - 45 minutes
7
Q
Phase in the menstrual cycle when the ovary releases an egg (ovum)
A
Ovulation
8
Q
Ovulation happens on day ____ of a 28-day menstrual cycle
A
Day 14
9
Q
Estrogen levels rise as a result of increased estrogen production by hormonally active granulosa cells within the follicle
A
Notes lang ito
10
Q
After ovulation, the egg is capable of fertilization for only 12 to 24 hours
A
Notes
11
Q
Sperm can remain within the female reproductive tract for
A
5 days
12
Q
To fertilize an egg, sperm must penetrate the __________ and the ___________
A
- corona radiata (granulosa cells)
- zona pellucida
13
Q
What is the glycoprotein layer outside of the oocyte’s plasma membrane
A
Zona pellucida
14
Q
1mL of sperm normally contains 100 million sperm
A
True
15
Q
Receptor for the sperm in the zona pellucida
A
Glycoprotein ZP3
16
Q
After fertilization (at about 24 hours), the zygote begins mitotic division called _______. The first division takes about _______. Successive divisions take less time
A
- Cleavage
- 6 hours
17
Q
By the second day after fertilization, a second cleavage is completed yielding _____
A
4 cells
18
Q
By the end of the______ there are 16 cells. Each division yields smaller and smaller cells (blastomeres).
A
- Third day
19
Q
By the fourth day the cluster of cells resembles a mulberry and is called a ______. It is still surrounded by the zona pellucida and is still the size of the zygote.
A
- Morula
20
Q
On day 4 or 5, the morula enters the uterine cavity and is nourished by uterine milk, a glycogen-rich secretion from endometrial glands in addition to stored nutrients from the cytoplasm.
A
Notes
21
Q
Occurs when a fertilized egg grows outside the uterus
A
Ectopic pregnancy
22
Q
At the 32-cell stage (Day 5), the fluid now inside the morula, rearranges the blastomeres into a large, fluid filled blastocyst cavity (blastocoel). The mass is now called a _______
A
Blastocyst
23
Q
2 different populations arose when blastocyst is formed.
The __________ (inner cell mass) will develop
into the embryo.
The __________ (outer cell mass) will develop
into the outer chorionic sac surrounding the
fetus, and the fetal portion of the placenta.
A
- Embryoblast
- Trophoblast
24
Q
The blastocyst remains free in the uterine cavity for about 2 days and then implants by attaching to the endometrium at around 6 days after fertilization.
A
Notes: When the blastocyst is attached to the endometrium, implantation occurs.
25
True or false:
Implantation usually occurs in either the anterior portion of the fundus or the body of the uterus.
False. It occurs in the "posterior" portion of the fundus
26
True or false:
The outer cell mass orients toward the endometrium
False. The "inner" cell mass orients toward the endometrium
27
After implantation, the endometrium is called the ________.
Decidua
28
About 8 days after implantation, the trophoblast develops into the ____________ and _________.
A. Embryoblast and blastocytes
B. Embryblast and trophoblast
C. Hypoblast and epiblast
D. Syncytiotrophoblast and cytotrophoblast
D. Syncytiotrophoblast and cytotrophoblast
29
At around 8 days, the embryoblast also develops into two layers: _____________ and __________
A. Embryoblast and blastocytes
B. Embryblast and trophoblast
C. Hypoblast and epiblast
D. Syncytiotrophoblast and cytotrophoblast
C. Hypoblast and epiblast
30
Hypoblast means
Primitive endoderm
31
Epiblast means
Primitive ectoderm
32
It surrounds the entire embryo
Amniotic fluid
33
Also on the 8th day, the exocoelomic membrane forms that, together with the hypoblast forms the _________
On the 9th day, small spaces called ________
By the ______ day, they fuse to form _________
1. Yolk sac
2. Lacunae form
3. 12th day
4. Lacunar networks
34
About the 12th day after fertilization, the
extraembryonic mesoderm develops.
The extraembryonic mesoderm together with the trophoblast forms the chorion which surrounds the embryo and, later, the fetus.
Notes
35
Hormone typically found in identifying pregnancy
Human chorionic gonadotropin (hCG)
36
The chorion:
○ Blocks antibody production by the mother
○ Promotes production of T lymphocytes to
suppress the immune response in the uterus
○ Produces human chorionic gonadotropin (hCG)
Notes :)) basahin :)) mo :))
37
The first major event of the 3rd week of development is ?!
Gastrulation!
38
The two-layered embryonic disc transforms into a trilaminar (three-layered) embryonic disc which are:
Ectoderm, mesoderm, endoderm
39
True or false:
Gastrulation is associated with the rearrangement and migration of cells from the hypoblast
False: It is from the epiblast
40
The first step in gastrulation is formation of the _________
A. Primitive streak
B. Primitive node
C. Embryonic disc
D. Notochord
A. Primitive streak
41
It establishes the head and tail ends of
the embryo.
Primitive streak
42
After the cells of the epiblast move inward below the primitive streak and undergo what?
Invagination (process of being turned inside out or folded back)
43
Identify: Endoderm, mesoderm, Ectoderm
1. Epithelial lining of urinary bladder
2. Epidermis of skin
3. Epithelium of oral cavity
4. Muscle
5. Kidneys
1. Epithelial lining of urinary bladder - Endoderm
2. Epidermis of skin - Ectoderm
3. Epithelium of oral cavity - Ectoderm
4. Muscle - Mesoderm
5. Kidneys - Mesoderm
44
About 16 days after fertilization, the notochordal process forms.
By days 22–24, the process becomes the solid cylinder called the notochord.
The notochord is important for induction, the process whereby the inducing tissue stimulates development of a responding tissue to develop into a specific structure.
The notochord induces the development of vertebral bodies and the nucleus pulposus of the vertebral discs
Notes
45
During the 3rd week of development, the following structures form:
○ Oropharyngeal membrane
○ Cloacal membrane
○ Allantois
ok
46
This facilitates gas exchange and serves as a storage site for waste products from the developing fetus
Allantois
47
This induces development of the neural
plate.
Notochord
48
The plate develops this when the lateral edges become more elevated
Neural fold
49
The depressed mid region of the fold is the __________.
Neural groove
50
It is formed when the neural folds approach each other and fuse
Neural tube
51
The process of formation of neural fold, groove, and tube is called
Neurulation
52
As the neural tube forms, some of the ectodermal cells from the tube migrate to form several layers of cells called the
Neural crest
53
At about 4 weeks after fertilization, the head end of the neural tube develops into three enlarged areas called
Primary brain vesicles
54
Primary brain vesicles:
1. Mesencephalon (Midbrain)
2. Rhombencephalon (Hindbrain)
3. Prosencephalon (Forebrain)
Notes
55
Subdivision of Prosencephalon (forebrain):
Telencephalon and Diencephalon
56
Structures in the Forebrain—Telencephalon:
Cerebral hemisphere, basal ganglia, hippocampus
57
Structures in the Forebrain—Diencephalon:
Thalamus, hypothalamus, pineal body, infundibulum
58
Structures in the Mesencephalon:
Tectum, tegementum, crus cerebri
59
Structures in the Hindbrain—Myelencephalon:
Medulla oblongata
60
Structures in the Hindbrain—Metencephalon:
Pons, cerebellum
61
Subdivision in the Forebrain:
Diencephalon and Telencephalon
62
By about the 17th day after fertilization, paired, cube-shaped structures called somites form.
By the end of the 5th week, 42–44 pairs are present.
Each somite differentiates into a myotome, dermatome, and sclerotome.
notes
63
A strip of skin supplied by a single nerve
Dermatome
64
A muscle/ group of muscles supplied by a
single nerve.
Myotome
65
What week does the formation of blood vessels (angiogenesis) begins? Blood islands causes the blood vessels to form
At the beginning of the 3rd week
66
On days 18 and 19, the heart begins to develop in the head end of the embryo. It begins in a region of mesodermal cells called the cardiogenic area.
Notes
67
The process of forming the placenta.
Placentation
68
This structure is the site of exchange of nutrients and wastes between the mother and fetus.
Placenta
69
Blood circulation in placenta:
Maternal-placental (uteroplacental) & fetal-placental (fetoplacental)
70
By the beginning of the 12th week, the placenta has two parts:
○ The fetal portion (chorionic villi)
○ The maternal portion (decidua basalis of the endometrium)
Notes
71
All major organs develop between the _____ to ________ (organogenesis).
4th through 8th weeks
72
Embryonic folding occurs during the 4th week.
This involves the flat embryo folding into a three-dimensional cylinder.
Five pairs of pharyngeal arches (branchial arches) also develop on each side of the future head and neck regions during the 4th week. Each arch is separated by a pharyngeal cleft.
notes
73
By the middle of the 4th week, ___________ begins to develop.
upper limb buds
74
By the end of the 4th week, ___________ and __________ form.
lower limb buds and heart prominence
75
The embryo has a tail at what week?
At the end of the 4th week
76
During the 5th week, ________ and ________ develop rapidly and the limbs develop further.
the brain and head
77
What week the regions of the limbs become distinct and digits appear.
A. 8th week
B. 5th-6th week
C. 10th week
D. 7th week
D. 7th week
78
What week does the eyelids come together, the tail disappears, external genitals begin to differentiate and digits are distinct and are no longer webbed.
A. 8th week
B. 5th-6th week
C. 10th week
D. 7th week
A. 8th week
79
The fetal period begins at the ____________ after fertilization.
9th week
80
True or false:
Tissues and organs that developed during the embryonic period grow and differentiate.
True
81
Limbs become distinct and digits disappear
A. 5 - 8 weeks
B. 9 -12 weeks
C. 1 - 4 weeks
D. 12th weeks
A. 5 - 8 weeks
82
Heart forms and begins to beat
A. 5 - 8 weeks
B. 9 -12 weeks
C. 1 - 4 weeks
D. 12th weeks
C. 1 - 4 weeks
83
Face is more humanlike
A. 5 - 8 weeks
B. 9 -12 weeks
C. 1 - 4 weeks
D. 12th weeks
A. 5 - 8 weeks
84
Heart becomes four-chambered
A. 5 - 8 weeks
B. 9 -12 weeks
C. 1 - 4 weeks
D. 12th weeks
A. 5 - 8 weeks
85
Nose develops and is flat
A. 5 - 8 weeks
B. 9 -12 weeks
C. 1 - 4 weeks
D. 12th weeks
A. 5 - 8 weeks
86
Face is broad , with eyes fully developed, closed, and widely separated
A. 5 - 8 weeks
B. 9 - 12 weeks
C. 13 - 16 weeks
D. 17 - 20 weeks
B. 9 -12 weeks
87
Gender is distinguishable from external genitals
A. 5 - 8 weeks
B. 9 -12 weeks
C. 13 - 16 weeks
D. 17 - 20 weeks
B. 9 -12 weeks
88
Nose develops a bridge
A. 5 - 8 weeks
B. 9 -12 weeks
C. 13 - 16 weeks
D. 17 - 20 weeks
B. 9 -12 weeks
89
Head constitutes about half the length of the body
A. 5 - 8 weeks
B. 9 -12 weeks
C. 13 - 16 weeks
D. 17 - 20 weeks
B. 9 -12 weeks
90
Head is relatively smaller than the rest of the body
A. 21 - 25 weeks
B. 9 -12 weeks
C. 13 - 16 weeks
D. 17 - 20 weeks
E. 5 - 8 weeks
C. 13 - 16 weeks
91
Fetus is even more humanlike
A. 21 - 25 weeks
B. 9 -12 weeks
C. 13 - 16 weeks
D. 17 - 20 weeks
E. 5 - 8 weeks
C. 13 - 16 weeks
92
The head is more proportionate to the rest of the body
A. 21 - 25 weeks
B. 17 - 20 weeks
C. 13 - 16 weeks
D. 9 - 12 weeks
E. 5 - 8 weeks
B. 17 - 20 weeks
93
Fetal movements are commonly felt by mother (quickening)
A. 21 - 25 weeks
B. 17 - 20 weeks
C. 13 - 16 weeks
D. 9 - 12 weeks
E. 5 - 8 weeks
B. 17 - 20 weeks
94
Eyebrows and head hair are visible
A. 21 - 25 weeks
B. 17 - 20 weeks
C. 13 - 16 weeks
D. 9 - 12 weeks
E. 5 - 8 weeks
B. 17 - 20 weeks
95
Skin is pink and wrinkled
A. 30 - 34 weeks
B. 17 - 20 weeks
C. 13 - 16 weeks
D. 21 - 25 weeks
D. 21 - 25 weeks
96
Fetuses 24 weeks and older usually survive if born prematurely
A. 30 - 34 weeks
B. 17 - 20 weeks
C. 13 - 16 weeks
D. 21 - 25 weeks
D. 21 - 25 weeks
97
Weight gain is substantial
A. 30 - 34 weeks
B. 17 - 20 weeks
C. 13 - 16 weeks
D. 21 - 25 weeks
D. 21 - 25 weeks
98
Head becomes even more proportionate to rest of body
A. 30 - 34 weeks
B. 17 - 20 weeks
C. 13 - 16 weeks
D. 21 - 25 weeks
D. 21 - 25 weeks
99
Eyes are open
A. 30 - 34 weeks
B. 26 - 29 weeks
C. 13 - 16 weeks
D. 21 - 25 weeks
B. 26 - 29 weeks
100
Toenails are visible
A. 30 - 34 weeks
B. 26 - 29 weeks
C. 35 - 38 weeks
D. 21 - 25 weeks
B. 26 - 29 week
101
Many fetuses born prematurely during this period survive if given intensive care
A. 30 - 34 weeks
B. 26 - 29 weeks
C. 35 - 38 weeks
D. 21 - 25 weeks
B. 26 - 29 weeks
102
Skin is pink and smooth
A. 30 - 34 weeks
B. 17 - 20 weeks
C. 35 - 38 weeks
D. 21 - 25 weeks
A. 30 - 34 weeks
103
Fetus assumes upside-down position
A. 30 - 34 weeks
B. 35 - 38 weeks
C. 13 - 16 weeks
D. 21 - 25 weeks
A. 30 - 34 weeks
104
Body fat is 8% of total body mass
A. 30 - 34 weeks
B. 17 - 20 weeks
C. 35 - 38 weeks
D. 21 - 25 weeks
A. 30 - 34 weeks
105
Skin is usually bluish-pink
A. 30 - 34 weeks
B. 17 - 20 weeks
C. 35 - 38 weeks
D. 21 - 25 weeks
C. 35 - 38 weeks
106
Testes are usually in scrotum in full-term male infants
A. 30 - 34 weeks
B. 26 - 29 weeks
C. 35 - 38 weeks
D. 21 - 25 weeks
C. 35 - 38 weeks
107
Testes begins to descend toward scrotum
A. 30 - 34 weeks
B. 26 - 29 weeks
C. 35 - 38 weeks
D. 21 - 25 weeks
B. 26 - 29 weeks
