Embryology Questions Flashcards
(184 cards)
1
Q
what is present in the 2nd week of development of the extraembryonic cavity?
A
exocoelomic cysts
2
Q
in IVF, what is used to stimulate ovaries?
A
Gonadotrophins
3
Q
On which day does the posterior neuropore close?
A
day 27
4
Q
which of the following are derived from the endoderm?
A
none of the following
5
Q
which embryonic layer is in contact with the parietal hypoblast?
A
Cytotrophobast
6
Q
which layer is generated by the epiblast?
A
epiblast
7
Q
which layers are the primary villi originated from?
A
cytotrophoblast
8
Q
what structure is under the neural tube?
A
notochord
9
Q
how long does semen capacitation take?
A
10 hours
10
Q
what is the placenta?
A
haemochoral
11
Q
what is the percentage of sperm in a sample?
A
14-90%
12
Q
on which day does the process of allantosis begin?
A
day 15-16
13
Q
when does the second meosis of oogenesis occur?
A
fertilisation
14
Q
at the eigth day of development, the hypoblast consists of
A
small cuboidal cells
15
Q
The amniotic cavity is formed by cells of the
A
epiblast
16
Q
approximately how long after fertilisation does the first cleavage of the zygote occur?
A
30 hours
17
Q
the primitive endothelial cells are formed by?
A
cells lining the yolk sac
18
Q
in the beginning of the third week, the paraxial mesoderm differentiates into segments known as
A
somites
19
Q
which embryonic layer is in direct contact with the parietal hypoblast until the formation of the extraembryonic mesoderm?
A
cytotrphoblast
20
Q
monozygous twins may have
A
common amnion, placenta and chorion
21
Q
the intraembryonic lateral plate mesoderm generates which of the following?
A
limb buds
22
Q
which of the statements regarding the types of spermatogonia is NOT true?
A
stem cells generating sertolli cells
23
Q
the number of oogonia at birth is approximately?
A
700,000-2,000000
24
Q
the primitive endothelial cells are formed by?
A
cell linings of the yolk sac
25
the amniotic and yolk sac cavities are temporarily connected by?
The neurenteric canal
26
the intraembryonic intermediate mesoderm forms?
gonads
27
from which germ layer do the adenohypophysis originate?
(anterior pituitary) surface ectoderm
28
which pharyngeal arch contributes to most of the middle eat ossicles
second
29
which cells are generated by the secondary spermatocytes?
early spermatids
30
what effect does prostaglandin have on the semen?
a+c
31
how does the female tract assist sperm migration?
b+c
32
which of the following statements is true?
chorionic villi are part of the foetal placenta part
33
the merging of which structures contributes to development of the face?
maxillary and mandibular processes and frontonasal prominence
34
from which component of the blastocyst can the stems capable of organ regeneration in humans?
embryoblast
35
which of the zona pellucida proteins acts as a receptor for spermatozoa binding?
ZP3
36
what is the name of the outer layer of the blastocyst?
trophoblast
37
the process of compaction of the pre-embryo leads to formation of an outer and inner cell mass, which differ in their intercellular junctions as follows:
outer cell mass--\> tight junctions---\> inner cell mass---\> gap junctions
38
from the 3rd month, hemopoiesis is
extravasal
39
the number of somites at the end of the 5th week of development is?
42-44
40
which of the following structures originates from the endoderm?
epithelium of vagina and prostate
41
which of the following stages is not a process of fertilisation?
gastrulation
42
which of the following phases of the menstrual cycle is under progesterone control?
secretory phase
43
primary villi result from the proliferation of?
cytotrophoblast
44
in which cavity are the exocoelomic cysts located during the second week of development?
extraembryonic cavity
45
how long after ejaculation is the maximum fertile time for most sperm?
48 hours
46
which of the following originates from the paraxial mesoderm?
dermis
47
the amniotic cavity is formed by cells of the?
epiblast
48
gastrulation begins with formation of the?
primitive streak
49
the following structires are NOT derived from the endoderm
all answers are true
50
how long does capacitation of the semen normally take\>
about 5-7 hours
51
the primitive endothelial cells are formed by?
cell linings of the yolk sac
52
trophoblastic overgrowth with lack of embryoblast development may lead to?
molar pregnancy
53
which pharyngeal arch contributes to the formation of the mandible?
first
54
what is the rate of occurrence of abnormal blastocysts?
20-30%
55
what is formed at the cranial end of the embryonic disk?
primitive knot
56
In the presence of how many cells generated by the zygote is the process of cleavage assumed to begin?
16
57
the following originate from the endoderm
urinary bladder, urethra, alimentary canal, liver, pancreas, trachea, bronchi, alveoli, throid, thymus, tympanic cavity
58
the conjoined monozygotic twins connected in the thoracic region are called?
thoracopagus
59
each somite differentiates into all the following
dermatomes, myotomes, syndetomes, sclerotomes
60
the bilaminar disk consists of?
epiblast and hypoblast
61
turner syndrome is
monosomy X(absence of an entire sex chromosome) resulting in 45 chromosomes
62
which germ layers do the nephrogenic cords originate from?
intermediate mesoderm
63
outermost layer of the embryonic mesoderm?
ectoderm
64
outermost layer of the preembryo
trophoblast
65
what are the two layers of the endometrium?
stratum functionalis and stratum basalis
66
time period within which the secondary oocyte can be fertilised
12-24 hours
67
how many cavities characterise the pre embryo at the end of the 2nd week of development
2(chorionic and amniotic)
68
the first blood cells originate from
yolk sac
69
what is the normal sperm count of the sperm in 1/ml?
15-40 million
70
which of the cells produce testosterone in the testis?
interstitial cells
71
which of the blastocyst poles is directed to the endometrium at implantation?
embryonic plate
72
the endoderm is crated by?
epiblast
73
during which stage of prophase of the first mitotic division in gametes does crossing over take place?
pachytene
74
what is the optimal window for people wishing to conceive a child?
3 days before ovulation and less than a day after
75
which structure is formed at the dorsal border of the neural tube?
spinal cord
76
the cells generated by the spermatogonia are?
primary spermatocytes
77
the cephalic end of the primitive streak is?
primitive node
78
which layer does the chorion originate from?
extraembryonic mesoderm
79
amniocentesis is used to investigate and detect?
prenatal diagnosis of chromosomal abnormalities and fetal genetic abnormalities
80
what is the name of the cells forming the morula?
blastomeres
81
when does implantation after fertilisation start?
6-7 days
82
how many chromosomes do fertilised eggs have?
46
83
what are the risks for pregnant women during a tubal pregnancy?
rupture, bleeding, internal haemorrhage
84
during the second week of development, the embryoblast differentiates into?
bilaminar germ disc composed of epiblast and hypoblast
85
what compartment of the blastocyst contributes to the formation of the placenta?
trophoblast
86
how long does it normally take the sperm to migrate in the female reproductive tract and to each the egg?
18-24 hours
87
which of the following lists are steps in in vitro fertilisation?
Ovarian hyperstimulation---(last) adjunctive medication
88
which of the following structures refer to embryonic membranes?
anmion, chorion, yolk sac, atlantosis
89
what is the average composition of seminal fluid?
2-5% sperm, 65-75% amino acids and citrate, 25-30% acid phosphatase, citric acid, 1% galactose and mucus
90
what is the average age of menopause in humans?
40 years
91
the somatopleure and splanchnopleure originate from
lateral mesoderm
92
which of the which germ layer do the heart and spleen originate from?
mesoderm
93
what is the name of the inner layer of the blastocyst?
hypoblast
94
what is the mechanism of the clonal expansion of the progenitors of the gametes?
mitosis
95
which of the listed options form the corona radiata?
granulosa cells
96
what is the main factor of sperm migration in the female reproductive tract?
sperm chemotaxis- progesterone
97
in which phase of the menstrual cycle does the endometrium achieve its maximum thickness?
luteal phase
98
the myotomes consist of?
epithelial somites
99
after its penetration in the oocyte, the spermatozoa head is transformed into?
pronucleus of zygote
100
the initial haemopoesis is
intravasal
101
the umbilical vein
carries oxygenated blood from placenta to foetus
102
which of the enumerated characteristics of given semen analysis are normal?
20 and 40 million sperm per mm
103
which of the following tissues originates from the endoderm?
lung, thyroid or pancreatic cells
104
cumulus oophorus is characteristic or which follicle?
antral follicles
105
the embryonic disk gradually becomes elongated with?
primitive streak
106
the process of cleavage represents a series of
mitotic cell divisions
107
gastrulation establishes
the trilaminar disc
108
which component of the preembryo aborts its development in a molar pregnancy?
hydatiform mole
109
the hypoblast belongs to
trophoblast
110
the formation of the fingers in the limb buds takes place via
apical ectodermal ridge
111
what is the correct sequence of the extended first meiotic division?
leptotene---(last)--synchronous processes
112
at which developmental stage does the segmentation of the paraxialmesoderm begin?
beginning of third week
113
which germ layer structure do the neurons of the peripheral nervous system originate from?
neural crest of ectoderm
114
how many pharyngeal arches contribute to the formation of the thymus?
3
115
the formation of the primitive streak occurs on the surface of
hypoblast
116
the connecting stalk originates from
extraembryonic medoderm
117
conjoined monozygotic twins by the head are called
craniophagus
118
which of the following phases of the menstrual cycle is under oestrogen control
follicular phase
119
ejaculation is identical to which process?
ovulation
120
the intervillus space of the placenta contains
blood(from the maternal arteries and veins
121
which compartment of the blastocyst contributes to the formation of the foetus?
embryoblast(inner cell mass)
122
the exocoelomic membrane lines the inner surface of?
cytotrophoblast
123
the secretion of FSH by the pituitary gland is suppressed by a factor secreted by the Sertoli cells called
inhibins
124
where must sperm normally encounter the egg in order to fertilise it?
ampulla of uterine/fallopian tube
125
how many pairs of chromosomes contain the primodial germ cells?
23
126
placental villi are best developed in the region of
syncytiotrophoblast
127
the rate of dizygotic twins is
70%
128
down syndrome is known as
trisomy 21
129
which germ layer do the serous membrane of the body originate from?
mesoderm(lateral plate?
130
which type of trophoblastic villi are formed in the 2nd week of development?
primary villi
131
name the most medially located components of the intraembryonic mesoderm
intermediate mesoderm
132
the inner layer of the embryoblast adjacent to the amniotic cavity is
epiblast
133
insemination is a process of passage of spermatozoa through the female genital tract as follows
deposition of sperm into ---\> migration to the uterus---\>uterine tube
134
which component of the preembryo continues to develop thus forming molar pregnancy?
trophoblast
135
the definitive umbilical cord contains
2 arteries and 1 vein
136
what is the normal sperm motility?
3mm/min
137
the cardiogenic primordium is formed by?
epiblast lateral to primitive streak
138
what is the sequence of appearance of the limb buds
flatten buds===\>radial grooves on distal portion of buds--\> digits
139
which requirements of the semen must be met for sperm motility?
increased flagellum motility, high no of mitochondria
140
The second meiotic division during oogenesis begins..
at the time of ovulation
141
From which germ layer develop the smooth muscle cells of internal organs?
Splanchnopleuric lateral plate mesoderm
142
Which layer of the preembryo is in direct contact with the endometrium?
Amnion
143
Which of the following tissues is derived from the ectoderm?
Adenohypophysis
144
Insemination is a process of passage of spermatozoa through the female genital tract as follows:
Vagina- cervix uteri- cavum uteri-uterine tubes
145
The heart and blood vessels are derivative of
lateral plate mesoderm
146
Which germ layer forms lacunae?
Syntiotrophoblast (cytotrophoblast + layer of syntiotrophoblast grow into lacunae)
147
The olfactory placode is located on the surface of which structure?
Frontonasal prominence
148
What is the inner mucus layer of the uterus called?
Endometrium
149
From which germ layer, originate the nephrogenic cords?
Intermediate germ layer
150
Which of the listed structures penetrate deepest into the endometrium?
Tertiary Villi
151
The formation of the notochord occurs during?
3rd Week
152
Teratogens are agents that?
cause congenital malfunction
153
Which of the following do not originate from the endoderm?
heart and blood vessels
154
gastrulation is established...
Ectoderm, mesoderm, endoderm( single layered blastula is reorganised into a multi-layered structure known as the gastrula)
155
Which structures originate from the lateral plate and mesoderm?
Epithelium of the peritoneal, pleural and pericardial cavities
156
Which components of the seminal fluid contribute to the raising of the pH from 3.5-7.5 and activating the sperm?
Seminal vesicle fluid
157
During the process of cleavage..
The cells do not change size
158
Sclerotomes differentiate into..
Bone and cartilage which surround the notochord
159
Which cells of the spermatogonic population have bivalent chromosomes?
spermatids
160
In which cells are the cortical granules located?
Oocyte(peripheral cytoplasm)
161
The preimplantation genetic diagnosis represents analysis of?
blastomeres
162
Name the medially located compartment of the intraembryonic mesoderm
Paraxial mesoderm
163
Which Structures originate from the lateral plate mesoderm?
Epithelium of the renal tubes and renal calices
164
What is the volume of seminal fluid in a healthy individual?
0.5-1ml
165
which of the listed options is associated with the acrosomal reaction of the spermatozoa?
all answers are true
166
Which techniques of artificial insemination are available to the public?
a and c
167
each somite differentiates into the following except..
Nephrotome
168
At which embryonic stage are the endocardial heart tubes formed?
day 19
169
Chromosomal aberations(trisomy/monosomy) are most frequently due to..
Non disjunction of homologous chromosomes during first meiotic division
170
The notochord serves as a basis for
The axial skeleton
171
The definitive umbilical cord contains
mucous connective tissue( warton's jelly)
172
Which structures do the exocoelomic cavities(cysts) arise from in the 2nd week of development?
secondary yolk sac
173
Which of the following are functions of the yolk sac?
takes part in early blood circulation
174
The process of cleavage(segmentation) is?
mitosis
175
gastrulation occurs in the beginning of the....
third week
176
The umbilical arteries...
surround the urinary bladder
177
Which of the following tissues is derived from the ectoderm?
Epidermis skin cells, neurons of brain and pigment cells
178
When does implantation after fertilization еnd?
13-14 days
179
Which layer is in contact with the cytotrophoblast after the formation of the extraembryonic cavity
Extraembryonic somatopleuric mesoderm
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