問題一覧
1
What is the function of extraembryonic membranes in prenatal life?
They play a role in prenatal development.
2
When are the extraembryonic membranes expelled from the body?
Shortly after childbirth /during childbirth
3
In chickens, when does the yolk move into the abdominal cavity?
18-19 of incubation
4
How is the yolk sac connected to the embryonic body?
By the yolk stalk
5
What is formed when lateral mesoderm differentiation occurs?
Splanchnocoel
6
Which part of the mesoderm forms somatopleura/serosa/chorion?
Somatic mesoderm
7
What does splanchnopleura form in relation to the yolk sac?
Wall of the yolk sac
8
Why is the yolk sac referred to as the extraembryonic gut?
Its inner lining is covered with endoderm.
9
What are the initial groups of mesoderm cells called in the described process?
Blood islands
10
How do blood islands differentiate during the process?
They form irregular networks
11
What does the interconnected edge of blood islands form?
Endothelial layer
12
Where is the terminal sinus located, marking the boundary between areas?
Outside the embryo’s body
13
How do the blood vessels at the edge of the vascular area connect to each other?
Forming irregular networks
14
What marks the boundary between the vascular area and the vitelline area?
Terminal sinus
15
Where do the vitelline arteries branch from?
Dorsal aorta
16
How do the blood vessels outside the embryo’s body connect with the embryo’s blood vessels?
Via the vitelline veins
17
What happens to the central part of blood islands during differentiation?
It separates to form blood cell clusters
18
What role does the ductus venosus play in the connection of blood vessels?
Connects to the venous sinus
19
What distinguishes organisms possessing amnion (Amniota) from those without (Anamniota)?
Presence of extraembryonic membranes
20
How is the amnion sac formed in chickens during incubation?
Fusion of head, lateral, and tail folds
21
What is the function of the Ekamnion in the amnion sac?
Thickening the amniotic wall
22
How do mice and humans differ from chickens in amnion formation?
Through cavitation
23
How does the chorion in birds develop in relation to the somatopleura extraembryonic membrane?
It develops simultaneously as a fold of somatopleura
24
What is the chorion wall composed of in birds?
Inner layer from somatic mesodermma and Outer layer from trophoblast
25
In mammals, from which tissue does the chorion primarily originate during development?
Trophoblast
26
What role does the chorion play in the placenta formation process in mammals?
Is a part of the fetal placenta
27
In birds, which membrane is formed along with the chorion to create a structure essential for gas exchange?
Chorio-allantoic membrane
28
What is a notable feature of the chorion that facilitates gas exchange between maternal and fetal circulations?
Abundance of blood vessels
29
What cannot pass through the chorion membrane?
Bacteria
30
From where does the allantois originate in the developmental process?
ventro Medial evagination of the hindgut
31
What is the primary function of the allantois in reptiles, birds, and egg-laying mammals?
Digesting albumin in cleidoic egg yolk
32
In which animals is the chorio-allantoic membrane associated with the eggshell, allowing direct blood capillary connection to the external environment?
Reptiles and bird
33
At what stage of pregnancy do calcium deposits commonly appear in the chorio-allantoic membrane of cows?
Days 60 to 90
34
What is the structure formed by the amnion, yolk stalk, allantois, and splanknopleura as the embryo grows?
Umbilical cord
35
What is the region connecting the allantois to the hindgut called in vertebrates?
Allantoic stalk
36
From which structure does the allantois originate?
Hindgut
37
What is the outer layer of the allantois derived from?
Mesoderm
38
In reptiles and birds, the chorio-allantoic membrane is associated with what structure?
Eggshell
39
What is the function of the allantois as mentioned in the text?
Extraembryonic urine sac
40
What is the region connecting the allantois to the hindgut called?
Allantoic stalk
41
Cows
Fish
42
In vertebrates, what are the two respiratory regions mentioned in the text?
Gills and allantois
43
What is the structure formed by the amnion together with the yolk stalk, allantois, and splanknopleura?
Umbilical cord
44
What are the two layers that make up the wall of the chorion in birds?
Inner layer from somatic mesoderm and outer layer from trophoblast
45
In mammals, from which tissue does the chorion originate?
Trophoblast tissue
46
What is the role of the chorion in the placenta formation process in mammals?
Part of the fetal placenta
47
Why can’t bacteria pass through the chorion membrane?
Presence of trophoblast tissue
48
In humans, when do chorionic villi start forming during pregnancy?
Third day
49
What type of placenta is found in pigs and horses?
Diffuse placenta
50
What occurs during parturition in animals with a deciduate placenta?
Detachment of extraembryonic membrane
51
How is the placenta classified based on its shape in carnivores?
Zonary placenta
52
In uniparous animals, where does the umbilical cord lead from the fetus?
Minor curvature of the uterus
53
Which placental type allows direct contact between maternal and fetal blood vessels?
Hemochorial placenta
54
What is implantation?
The process of blastocyst embedding in the uterus
55
What plays an active role during implantation?
Blastocyst
56
What can cause implantation failure?
Synchronization between blastocyst and endometrium
57
What is the role of carbonic anhydrase during implantation?
Facilitates trophoblast attachment
58
In which animals can blastocysts experience a free-living phase before implantation?
All of the above
59
Why may efforts to increase offspring through superovulation face obstacles?
All of the above
60
What occurs during blastocyst migration in the uterus?
Transuterine migration
61
What changes does the uterus undergo during the progestational period?
Accumulation of nutrients in the uterine epithelium
62
What is the significance of the disappearance of the zona pellucida before implantation?
Facilitates trophoblast attachment
63
During which stage does blastocyst migration occur in monotocous mammals?
Pre-implantation
64
What is the primary factor determining the number of blastocysts implanted in a uterus?
Uterus volume capacity
65
Which animals lack caruncles, affecting the implantation process?
Pigs
66
What plays a primary role in determining pre-implantation changes in the uterus?
Progesterone
67
In animals with epitheliochorial or syndesmochorial placenta, when is histotroph crucial?
Throughout the pregnancy
68
What is the role of histotroph during the early stages of embryo development?
Providing nourishment for the embryo