i want 30  multiple choice questions with their model answer below each question that covers all of the following information: Folding of the embryo
Cephalocaudal folding
Lateral foldingFolding of the embryo
Amnion
Embryonic discCephalocaudal foldingLateral foldingCephalocaudal foldingLateral foldingCephalocaudal folding
Lateral folding
Sagittal section
Cross sectionCephalocaudal foldingCephalocaudal foldingLateral foldingLateral folding17 days
Cephalocaudal folding
Amniotic cavity
Connecting
stalk
Allantois
Yolk sac
Oropharyngeal
membrane
Cloacal
membrane22 days
The cephalocaudal
folding is due to the
lengthening of the
neural tube which
causes the head and
tail regions (folds) to
move ventrally.
Cephalocaudal folding
Amniotic cavity
Yolk sac
The embryo curves
into the fetal position.24 days
The cephalocaudal
folding is due to the
lengthening of the
neural tube which
causes the head and
tail regions (folds) to
move ventrally.
Cephalocaudal folding
Amniotic cavity
The embryo curves
into the fetal position.
Yolk
sac28 days
The cephalocaudal
folding is due to the
lengthening of the
neural tube which
causes the head and
tail regions (folds) to
move ventrally.
Cephalocaudal folding
Amniotic cavity
The embryo curves
into the fetal position.
Yolk
sacCephalocaudal folding
Fetal position17 days
Lateral folding
Amniotic cavity
Yolk sac17 days
The two lateral
body wall folds
move ventrally to
close the ventral
body wall.
Lateral folding
Amniotic cavity
Yolk sac20 days
The two lateral
body wall folds
move ventrally to
close the ventral
body wall.
Lateral folding
Amniotic cavity
Yolk sac21 days
The two lateral
body wall folds
move ventrally to
close the ventral
body wall.
Lateral folding
Amniotic cavity
Yolk sac24 days
The two lateral
body wall folds
move ventrally to
close the ventral
body wall.
Lateral folding
Amniotic cavity
Yolk
sac28 days
The two lateral
body wall folds
move ventrally to
close the ventral
body wall.
Lateral folding
Amniotic cavityResults of folding
The lateral
folding causes
the ventral body
wall to close
completely
except at the
umbilical region.
Ventral body wall
Amniotic cavity
EmbryoResults of folding
Failure of the
lateral folds to
close the body
wall causes the
ventral body
wall defects.Results of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavity
AmnionResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityResults of folding
During the
cephalocaudal and
lateral folding,
the head & tail and
two lateral folds
move ventrally and
they pull down the
amnion.
(The embryo lies
within the amniotic
cavity).
Amniotic cavityThe embryo
lies within the
amniotic cavity.
1- Embryo
2- Amniotic cavity
3- Chorionic cavity
4- Uterine cavity
5- Yolk sac
Results of folding
4
1
2
5
3
4The embryo
lies within the
amniotic cavity.
1- Embryo
2- Amniotic cavity
3- Chorionic cavity
4- Uterine cavity
5- Yolk sac
Results of folding
4
3 2
1
5Results of folding
Due to
cephalocaudal and
lateral folding
the connecting
stalk and allantois
move ventrally.
Connecting
stalk
AllantoisResults of folding
Due to
cephalocaudal and
lateral folding
the connecting
stalk and allantois
move ventrally.
Connecting
stalk
AllantoisResults of folding
Part of the
allantois is
incorporated
into the body of
the embryo.
The distal part
of the allantois
remains in the
connecting stalk.
AllantoisResults of folding
Due to
cephalocaudal and
lateral folding
large portion of the
endodermal germ
layer (Yolk sac) is
incorporated into
the body of the
embryo to form
the gut tube.
Yolk sacResults of folding Gut tube
Due to
cephalocaudal and
lateral folding
large portion of the
endodermal germ
layer (Yolk sac) is
incorporated into
the body of the
embryo to form
the gut tube.
Yolk
sacResults of folding Gut tube
Due to
cephalocaudal and
lateral folding
large portion of the
endodermal germ
layer (Yolk sac) is
incorporated into
the body of the
embryo to form
the gut tube.
Yolk
sacResults of folding
Due to
cephalocaudal and
lateral folding
large portion of the
endodermal germ
layer (Yolk sac) is
incorporated into
the body of the
embryo to form
the gut tube.
Yolk
sacResults of folding
Due to
cephalocaudal and
lateral folding
large portion of the
endodermal germ
layer (Yolk sac) is
incorporated into
the body of the
embryo to form
the gut tube (G).
G
Yolk
sacResults of folding
The gut tube:
1- Forgut
2- Midgut
3- Hindgut
1
2
3
Yolk
sacResults of folding
The midgut
communicates
with the yolk sac
by the vitelline
(yolk sac) duct.
The duct is wide
initially.
With growth of
the embryo, it
becomes narrow
and long.
Yolk
sac
Vitelline duct
Mid gutResults of folding
The midgut
Mid gut
communicates with the
yolk sac by the vitelline
(yolk sac) duct.
The duct is wide
initially.
With growth of the
embryo, it becomes
narrow and long.
By the fifth week
the umbilical region of
the embryo contains
the connecting stalk,
allantois, yolk sac duct,
and the blood vessels.
Yolk
sac
Vitelline ductThe Function of the yolk sac
-Formation of the gut
tube.
-Nutritive organ
(early stage).
-Site for formation of
the first blood cells.
-Site for formation of
germ cells.
Yolk
sacTubes of the embryo
Neural tube
During the third
and fourth weeks
the embryo
contains 2 tubes:
The
ectodermal
layer forms
the neural
tube
Dorsally.
The
endodermal
layer forms
the Gut tube
Ventrally.
Gut tubeThe oropharyngeal and
cloacal membranes
Cloacal membtrane
Oropharyngeal
membraneThe oropharyngeal and
cloacal membranes
In the 4th week, the
oropharyngeal membrane
ruptures to form the
opening of the oral cavity
(stomodeum).
In the 7th week the cloacal
membrane ruptures
to form the opening of the
anal canal.The derivatives of the endodermDerivatives of the endoderm
Parenchyma of the
liver and pancreas
Epithelial lining of
gastrointestinal tractDerivatives of the endoderm
Epithelial
lining of
respiratory
tract
Epithelial lining of urinary
bladder and urethraDerivatives of the endoderm
Parenchyma of the
thyroid and
parathyroids glands
Stroma of the
thymus glandDerivatives of the endoderm
Epithelial lining of the tympanic cavity and auditory tube
Stroma of the tonsils