Deck 4: Organogenetic Period: the Fourth to Eighth Weeks

Question 1

______ Produces embryonic mesoderm

A)A
B)B
C)C
D)D
E)E

Answer 1

C
The primitive streak appears during the early part of the third week and produces mesoderm rapidly until the end of the fourth week.Thereafter,mesoderm production from this source slows down.

Question 2

________ Ectodermal depression in the neck

A)Limb bud
B)Neuropore
C)Septum transversum
D)Cervical sinus
E)Stomodeum

Answer 2

D
The cervical sinus is a depression in the surface ectoderm on each side of the future neck.It forms when the second pharyngeal arch overgrows the third and fourth arches.The second and third arches come to lie at the bottom of a pit-the cervical sinus.It is visible externally only during the fifth week.

Question 3

______ Cloaca

A)A
B)B
C)C
D)D
E)E

Answer 3

B
The cloaca is the dilated caudal part of the hindgut;the allantois enters it ventrally.The cloaca is separated from the amniotic cavity by the cloacal membrane.

Question 4

______ Amnion

A)A
B)B
C)C
D)D
E)E

Question 5

______ Separates the amniotic cavity from the foregut

A)A
B)B
C)C
D)D
E)E

Question 6

________ Optic groove in neural fold

A)A
B)B
C)C
D)D
E)E

Question 7

________ Outgrowth of the ventrolateral body wall

A)Limb bud
B)Neuropore
C)Septum transversum
D)Cervical sinus
E)Stomodeum

Question 8

________ Forms from the paraxial mesoderm

A)A
B)B
C)C
D)D
E)E

Question 9

______ Oropharyngeal membrane

A)A
B)B
C)C
D)D
E)E

Question 10

________ Hyoid arch

A)A
B)B
C)C
D)D
E)E

Question 11

______ Separates the amniotic cavity from the hindgut

A)A
B)B
C)C
D)D
E)E

Question 12

______ Part of the embryonic coelom

A)A
B)B
C)C
D)D
E)E

Question 13

________ Primordial mouth

A)Limb bud
B)Neuropore
C)Septum transversum
D)Cervical sinus
E)Stomodeum

Question 14

______ Second pharyngeal arch

A)A
B)B
C)C
D)D
E)E

Question 15

________ Closes during the fourth week

A)Limb bud
B)Neuropore
C)Septum transversum
D)Cervical sinus
E)Stomodeum

Question 16

________ Gives rise to the mandible

A)A
B)B
C)C
D)D
E)E

Question 17

______ Gives rise to a major part of the diaphragm

A)A
B)B
C)C
D)D
E)E

Question 18

______ Site of blood formation in the early embryo

A)A
B)B
C)C
D)D
E)E

Question 19

________ Neuropore

A)A
B)B
C)C
D)D
E)E

Question 20

________ Forms the major part of the diaphragm

A)Limb bud
B)Neuropore
C)Septum transversum
D)Cervical sinus
E)Stomodeum

Question 21

______ Will form the lower jaw

A)A
B)B
C)C
D)D
E)E

Question 22

______ Gives rise to the upper jaw

A)A
B)B
C)C
D)D
E)E

Question 23

______ Stomodeum

A)A
B)B
C)C
D)D
E)E

Question 24

______ Defect in its formation results in a severe type of spina bifida

A)A
B)B
C)C
D)D
E)E