Exam 1.2

the embryonic ectoderm is subdivided into _____ domains:

4

• ectodermal ectoderm

• CNS

• neural crest cells

• cranial plates

neurulation

formation of the neural plate

derivatives formed by neural crest cells migrating out of the neural plate area

primary vesicles has _____ parts:

3 (rostral to caudal)

• forebrain/prosencephalon

• midbrain/mesencephalon

• hindbrain/rhombencephalon

forebrain aka

prosencephalon

midbrain aka

mesencephalon

hindbrain aka

rhombencephalon

there are ______secondary vesicles:

5 (rostral to caudal)

• telencephalon

• diencephalon

• mesencephalon

• metencephalon

• myelencephalon

what parts of the secondary vesicles does the prosencephalon of the primary vesicles subdivide into

telencephalon and diencephalon

what parts of the secondary vesicles does the mesencephalon of the primary vesicles subdivide into

does not subdivide at all, remains the mesencephalon

what parts of the secondary vesicles does the rhombencephalon of the primary vesicles subdivide into

metencephalon and myelencephalon

see the adult derivatives of certain parts of the secondary vesicles

how long does it take for the primary brain vesicles to become distinguishable by?

33 hrs

• at this pt, the anterior part of the neural tube has 3 distinct regions (the 3 primary vesicle parts)

at 33 hrs the embryo is____

the embryo is flat

how long does it take for the secondary brain vesicles to become distinguishable

48 hrs

at 48 hrs, the embryo starts to

twist into its side

by ___ hrs the secondary vesicles are even more elaborated and the embryo has twisted even more

72 hrs

once you see eye structures in your cross-sections, you are in which regions

prosencephalon when at 33hrs

diencephalon at 48+ hrs

what makes older stage cross-sections tricky?

the curvature of the embryo makes it so that some cross-sections will show multiple axial levels at once, and diff slide sets have axial cuts at diff angles