Embry 2 Flashcards
What are the 3 roles of the notochord
- establishes the longitudinal axis of the embryo and gives it some rigidity
- provides signals for the development of axial MSK structures and the CNS
- contributes to the intervertebral discs
mesenchymal cells dive into the primitive pit and migrate cephalad, they form a cord called what?
notochordal process
the notochordal process develops a lumen known as the ?
notochordal canal
after the notochordal process approaches the prechordal plate, the floor of the process “fuses” with the ?. The notochordal process is now the ?
endoderm
notochordal plate
notochordal plate -> notochord transition starts
cranially and progresses caudally
the notochord induce the overlying ectoderm to develop into the ?
neural plate
the prechordal plate develops into the ?
oropharyngeal membrane
the oropharyngeal membrane has how many layer membrane?
ectoderm and endoderm, no mesoderm
What forms caudal to the primitive streak
cloacal membrane
how many layers are in the cloacal membrane?
two layers - ectoderm and endoderm, no mesoderm
what is the future site of the anus
cloacal membrane
what is allantois and what does it do?
small, vascularized diverticulum from the caudal wall of umbilical vesicle, extending into the connecting stalk
- functions in early blood formation and bladder develop, blood vessels become umbilical arteries
notochord induces overlying ectoderm to form the ?
neural plate also known as neuroectoderm
on day 18, the neural plate invaginates to form ?
the neural groove - neural folds are found on either side of the groove
the neural folds eventually fuse together, and form the ?
neural tube
what is neurulation
the process by which the neural tube is formed
True or False: during the 3rd week, intraembryonic mesoderm proliferates to form a thick column of mesoderm on either side of the notochord
true
what is paraxial mesoderm
right beside the notochord