Embryology: Lecture 11: Establishment of Body Plan II and Extraembryonic Tissues

Question 1

In endoderm formation, what is the anterior-posterior gradient?

Answer 1

Higher levels of nodal anteriorly

Lower levels of nodal posteriorly + the presence of FGF-4 posteriorly

Question 2

What promotes hindgut development and suppresses the formation of anterior gut structures?

Answer 2

Cdx-2 expressed by the posterior gut

Question 3

What are expressed by the anterior gut?

Answer 3

Hex, Sox-2, and Foxa-2

Question 4

Refined differentiation of gut structures depend on___

Answer 4

Hox genes

Question 5

The anterior intestinal portal is influenced by

Answer 5

expression of Shh

Question 6

The posterior intestinal portal is influenced by

Answer 6

expression of Shh followed by BMP-4

Question 7

What is formed by endoderm and ectoderm with no intervening mesoderm?

Answer 7

Oral and cloacal plates

Question 8

What happens when endoderm and ectoderm come together with no mesoderm?

Answer 8

Instability which results in perforations of these plates

Question 9

The stomodeum is the future_____

The proctodeum is the future _____

Answer 9

The stomodeum is the future oral cavity

The proctodeum is the future anal region