Somites and embryonic folding

Question 1

Where do the clefts appear

Answer 1

intraembryonic mesoderm

Question 2

What shape do the clefts eventually form when fully joined together

Answer 2

Open ended horseshoe

Question 3

What is the horseshoe cavity called

Answer 3

intraembryonic coelom

Question 4

What three cavities are formed from the intraembryonic coelom

Answer 4

pericardial, pleural, peritoneal

Question 5

What three columns are formed from intraembryonic mesoderm

Answer 5

paraxial, intermediate, lateral plate (continuous with extraembryonic mesoderm)

Question 6

What does the paraxial mesoderm form in the fourth week

Answer 6

Paired cuboidal bodies called somites

Question 7

What does the intermediate mesoderm become

Answer 7

nephrotome (genitourinary system)

Question 8

What does the lateral mesoderm become

Answer 8

either parietal (body wall) or visceral (wall of gut)

Question 9

What does the lateral plate split into

Answer 9

Somatopleuric mesoderm (amniotic cavity, forms striated muscle) and splanchnopleuric mesoderm (yolk sac, smooth muscle of gut)