Embryology III

Question 1

What molecules are in charge of ventral patterning? OF dorsal patterning in spinal cord?

Answer 1

ventral: sonic hedgehog
dorsal: bone morphogenic proteins

Question 2

What genes controls rostrocaudal patterning?

Answer 2

homeobox genes and hox genes

Question 3

What makes up the pyramids on the ventral surface of the medulla?

Answer 3

prominent bundle of axons on the ventral surface of the medulla

Question 4

Generally, what is found in the pontine tegmentum?

Answer 4

cranial nerve nuclei from alar and basal plates and the reticular formation

Question 5

From what does the cerebellum develop?

Answer 5

rhombic lips of the pontine alar plates.

Question 6

What happens during the first trimester of cerebellar development?

Answer 6

cerebellar plate begins with ventricular, intermediate and marginal zones. 2nd layer of neuroblasts arrive to form the external germinal layer (marginal zone) and the internal germinal layer (intermediate zone). Cells migrate along the radial glia.

Question 7

What is derived from the internal germinal layer of the cerebellum?

Answer 7

deep cerebellar nuclei and the purkinje cells

Question 8

What is derived from the external germinal layer of the cerebellum?

Answer 8

granule cells

Question 9

What are the alar plate derivatives of the midbrain?

Answer 9

superior and inferior colliculi, red nucleus, substantia nigra

Question 10

What are the basal plate derivatives of the midbrain?

Answer 10

oculomotor, trochlear, and edinger westphal nuclei

Question 11

What forms the crus cerebri?

Answer 11

invasion of the midbrain marginal layer by axons originating in cells outside the midbrain

Question 12

What is the massa intermedia?

Answer 12

fused thalamus across the space of the third ventricle

Question 13

What is a key difference between the development of the thalmus and the development of the cortex? Think about glia!

Answer 13

in the thalamus, the first cells to migrate are located mos laterally (they go all the way, and later ones fill in the gap). in the cerebral cortex, the first cells to migrate are located closest to the ventricular surface, and later cells take up positions closer to the pia surface.

Question 14

What is a guide that helps with the devo of commissural axons?

Answer 14

lamina terminalis

Question 15

when does the corpus collosum appear?

Answer 15

10 wks development

Question 16

What does the stria terminalis connect?

Answer 16

hypothalamus and amygdala