Exam 3: Nervous System Development II

Question 1

What is located between the midbrain/mesencephalon and hindbrain/metencephalon that produces Wnt-1 anteriorly and FGF-8 posteriorly?

Answer 1

Isthmic organizer

Question 2

What genes are prominent in differentiation?

Answer 2

Hox and Wnt genes

Question 3

What cranial nerve arises from rhombomere 2 and is added to by rhombomere 3 and where do the structures it innervates come from?

Answer 3

Cranial Nerve V.

First pharyngeal arch

Question 4

What cranial nerve arises from rhombomere 4 and is added to by rhombomere 5 and where do the structures it innervates come from?

Answer 4

Cranial nerve VII.

Second pharyngeal arch

Question 5

What cranial nerve arises from rhombomere 6 and is added to by rhombomere 7 and where do the structures it innervates come from?

Answer 5

Cranial nerve IX.

Third pharyngeal arch

Question 6

Motor neurons penetrate _____(anterior/posterior?) mesoderm of somites.

Answer 6

Anterior

Question 7

What organizes and polarizes the dorsal midbrain and cerebellum?

Answer 7

Isthmic organizer

Question 8

What causes dorsoventral patterning of midbrain?

Answer 8

Shh

Question 9

What gene is expressed in the alar plate of the diencephalon and is the “master” gene for eye formation?

Answer 9

Pax-6

Question 10

Shh restricts expression of _____ which is related to the formation of the alar plate.

Answer 10

Pax-7

Question 11

What reciprocal inhibition results in the formation of the diencephalic-mesencephalic border?

Answer 11

Pax-6 & En-1 (& vice-versa)

Question 12

T/F: The secondary rhombencephalon (telencephalon) is under the influence of the notocord.

Answer 12

False, is NOT

Question 13

Which prosomeres define the diencephalon?

Answer 13

P1-P3

Question 14

Which prosomeres define the dorsal and ventral thalamux?

Answer 14

P2-P3

Question 15

The basal plate of the secondary rhombencephalon develops into the _____ and the alar plate develops into the _____, _____, & _____.

Answer 15

Hypothalamus.

Cerebral cortex, Basal nuclei, & Optic vesicles

Question 16

Decreased Shh expression in the ventral forebrain causes tissue formation to be greatly reduced leading to fusion of the optic vesicles. What is the term for this anomaly?

Answer 16

Holoprosencephaly

Question 17

Cell bodies of sensory neurons are derived from _____ cells.

Answer 17

Neural crest

Question 18

What molecules are involved in intracellular adhesion during cell migration or neurite elongation?

Answer 18

N-cadherin, E-cadherin, & L1

Question 19

_____ axons allow peripheral growth toward the target.

Answer 19

Pioneering

Question 20

T/F: GAPs are produced in large amounts during axonal growth.

Answer 20

True

Question 21

What happens to ACh receptors at the location of the postsynaptic fold when the axon meets the muscle fiber?

Answer 21

They concentrate in that area and the others are eliminated

Question 22

Parasympathetic & sympathetic preganglionic motor neurons arise from…?

Answer 22

Intermediate (lateral) horns of gray matter from T1-L2

Question 23

Autonomic ganglia are derived from _____ cells.

Answer 23

Neural crest

Question 24

Postganglionic autonomic neurons are derived from _____ cells.

Answer 24

Neural crest

Question 25

Absence of parasympathetic ganglia from the lower colon and rectum is called?

Answer 25

Hirschsprung’s disease

Question 26

T/F: BMPs determine whether neural crest cells differentiate into autonomic neurons or other neural crest derivatives.

Answer 26

True