Exam 3: Nervous System Development II Flashcards
What is located between the midbrain/mesencephalon and hindbrain/metencephalon that produces Wnt-1 anteriorly and FGF-8 posteriorly?
Isthmic organizer
What genes are prominent in differentiation?
Hox and Wnt genes
What cranial nerve arises from rhombomere 2 and is added to by rhombomere 3 and where do the structures it innervates come from?
Cranial Nerve V.
First pharyngeal arch
What cranial nerve arises from rhombomere 4 and is added to by rhombomere 5 and where do the structures it innervates come from?
Cranial nerve VII.
Second pharyngeal arch
What cranial nerve arises from rhombomere 6 and is added to by rhombomere 7 and where do the structures it innervates come from?
Cranial nerve IX.
Third pharyngeal arch
Motor neurons penetrate _____(anterior/posterior?) mesoderm of somites.
Anterior
What organizes and polarizes the dorsal midbrain and cerebellum?
Isthmic organizer
What causes dorsoventral patterning of midbrain?
Shh
What gene is expressed in the alar plate of the diencephalon and is the “master” gene for eye formation?
Pax-6
Shh restricts expression of _____ which is related to the formation of the alar plate.
Pax-7
What reciprocal inhibition results in the formation of the diencephalic-mesencephalic border?
Pax-6 & En-1 (& vice-versa)
T/F: The secondary rhombencephalon (telencephalon) is under the influence of the notocord.
False, is NOT
Which prosomeres define the diencephalon?
P1-P3
Which prosomeres define the dorsal and ventral thalamux?
P2-P3
The basal plate of the secondary rhombencephalon develops into the _____ and the alar plate develops into the _____, _____, & _____.
Hypothalamus.
Cerebral cortex, Basal nuclei, & Optic vesicles
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?
Holoprosencephaly
Cell bodies of sensory neurons are derived from _____ cells.
Neural crest
What molecules are involved in intracellular adhesion during cell migration or neurite elongation?
N-cadherin, E-cadherin, & L1
_____ axons allow peripheral growth toward the target.
Pioneering
T/F: GAPs are produced in large amounts during axonal growth.
True
What happens to ACh receptors at the location of the postsynaptic fold when the axon meets the muscle fiber?
They concentrate in that area and the others are eliminated
Parasympathetic & sympathetic preganglionic motor neurons arise from…?
Intermediate (lateral) horns of gray matter from T1-L2
Autonomic ganglia are derived from _____ cells.
Neural crest
Postganglionic autonomic neurons are derived from _____ cells.
Neural crest
Absence of parasympathetic ganglia from the lower colon and rectum is called?
Hirschsprung’s disease
T/F: BMPs determine whether neural crest cells differentiate into autonomic neurons or other neural crest derivatives.
True
