Chapter 15 Nervous System

Chapter 15  Nervous System

Complete Chapter Questions And Answers
 

Sample Questions

7. ________ Gracile nuclei
a.
Neural crest cells
b.
Alar plates
c.
Basal plates
d.
Neuroepithelium
e.
Spinal ganglion cells

ANS: B
The gracile and cuneate nuclei develop from neuroblasts that migrate from the alar plates into the marginal zone of the myelencephalon. These nuclei are associated with correspondingly named tracts that enter the medulla from the spinal cord.

8. ________ Form ventral gray columns
a.
Neural crest cells
b.
Alar plates
c.
Basal plates
d.
Neuroepithelium
e.
Spinal ganglion cells

ANS: C
The basal plates of the neural tube give rise to the ventral and lateral gray columns of nerve cells in the spinal cord. Axons of the ventral horn cells grow out of the spinal cord and form the ventral roots of spinal nerves.

9. ________ Sympathetic ganglion cells
a.
Neural crest cells
b.
Alar plates
c.
Basal plates
d.
Neuroepithelium
e.
Spinal ganglion cells

ANS: A
Sympathetic ganglion cells are derived from neuroblasts that differentiate from neural crest cells. Some sympathetic neuroblasts migrate to the suprarenal glands where they differentiate into chromaffin cells of the suprarenal medulla.

10. ________ Neuroglia
a.
Neural crest cells
b.
Alar plates
c.
Basal plates
d.
Neuroepithelium
e.
Spinal ganglion cells

ANS: D
Some neuroepithelial cells of the neural tube differentiate into glioblasts (spongioblasts). These cells give rise to oligodendroblasts and astroblasts, which eventually become oligodendrocytes and astrocytes. Oligodendrocytes are concerned with the formation of myelin sheaths within the central nervous system, and astrocytes provide nutrition and general support to the developing neurons. The formation of glial cells continues into adult life.