- An 18-month-old girl flexes the great toe toward the top of her foot
and the other toes fan out after the sole of her foot has been firmly stroked
by the pediatrician. A year later, the response cannot be evoked by the
same stimulus. The change in response is due to which postnatal event?
a. Apoptosis of exuberant neurons in the cortex by microglia
b. Maturation of the cerebellar cortex
c. Myelination of the lumbar spinal nerves by Schwann cells
d. Myelination of the corticospinal tract by oligodendrocytes
e. Formation of new neurons in the cerebral cortex
- A 2-year-old boy has an acute inflammatory reaction in the region
shown in this photomicrograph several weeks after suffering from chicken-
pox. Which of the following is the most likely symptom?
230 Anatomy, Histology, and Cell Biology
a. Amnesia
b. Ataxia
c. Loss of spinal cord reflex responses
d. Loss of pain sensation
e. Aphasia