Question

1-Describe the process of myelination. What is it, and what causes it to occur?

2-What is the result of myelination, that is, how does it affect neural communication?

3-The brain can also be divided into two hemispheres, the right hemisphere and the left hemisphere.     List the primary cognitive functions of each hemisphere.

4-Describe a) the corpus callosum, b) it’s primary function, and c) when it develops in relation to the brain hemispheres and cortex?

5- What affect does watching TV or playing video games have on the development and ability of the corpus callosum?

Answer 1

1. Myelination starts in the peripheral nervous system where the motor roots come to be myelinated earlier than sensory roots (that happens from the second to the fifth month). Myelination then starts in the spinal cord at around 11 weeks and continues according to a craniocaudal gradient. In the third trimester, myelination begins in the brain, but compared to the peripheral nervous system, myelination is seen first in the sensory tracts (e.g., in the visual system). In the corticospinal tracts, the most important direct connection among the cerebral cortex and the motor nerves originating from the spinal cord, myelination ranges caudally to the level of the medulla only by 40 weeks.