12. The Central Nervous System

Infants have little to no control of the movements of their head. One of the consequences of this is that they are susceptible to shaken baby syndrome, caused by vigorous shaking of an infant or young child by the arms, legs, chest, or shoulders. Forceful shaking can cause brain damage leading to mental retardation, speech and learning disabilities, paralysis, seizures, hearing loss, and even death. Damage to which areas of the brain would account for the clinical signs observed in this syndrome?

Describe the spinal cord, depicting its extent, its composition of gray and white matter, and its spinal roots.

Proceeding deep from the most superficial structure, number the following in the correct sequence:

(a) _____ walls of vertebral canal

(b) _____ dura mater

(c) _____ subdural space

(d) _____ epidural space

(e) _____ pia mater

(f) _____ arachnoid membrane

(g) _____ subarachnoid space

(h) _____ spinal cord

Describe the functional problems that would be experienced by a person in which these fiber tracts have been cut:

a. Lateral spinothalamic

b. Ventral and dorsal spinocerebellar

c. Tectospinal

The synapsing of several neurons on the same postsynaptic neuron is called

(a) Serial processing

(b) Reverberation

(c) Divergence

(d) Convergence

Identify and shade in the locations of all the ascending sensory tracts in the following diagram of the spinal cord.

Which three pairs of descending tracts make up the corticospinal pathway?

Which three motor tracts make up the medial pathway?

The corticospinal tract

(a) Carries motor commands from the cerebral cortex to the spinal cord

(b) Carries sensory information from the spinal cord to the brain

(c) Starts in the spinal cord and ends in the brain

(d) Does all of these

Describe the relationship among first-order, second-order, and third-order neurons in a sensory pathway.