Chapter 2. Prehension

Chapter 4 - Planning of Prehension
Motor cortex Primary somatic
Figure 4.4 Levels of the CNS include the cerebral hemispheres,
brain stem and spinal cord. Sensory and motor systems innervat-
ing the trunk and limbs must cooperate and integrate information
in order to carry out a behavioral act such as grasping an object.
Afferent information acts at spinal levels or ascends, synapsing in
the dorsal column nuclei and thalamus before reaching the so-
matosensory and motor regions of the cerebral cortex. The direct
motor pathway descends from the motor cortex to excite
motoneurons in the spinal cord, monosynaptically or through
interneurons. The excitability of these motor neurons is also a
function of spinal and descending influences from rubrospinal,
reticulospinal, tectospinal and vestibulospinal pathways (from
Kandel and Schwartz, 1985; reprinted by permission).
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