The basal nuclei (or basal ganglia) are masses of gray matter composed of neuron cell bodies located deep within the white matter of the cerebrum (fig. 8.11). The most prominent of the basal nuclei is the corpus striatum, which consists of several masses of nuclei (a nucleus is a collection of cell bodies in the CNS). The upper mass, called the caudate nucleus, is separated from two lower masses, collectively called the lentiform nucleus. The lentiform nucleus consists of a lateral portion, the putamen, and a medial portion, the globus pallidus. The basal nuclei function in the control of voluntary movements.
Degeneration of the caudate nucleus (as in Huntington's disease) produces chorea—a hyperkinetic disorder characterized by rapid, uncontrolled, jerky movements. Degeneration of dopaminergic neurons to the caudate nucleus from the substantia nigra, a small nucleus in the midbrain, produces most of the symptoms of Parkinson's disease. As discussed in chapter 7, this disease is associated with rigidity, resting tremor, and difficulty in initiating voluntary movements.
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.