Question

cerebral white matter
most of the remaining cerebral hemisphere tissue—the deeper cerebral white matter (see figures 7 13a and 7.15)—is composed of fiber tracts carrying impulses to, from, or within the cortex. one very large fiber tract, the corpus callosum (kah - losum), connects the cerebral hemispheres (figure 7.15). such fiber tracts are called (1. ). the corpus callosum arches above the structures of the brain stem and allows the cerebral hemispheres to communicate with one another. this is important because, as already noted, some of the cortical functional areas are in only one hemisphere. association fiber tracts connect areas within a hemisphere, and projection fiber tracts connect the (2 ) with lower cns centers, such as the brain stem.
basal nuclei although most of the gray matter is in the cerebral cortex, there are several \islands\ of gray matter, called the basal nuclei, buried deep within the white matter of the cerebral hemispheres (see figure 7.15). the basal nuclei help (3 ) voluntary motor activities by modifying instructions (particularly in relation to starting or stopping movement) sent to the skeletal muscles by the primary motor cortex. a tight band of projection fibers, called the internal capsule, passes between the (4 ) and the basal nuclei.
homeostatic imbalance 7.3 individuals who have problems with their basal nuclei are often unable to walk normally or carry out other (5 ) movements in a normal way. huntingtons disease and parkinsons disease are two examples of such syndromes. (see \a closer look\ pp 252 - 253 )
1 commis sures 2 cerebrum 3 regulate 4 thalamus 5 voluntary
1 cerebrum 2 regulate 3 thalamus 4 voluntary 5 commis sures
1 voluntary 2 commis sures 3 cerebrum 4 regulate 5 thalamus
1 regulate 2 thalamus 3 voluntary 4 commis sures 5 cerebrum
1 thalamus 2 voluntary 3 commis sures 4 cerebrum 5 regulate

Explanation:

1. Fiber tracts that connect the cerebral hemispheres are called commissures. The corpus callosum is a large commissure.
2. Projection fiber tracts connect the cerebrum with lower CNS centers like the brain - stem.
3. The basal nuclei help regulate voluntary motor activities.
4. The internal capsule passes between the thalamus and the basal nuclei.
5. Problems with basal nuclei often affect normal voluntary movements.

Answer:

1. commissures 2. cerebrum 3. regulate 4. thalamus 5. voluntary