Cerebellum, cerebral lobes and white matter tracts Notes

The Cerebellum: The Automatic processing center that monitors proprioceptive, visual, tactile, balance, and auditory sensations

Two primary Functions:

---Adjusting the postural muscles of the body

---Programming and fine-tuning movements controlled at the conscious and subconscious levels

It has large anterior and posterior lobes, covered by a thin layer of gray matter called the cerebellar cortex.

Purkinje cells are highly branched and create an outer molecular layer on the cerebellar cortex

Ataxia is a disturbance in muscular coordination resulting from damage to the cerebellum

Lobes of the Cerebral Hemispheres

Precentral Gyrus--contains primary motor neurons

Central sulcus--divides frontal and parietal lobes

postcentral gyrus--contains primary sensory cortex

Parieto-occipital gyrus--separates the parietal lobe from the occipital lobe

Frontal lobe

Temporal Lobe

Occipital Lobe

Parietal Lobe

White Matter of the Cerebral Hemispheres

association fibers--interconnect areas of neural cortex within a single cerebral hemisphere

--arcuate fibers--shortest association fibers

--longitudinal fasciculi--connect frontal lobe to other lobes of the same cerebral hemisphere

commisural fibers--connect cerebral heispheres

--projection fibers--link cerebral cortex to the diencephalon, brain stem, cerebellum, spinal cord

--internal capsule--mass of all projection fibers passing through diencephalon

--corpus callosum--allows communication between left and right cerebral hemispheres

--anterior commissure--backup commissure, esp. important if the corpus callosum suffers damage

Electroencephalogram--printed report of electrical activity of the brain

alpha waves--occur when resting with eyes closed...disappear during sleep, or concentration

beta waves--higher frequency waves, appear with concentration or psychological tension

theta waves--appear transiently during sleep, or intense frustration. May signify brain disorder

delta waves--deep sleep, damaged portions of brain during waking.

Chapter 13