Lobar Anatomy

Cerebral Hemispheres

The cerebral hemispheres consist of 4 lobes: The frontal lobe, parietal lobe, temporal lobe and occipital lobe. Each lobe is responsible for different functions, but are interconnected. Patients with diseases that affect these regions often present with deficits referable to that specific location. The right and left cerebral hemispheres are connected via a large white matter tract called the corpus callosum which can be seen well on the sagittal MR image (see below). The cerebral cortex (gray matter) is the outer layer of brain tissue and consists of densely packed neurons. The white matter consists primarily of fiber tracts (axons) that connect various parts of the brain and spinal cord. Axons are myelinated, which helps to explain the relative difference in density between the cerebral cortex and white matter.