Brain

Brain Protective coverings Cranium Cranial meninges: 1- Dura mater 2- Arachnoid mater 3- Pia mater

Major parts of the brain Cerebrum Brain stem Cerebellum diencephalon

The cerebrum Cerebrum is the largest part of brain. Situated in anterior and middle cranial fossa.

Third ventricle Slitlike cleft between the two thalami. Communicates anteriorly with lateral ventricles, and posteriorly with fourth ventricle.

Lateral ventricles There are two lateral ventricles; one in each hemisphere. Each one is roughly C-shaped cavity. Divided into body, anterior, posterior and inferior horns.

Fourth ventricle has a characteristic diamond shape in cross-sections It is located within the pons or in the upper part of the medulla

Consists of three types of tracts: Cerebral white matter Consists of three types of tracts: Association tracts Commissural tracts (Corpus callosum) Projection tracts (internal capsule)

Association fibers

Cortical areas Frontal lobe Primary motor area (area 4). Secondary motor area(area 6) Frontal eye field area Prefrotal cortex Motor speech area of Broca (Brodmann’s areas 44, 45)

Pariteal lobe: Primary somatic sensory cortex (Brodmann’s areas 3,1 and 2). Somesthetic association area (5,7).

Occipital lobe: Primary visual area (Brodmann’s area 17). Secondary visual area (Brodmann’s areas 18,19).

Temporal lobe: Primary auditory area (Brodmann’s areas 41,42). Secondary auditory area (Brodmann’s area 22). Sensory speech area of Wernicke.