Cerebral cortex and Diencephalon

Classification of axons

• association

• commissural

• projection fibers

Association axon

connects different parts of brain in same hemisphere

Commissural axon

Run between hemispheres

Projection fiber axons

Connects cortex with different parts of the CNS

2 functions of frontal lobe

1. Controlling voluntary movement

2. Thinking/problem solving

Primary motor cortex location

Precentral gyrus

Primary motor cortex lesion

Paralysis on the contralateral side of the body and muscles of facial expression on the bottom portion of the face

Premotor cortex location

anterior to primary cortex

Premotor cortex function

control action of trunk and limb muscles

Premotor cortex lesion

Unilateral neglect

Primary motor cortex related tracts

• corticospinal

• corticobulbar

Premotor cortex related tracts

• reticulospinal

• vestibulospinal

Supplementary Motor area location

medial to premotor cortex

Supplementary Motor area function

stores motor memories, directs activity of primary motor cortex

Supplementary Motor area lesion

apraxia and motor planning deficit

Brocas area function

Contains motor programs for speech and language

Ataxia

Uncoordinated movement that manifests when movements are attempted, may influence gait, posture, and patterns of movement

Often related to cerebellar lesion

Apraxia

Impairment of a voluntary learned movement that is an inability to perform purposeful movements not accounted for by inadequate strength, impaired sensation, , loss of coordination, attention deficits, or lack of comprehension

Often related to supplemental motor area lesion

Orbitofrontal cortex

contains area for impulse control, inhibition of inappropriate behaviors, and carrying out plans

Orbitofrontal cortex lesion

Patient cant make realistic plans or carry plans out they make. Tend to have trouble with focus, organization, and inhibition of impulses

Prefrontal syndrome

damage in prefrontal cortex heading to changes in personality and behavior

Ventromedial Frontal cortex function

part of limbic system

connects emotions with thought, attaches emotional meaning to life experiences

Ventromedial frontal cortex lesion

flat emotional affect