The Human BrainThe Human Brain

Central Nervous SystemCentral Nervous System

Brain and Spinal CordBrain and Spinal CordSpinalCord

Brain

Left & Right sides are Left & Right sides are separateseparate

Corpus Callosum : Corpus Callosum : major pathway major pathway between hemispheresbetween hemispheres

Some functions are Some functions are ‘lateralized’‘lateralized’ language on leftlanguage on left math, music on rightmath, music on right

Lateralization is never Lateralization is never 100% 100%

Brain has 2 HemispheresBrain has 2 Hemispheres

LeftHemisphere

Corpus CallosumRight

Hemisphere

Each hemisphere is Each hemisphere is divided into 4 lobes divided into 4 lobes

Frontal

Parietal

Occipital

Temporal

Sensory Information sent to Sensory Information sent to opposite hemisphereopposite hemisphere

Principle is Contralateral Principle is Contralateral Organization Organization

Sensory data crosses Sensory data crosses over in pathways over in pathways leading to the cortexleading to the cortex

Visual CrossoverVisual Crossover left visual field to right left visual field to right

hemispherehemisphere right field to leftright field to left

Other senses similarOther senses similar

Left visualfield

Right visualfield

Opticnerves

CorpusCallosum

Left VisualCortex

Right VisualCortex

Contralateral Motor ControlContralateral Motor ControlMovements Movements

controled by motor controled by motor areaarea

Right hemisphere Right hemisphere controls left side of controls left side of bodybody

Left hemisphere Left hemisphere controls right sidecontrols right side

Motor nerves cross Motor nerves cross sides in spinal cordsides in spinal cord

Somatosensory CortexMotor Cortex

Corpus CallosumCorpus Callosum

Major ( but not only) Major ( but not only) pathway between sidespathway between sides

Connects comparable Connects comparable structures on each sidestructures on each side

Permits data received on Permits data received on one side to be one side to be processed in both processed in both hemisphereshemispheres

Aids motor coordination Aids motor coordination of left and right sideof left and right side

Corpus Callosum

Medial surface of right hemisphere

Lobes of the BrainLobes of the Brain

© 1998-1999 Genentech Inc

Occipital LobeOccipital LobeInput from Optic Input from Optic

nervenerveContains primary Contains primary

visual cortexvisual cortexmost is on surface most is on surface

inside central fissureinside central fissure

Outputs to parietal Outputs to parietal and temporal and temporal lobeslobes

OccipitalLobe

VisualLobe

Temporal LobeTemporal Lobe

Inputs are auditory, Inputs are auditory, visual patternsvisual patterns speech recognitionspeech recognition face recognitionface recognition word recognitionword recognition memory formationmemory formation

Outputs to limbic Outputs to limbic System, basal System, basal Ganglia, and Ganglia, and brainstembrainstem

Contains primary auditory cortex

TemporalLobe

TemporalLobe

AuditoryCortex

ParietalLobe

SomatosensoryCortex

Parietal LobeParietal Lobe

Inputs from multiple Inputs from multiple sensessenses

contains primary somatosensory cortex

borders visual & auditory cortex

Outputs to Frontal lobe

hand-eye coordination

eye movements

attention

FrontalLobe

Frontal LobeFrontal Lobe Contains primary Contains primary

motor cortexmotor cortex MotorCortexMotorCortexBroca’s

Area

MotorCortex

WorkingMemory

No direct sensory inputNo direct sensory input Important planning and Important planning and

sequencing areas sequencing areas Broca’s area for Broca’s area for

speechspeech

Prefrontal area for Prefrontal area for working memoryworking memory

Layers of the CerebrumLayers of the Cerebrum

© 1998-1999 Genentech Inc

Control Centers of the BrainControl Centers of the Brain

© 1998-1999 Genentech Inc