NERVOUS SYSTEMNERVOUS SYSTEM

PARTS OF BRAINPARTS OF BRAIN

HEMISPHERESHEMISPHERES

• Left hemisphere controls right side of the body

• Right hemisphere controls left side of the body

CEREBRAL HEMISPHERESCEREBRAL HEMISPHERES

Left hemisphere Left hemisphere Responsible for speech,Responsible for speech, Math computationsMath computations Processes right visual areaProcesses right visual area

RIGHT HEMISPHERESRIGHT HEMISPHERES

• Spatial tasks, visualizing in 3-D, processes left Spatial tasks, visualizing in 3-D, processes left visual filedvisual filed

• Communicate via Corpus CallosumCommunicate via Corpus Callosum

THE CEREBRAL CORTEXTHE CEREBRAL CORTEX

The outer regionThe outer region

Cerebral cortexCerebral cortex

Formations of folds Formations of folds

ConvolutionsConvolutions

Increase of surface areaIncrease of surface area

THE CEREBRAL CORTEXTHE CEREBRAL CORTEX

Reception of sensory informationReception of sensory informationProcessing the informationProcessing the information

THE CEREBRAL CORTEXTHE CEREBRAL CORTEX

• Stores some memory for future usageStores some memory for future usage• Directs voluntary movementsDirects voluntary movements• Responsible for thinkingResponsible for thinking• The Central CoreThe Central Core

CEREBRAL CORTEXCEREBRAL CORTEX

• Primary sensory area• Reception of signals originating in sense

organs• Conversion of subjective expressions e. g

light and sound• Involve in speech• Interpretation of sensations of touch from

all parts of body

CORTICAL AREASCORTICAL AREAS

• Primary motor area - located in the frontal lobePrimary motor area - located in the frontal lobe• the finer the movement of a body part, the larger the the finer the movement of a body part, the larger the

area it takes up on the primary motor area.area it takes up on the primary motor area.

• Primary sensory areas - the more sensitive a body part Primary sensory areas - the more sensitive a body part is to perception, the larger area it takes up (i.e. the is to perception, the larger area it takes up (i.e. the tongue)tongue)

CORTICAL AREASCORTICAL AREAS

• Visual area - fibers from the right side of both eyes go to the right Visual area - fibers from the right side of both eyes go to the right side of the brain.side of the brain.

• Association areas - all other parts of the brainAssociation areas - all other parts of the brain• receives input from the sensory areasreceives input from the sensory areas• receives input from lower parts of the brainreceives input from lower parts of the brain• involved in perception, thought, decision-makinginvolved in perception, thought, decision-making

CEREBRAL CORTEXCEREBRAL CORTEX

• The Cerebral Cortex - gray matterThe Cerebral Cortex - gray matter • newest portion of the brainnewest portion of the brain• covers the rest of the brain.covers the rest of the brain.• about 1/8 inch thick, contains billions of about 1/8 inch thick, contains billions of

neuronsneurons• 80% of total brain volume80% of total brain volume• can be divided into 4 regions or lobes can be divided into 4 regions or lobes

(occipital, temporal, parietal, frontal(occipital, temporal, parietal, frontal

MID MRAINMID MRAIN• Reduced in humans• Visual reflexesVisual reflexes• Auditory reflexAuditory reflex• Motivation of movementMotivation of movement

• Reticular formationReticular formation• involved in sleep and arousal, excites cerebral cortexinvolved in sleep and arousal, excites cerebral cortex• Relay center connecting hind brain with fore-brainRelay center connecting hind brain with fore-brain• Screening of information before it reach high brain Screening of information before it reach high brain

structurestructure•

MID BRAINMID BRAIN

HIND BRAINHIND BRAIN

• MedullaMedulla

• PonsPons

• CerebellumCerebellum

HIND BRAINHIND BRAIN

PONSPONS

• Appear to influence transitions between sleep and Appear to influence transitions between sleep and wakefulnesswakefulness

• Rate and pattern of breathingRate and pattern of breathing

• Assists cerebellum in controlling movement and postureAssists cerebellum in controlling movement and posture

•

•

MEDULLAMEDULLA

• Hooked directly onto spinal cordHooked directly onto spinal cord• Control several automatic functionsControl several automatic functions• Breathing Breathing • Heart rateHeart rate• Blood pressureBlood pressure• SwallowingSwallowing

CEREBELLUMCEREBELLUM

• Looks like a little brainLooks like a little brain

• In control of force and range of movement.In control of force and range of movement.

• Helps initiate and control rapid limb movement (kicking, punching)Helps initiate and control rapid limb movement (kicking, punching)

• Co-ordinating movements of the bodyCo-ordinating movements of the body

• Guidance Guidance

• Smoothness of motionsSmoothness of motions

• Accuration of motionsAccuration of motions•

CEREBELLUMCEREBELLUM

• Maintenance of body positionsMaintenance of body positions• Learning and memory storageLearning and memory storage• Best developed in birdsBest developed in birds• Engaged in complex activities in flightEngaged in complex activities in flight

•

OTHER AREAS OF BRAINOTHER AREAS OF BRAIN

• Wernicke's area - in left temporal lobe in most people language Wernicke's area - in left temporal lobe in most people language comprehension.comprehension.

• Broca's area - usually on left hemisphere - speach production Broca's area - usually on left hemisphere - speach production problems problems

• Aphasia - disorder of language that is often found when people have Aphasia - disorder of language that is often found when people have

suffered a stroke or some kind of damage to the brainsuffered a stroke or some kind of damage to the brain..

rr

•

SPINAL CORDSPINAL CORD

• Arise from medulla oblongata• Oval shaped hollow cylinder• Composed of large number of neurons,cell

fibers and bodies• Arrangement in a definite pattern• In cross section• Butterfly section

SPINAL CORDSPINAL CORD

Inner portionGrey matterContain a central canalCell bodies and non-myelinated nerve fibers

• Outer portion composed of white matter• Myelinated nerve fibers

SOME NEUROTRANSMITTERSSOME NEUROTRANSMITTERS

• Acetylcholine• Serotonin• Dopamine• Endorphins

SACETYL CHOLINESACETYL CHOLINE

• ACETYL CHOLINE ACETYL CHOLINE • Responsible for muscle communication, Responsible for muscle communication,

affects memory.affects memory.

SEROTONINSEROTONIN

• Affects mood, eating behaviorAffects mood, eating behavior

• Keeps more serotonin in the system.Keeps more serotonin in the system.

DOPAMINEDOPAMINE

• Dopamine - too much = Schizophrenic Dopamine - too much = Schizophrenic symptoms. symptoms.

• Too little = Parkinson symptoms. Too little = Parkinson symptoms. • Drugs treating Schizophrenia can lead to Drugs treating Schizophrenia can lead to

Parkinsonian symptomsParkinsonian symptoms

ENDORPHINSENDORPHINS

Natural opiates Natural opiates • Released in response to pain and vigorous Released in response to pain and vigorous

exerciseexercise•