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NERVOUS SYSTEM class 2.pptx
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- 4. CNS • BRAIN &SPINAL CORD • COVERED BY MENINGES • DURA • ARACHNOID • PIA • SEPERATED BY CSF
- 7. CNS • DURA • DOUBLELAYERED • OUTER LAYER IS PERIOSTEUM • THERE IS SPACE BETWEEN THE TWO LAYERS AT THE FALX CEREBRUM,CEREBELLUM & TENTORIUM CEREBELLI • BLOOD VESSELS ARE PRESENT BETWEEN THE TWO LAYERS • DURA ENDS AT SECOND SACRAL VERTEBRA - FUSES WITH PERIOSTEUM OF COCCYX
- 8. CNS • EPIDURAL SPACE •SUBDURAL SPACE • SUB ARACHNOID SPACE—CONTAINS CSF • ARACHNOID PASSES OVER THE CONVOLUTIONS • PIA DIPS INO THE CONVOLUTIONS • IT IS CONTINUES AS FILUM TERMINALE& FUSES WITH PERIOSTEUM
- 9. CNS • WITHIN THEBRAIN THERE ARE 4 IRREGULAR SHAPED CAVITIES—VENTRICLES CONTAIN CSF • RIGHT&LEFT –WITHIN THE CEREBRUM COMMUNICATS VIA INTERVENTRICULAR FORAMEN • THIRD –BELOW THE LATERAL VENTRICLE BETWEEN THE THALAMUS CEREBRAL AQUEDUCT • FOURTH –DIAMOND SHAPED CAVITY BETWEEN CEREBELLUM & PONS
- 12. CSF • SECRETED BYCHOROID PLEXUS -- PROLIFERATION OF BLOOD VESSELS SURROUNDED BY EPENDYMAL CELLS • CSF PASSES INTO BLOOD STREAM THROUH ARACHNOID VILLI WHICH OPEN INTO THE VENOUS SINUSES GUARDED BY VALVES • FROM THE ROOF OF THE FOURTH VENTRICLE CSF FLOWS THROUGH FORAMINA INTO THE SUBARACHNOID SPACE & SURROUNDS BRAIN
- 14. CSF • SECRETION 0.5ml/mt—720ml /day • VOLUME OF CSF IS CONSTANT-120ml MAINTAINED BY SECRETION & ABSORPTION • PRESSURE-10cm OF WATER WHILE LYING &30cm WHILE SITTING • CONTAINS—WATER,MINERAL SALTS,GLUCOSE,PROTEIN,ALBUMIN,GLOBULIN ,CREATININE,UREA
- 15. CSF-FUNCTIONS • MECHANICAL PROTECTION—ACTSAS A SHOCK ABSORBER FROM HITTING AGAINST BONE • CHEMICAL PROTECTION-PROVIDES OPTIMAL CHEMICAL ENVIRONMENT ,SLIGHT CHANGE IN IONIC COMPOSITION MAY AFFECT GENERATION & PROPAGATION OF AP • EXCHANGE OF NUTRIENTS & WASTE PRODUCTS—BLOOD CSF BARRIER • MAINTAINS UNIFORM PRESSURE & MOISTURE
- 17. BRAIN • SITUATD INTHE CRANIAL CAVITY • WT 1-1.5 Kg • DEVELOPS FROM ECTODERM ARRANGED AS A TUBULAR STRUCTURE CALLED NEURAL TUBE • THE ANTERIOR PART DEVELOPS IN TO FORE BRAIN—2 CEREBRAL HEMISPHERES,THALAMUS & HYPOTHALAMUS • MID BRAIN—FROM MIDDLE PART • PONS,MEDULLA,CEREBELLUM FROM LOWER PART
- 19. BRAIN • COVERINGS OFBRAIN • THE 2 LAYERS OF DURA ARE FUSED EXCEPT IN PLACES OF BLOOD VESSELS • BLOOD VESSELS THAT ENTER THE BRAIN ARE COVERED BY PIA MATER • 3 EXTENSIONS OF DURA MATER SEPARATE PARTS OF BRAIN • FALX CEREBRI • FALX CEREBELLI • TENTORIUM CEREBELLI
- 22. BRAIN • BLOOD SUPPLY •FROM VERTEBRAL & CAROTID ARTERIES • 15% OF CARDIAC OUTPUT -750 ml • WEIGHT OF BRAIN ONLY 2-3% • USES ONLY GLUCOSE FOR ENERGY • IF NO BLOOD SUPPLY FOR 2 mts NEURONS SUFFER,4mts DEATH • BLOOD SUGAR LEVEL FALLS -FUNCTION IS AFFECTED
- 23. CEREBRUM • LARGEST PARTOF BRAIN • OCCUPIES ANTERIOR & MID CRANIAL FOSSA • 2 HEMISPHERES DIVIDED BY LONGITUDINAL CEREBRAL FISSURE WHICH CONTAINS FALX CEREBRI • CONTAIN 1 VENTRICLE EACH • OUTER GREY,INNER WHITE &GREY MATTER NUCLEI WITHIN THEM • CORPUS CALLOSUM CONNECTS THEM
- 24. CEREBRUM • DURING DEVELOPMENT-GREYMATTER DEVELOPS FASTER THAN WHITE-RESULTING IN CONVOLUTIONS • FOLDS-GYRI • GROOVES – FISSURE-DEEP, – SULCI-SHALLOW • HEMISPHERE DIVIDED INTO LOBES
- 26. LOBES • FRONTAL-CENTRAL SULCUSSEPERATES FRONTAL &PARIETAL LOBES • PARIETAL,PARIETO-OCCIPITAL SULCUS SEPERATES PARIETAL & OCCIPITAL LOBES • TEMPORAL,LATERAL SULCUS SEPERATES FRONTAL FROM TEMPORAL LOBES • GREY MATTER-NERVE CELL BODIES
- 29. CEREBRUM • WHITE MATTER—AXONSIN 3 DIFFERENT TRACTS • ASSOCIATION TRACTS—TRANSMITS IMPULSES WITHIN THE SAME GYRUS • COMMISURAL TRACTS—AXONS THAT CONDUCTS IMPULSES BETWEEN 2 HEMISPHERS -- CORPUSCALLOSUM, ANTERIOR COMMISSURE,POSTERIOR COMMISSURE • PROJECTION TRACTS—AXONS BETWEEN CORTEX AND LOWER PARTS eg INTERNAL CAPSULE
- 30. CEREBRUM • INTERNAL CAPSULE—CONTAINBOTH ASCENDING & DESCENDING TRACTS • MOTOR FIBRES DECCUSATE AT MEDULLA TO FORM PYRAMIDAL TRACTS • DEEP WITHIN CEREBRUM-3 NUCLEI – BASAL GANGLIA – CAUDATE NUCLEUS – CORPUS STRIATUM • THEY ARE CLOSE TO THALAMUS
- 32. CEREBRUM • LIMBIC SYSTEM–EMOTIONAL BRAIN • ENCIRCLING THE UPPER PART OF BRAINSTEM & CORPUS CALLOSUM • BETWEEN CEREBRUM & THIRD VENTRICLE • THALAMUS—2 MASSES OF NERVE CELLS JUST BELOW CORPUS CALLOSUM ON EITHER SIDE OF THIRD VENTRICLE • HYPOTHALAMUS—INFERIOR TO THALAMUS ABOVE PIUITORY GLAND • EPITHALAMUS
- 34. FUNCTIONS OF CEREBRUM •SEAT OF INTELLIGENCE • 3 MAIN FUNCTIONAL AREAS • SENSORY AREA—IMMEDIATELY BEHIND CENTRAL SULCUS • PRIMARY SENSORY AREA HAVE DIRECT COMMUNICATION WITH THE PERIPHERAL SENSORY RECEPTORS • PRIMARY SOMATOSENSORY AREA BEHIND CENTRAL SULCUS-PAIN,TEMPERATURE etc
- 35. • RIGHT SIDEOF BRAIN RECEIVES IMPULSES FROM LEFT SIDE OF BODY • A MAP OF THE ENTIRE BODY IS PRESENT IN THE BRAIN • PRIMARY AUDITORY AREA • SUPERIOR PART OF THE TEMPORAL LOBE IMMEDIATELY BELOW THE LATERAL SULCUS • OLFACTORY AREA –DEEP WITHIN THE TEMPORAL LOBE MEDIAL ASPECT FUNCTIONS OF CEREBRUM
- 36. • PRIMARY GUSTATORYAREA—BASE OF POST CENTRAL GYRUS IN THE PARIETAL REGION • PRIMARY VISUAL AREA—LIES BEHIND THE PARIETO-OCCIPITAL SULCUS FUNCTIONS OF CEREBRUM
- 38. • MOTOR AREA—ANTERIORPART OF HEMISPHERE • PRIMARY MOTOR AREA-PRECENTRAL GYRUS IN THE FRONTAL LOBE—THE CELL BODIES ARE PYRAMID SHAPED(BETZES CELLS).THEY INITIATE THE CONTRACTION OF SKELETAL MUSCLES • EACH REGION CONTROLS SPECIFIC MUSCLES OR GROUP OF MUSCLES • THE FIBRES ARE CROSSED FUNCTIONS OF CEREBRUM
- 39. • BROCAS AREA—MOTORSPEECH AREA • FRONTAL LONBE JUST ABOVE THE LATERAL SULCUS • DOMINANT ON LEFT HEMISPHERE • ASSOCIATION AREAS—SOME MOTOR ,SOME SENSORY FUNCTIONS OF CEREBRUM
- 40. • BASAL GANGLIA--INITIATION & CONTROL OF COMPLEX MOVEMENT,LEARNT & CO- ORDINATED ACTIVITIES • RECEIVE INPUT FROM CORTEX AND PROVIDE OUTPUT TO THE MOTOR AREA • THEY CONTROL UNCONSCIOUS MOVEMENTS LIKE SWINGING OF HANDS WHILE WALKING FUNCTIONS OF CEREBRUM
- 42. • THALAMUS---SENSORY INPUTIS PROCESSED • RELAYS IMPULSES BETWEEN AFFERENT AREAS OF CEREBRUM • REGULATES AUTONOMIC ACTIVITIES • MAINTAINS CONSCIOUSNESS FUNCTIONS OF CEREBRUM
- 43. • HYPOTHALAMUS --CONTROLSPITUITORY GLAND – ANS – BODY TEMPERATURE – EMOTIONS – REGULATES EATING & DRINKING • EPITHALAMUS—HAS PINEAL GLAND – SECRETES MELATONION—INDUCES SLEEP • LIMBIC SYSTEM—EMOTIONAL BRAIN FUNCTIONS OF CEREBRUM
- 46. BRAINSTEM MIDBRAIN EXTENDS FROM PONSTO CEREBRUM AROUND THE CENTRAL AQUEDUCT CONTAINS TRACTS & NUCLEI WHICH CONNECT THE CEREBRUM TO LOWER PART NUCLEI SUPERIOR COLLICULUS—REFLEX CENTRE FOR EYE MOVEMENT INFERIOR COLLICULUS----SKELETAL REFLEX
- 51. BRAINSTEM • PONS- • --INFRONT OF CEREBELLUM ABOVE MEDULLA – 2.5cms LONG – CONTAINS NUCLEI & TRACTS – SOME CONNECT RIGHT & LEFT HEMISPHERES OF CEREBELLUM – HAS PNEUMOTACTIC & APNEUSTIC CENTRE – CONTAIN NUCLEI FOR CRANIAL NERVES – SIGNALS FOR VOLUNTARY MOVEMENTS ORIGINATING IN THE CORTEX ARE TRANSMITTED THROUGH PONS
- 52. BRAINSTEM • MEDULLA – BETWEENPONS & SPINAL CORD – 3cms LONG – CENTRAL FISSURE ON ANTERIOR & POSTERIOR SURFACES – CONTAIN ALL THE SENSORY & MOTOR TRACTS BETWEEN BRAIN & SPINAL CORD – RELAY STATION FOR SENSORY NERVES – VITAL CENTRES ARE PRESENT (CVS,RS,COUGH,SNEEZE,VOMITING,SWALLOWING)
- 53. BRAINSTEM • RETICULAR FORMATION •A COLLECTION OF NEURONS IN THE CORE OF BRAINSTEM • LINKS WITH OTHER PARTS OF THE BRAIN • CO-ORDINATES SKELETAL MUSCLE ACTIVITY • MAINTAINS BALANCE • CO-ORDINATES ANS • RAS-SELECTIVE AWARENESS TO CERTAIN STIMULI
- 55. CEREBELLUM • SECOND TOCEREBRUM IN SIZE • OCCUPIES INFERIOR & POSTERIOR ASPECTS OF CRANIAL CAVITY BEHIND THE PONS • 2 HEMISPHERES SEPERATED BY VERMIS • GREY MATTER IS OUTSIDE • WEIGHT 1/10 OF BRAIN CONTAIN ½ THE NEURONS OF BRAIN • SEPERATED FROM CEREBRUM BY TENTORIUM CEREBELLI • 3 CEREBELLAR PEDUNLES ATTACH THE CEREBELLUM TO BRAINSTEM—SUPERIOR,MIDDLE &INFERIOR CONTAINING AXONS
- 58. CEREBELLUM • FUNCTION – CO-ORDINATIONOF VOLUNTARY MUSCLE MOVEMENT – MAINTANANCE OF POSTURE & BALANCE – SENSORY INPUT FROM PROPRIOCEPTORS( MUSCLE,JOINTS,EYES,EARS etc) – LEARNING & LANGUAGE FUNCTION