The document discusses the nervous system and provides details about the central nervous system (CNS), cerebrospinal fluid (CSF), brain, and cerebellum. Key points include: the CNS is covered by three meningeal layers; CSF is produced by choroid plexuses and circulates within the CNS; the brain is divided into lobes and ventricles; and the cerebellum aids in muscle coordination, balance, and sensory integration.

1. NERVOUS SYSTEM

2. CLASS 2
• BRAIN

4. CNS
• BRAIN & SPINAL CORD
• COVERED BY MENINGES
• DURA
• ARACHNOID
• PIA
• SEPERATED BY CSF

7. CNS
• DURA
• DOUBLE LAYERED
• 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 THE BRAIN 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 BY CHOROID 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—720 ml /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—ACTS AS 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 IN THE 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 OF BRAIN
• 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 PART OF 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-GREY MATTER
DEVELOPS FASTER THAN WHITE-RESULTING IN
CONVOLUTIONS
• FOLDS-GYRI
• GROOVES
– FISSURE-DEEP,
– SULCI-SHALLOW
• HEMISPHERE DIVIDED INTO LOBES

26. LOBES
• FRONTAL-CENTRAL SULCUS SEPERATES
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—AXONS IN 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—CONTAIN BOTH 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 SIDE OF 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 GUSTATORY AREA—BASE OF POST
CENTRAL GYRUS IN THE PARIETAL REGION
• PRIMARY VISUAL AREA—LIES BEHIND THE
PARIETO-OCCIPITAL SULCUS
FUNCTIONS OF CEREBRUM

38. • MOTOR AREA—ANTERIOR PART 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—MOTOR SPEECH 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 INPUT IS PROCESSED
• RELAYS IMPULSES BETWEEN AFFERENT AREAS
OF CEREBRUM
• REGULATES AUTONOMIC ACTIVITIES
• MAINTAINS CONSCIOUSNESS
FUNCTIONS OF CEREBRUM

43. • HYPOTHALAMUS --CONTROLS PITUITORY
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 PONS TO 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-
• --IN FRONT 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
– BETWEEN PONS & 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 TO CEREBRUM 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-ORDINATION OF VOLUNTARY MUSCLE
MOVEMENT
– MAINTANANCE OF POSTURE & BALANCE
– SENSORY INPUT FROM PROPRIOCEPTORS(
MUSCLE,JOINTS,EYES,EARS etc)
– LEARNING & LANGUAGE FUNCTION