Cerebrum, Cerebellum & Meninges PDF

CEREBRUM , CEREBELLUM MENINGES DEPARTMENT OF ANATOMY FACULTY OF MEDICINE UKM  Major Brain Cerebrum Subdivisions Thalamus & hypotahalamus Midbrain Pons & cerebellum Medulla oblongata ...

CEREBRUM , CEREBELLUM MENINGES DEPARTMENT OF ANATOMY FACULTY OF MEDICINE UKM  Major Brain Cerebrum Subdivisions Thalamus & hypotahalamus Midbrain Pons & cerebellum Medulla oblongata  Cerebrum Largest part of the brain 2 hemispheres- separated by longitudinal fissure Connected by each other by corpus callosum  CEREBRUM surfaces fissure & sulci lobes functional areas of cerebral cortex & their significances  Gray & White Matter Organization (gray matter) In cerebrum & cerebellum: white matter covered with layer of neural cortex (gray) *Surface area of cerebrum  gray matter SUPERIOR CEREBRUM: LATERA A) SURFACES L INFERIOR MEDIAL CEREBRUM: B) LOBES  CEREBRUM: C) FISSURE & SULCI  MAIN SULCI Central sulcus Parieto-occipital sulcus Lateral sulcus (of Sylvian)  Central sulcus Parieto-occipital sulcus Cingulate Corpus callosum Calcarine sulcus sulcus  CEREBRUM: D) FUNCTIONAL AREAS  IMPORTANT CORTICAL AREAS Frontal lobe NAME LOCATION BRODMANN FUNCTION AREA MOTOR Precentral 4 Voluntary control- gyrus (PCG) opp side of body PREMOTOR Ant to PCG 6 MOTOR Pars triangularis 44,45 Control muscle of SPEECH AREA Pars opercularis speech- expressive of Broca FRONTAL Mid frontal gyrus 6–8- 9 Conjugate m/ment of EYEFIELD eye-no stimuli PREFRONTAL Ant part of frontal 9-10-11-12 Individual AREA lobe personality, initiative, judge MOTOR-for toes Ant part of 4 Voluntary control- and perineum paracentral opp side of body lobule-medial  Primary motor Premotor (2o) area- 6 area-4 Frontal eyefield area-8 Prefrontal area-9,10,11,12 Motor speech area of Broca area-44,45 IMPORTANT CORTICAL AREAS - Parietal lobe NAME LOCATION BRODMANN FUNCTION AREA 1o SENSORY Postcentral gyrus 1,2, 3 sensation-opp side of body 2o SENSORY Inf to Postcentral gyrus SENSORY Superior parietal 5,7 Stereognosis, ASSOC AREA lobule Conscious (general) awareness of opp side SENSORY Inferior parietal 39,40 Interpretation of what ASSOC AREA lobule is seen,heard (special senses) TASTE Lower end of post 43 Taste sensation central gyrus IMPORTANT CORTICAL AREAS Primary Sensory area-1,2,3 Secondary Sensory area Sensory Sensory association association Area (general) Area (special)  IMPORTANT CORTICAL AREAS Temporal lobe NAME LOCATION BRODMANN FUNCTION AREA 1oAUDITORY Lower end of central sulcus & 41 (42) Auditory sensation- AREA sup temporal gyrus both sides 2oAUDITORY Interpretation AREA Close to 1 AUDITORY AREA o WERNICKE Post to 1oAUDITORY AREA For sensory speech OLFACTORY Uncus & anterior part of Sense of smell AREA parahippocampal gyrus  IMPORTANT CORTICAL AREAS Primary auditory Secondary Wernicke area-41,42 auditory sensory area-22 speech LATERAL VIEW area Uncus yrus pa l g hpp ocam Para  IMPORTANT CORTICAL AREAS Occipital lobe NAME LOCATION BRODMANN FUNCTION AREA PRIMARY Walls of 17 Vision VISUAL AREA calcarine sulcus SECONDARY Close to visual 18 Conjugate VISUAL AREA area movement of eye reflex-following stimuli  IMPORTANT CORTICAL AREAS Primary visual area-17 Secondary visual area-18 LATERAL VIEW  IMPORTANT CORTICAL AREAS 4 18,19 Primary visual Secondary cortex-17 visual area-18 MEDIAL VIEW  CEREBELLUM “Little brain” Divides into hemispheres Function – Balance – Posture – Movement Unconsciously control voluntary muscles to produce coordinated and smooth action. Each cerebellar hemisphere controls ipsilateral side of the body  Location Parts Division / Lobes LOCATION within posterior fossa, straddles the brainstem & forms roof of 4th ventricle  Separated from cerebral cortex by PARTS of CEREBELLUM VERMIS HEMISPHERE *2 cerebellar hemisphere joined by vermis  LOBES ANATOMICAL FUNCTIONAL – ANTERIOR LOBE – ARCHICEREBELLUM – POSTERIOR LOBE – PALEOCEREBELLUM – FLOCCULONODULAR – NEOCEREBELLUM ANATOMICAL lobes viewed from superior surface of cerebellum Anterior lobe *Primary Fissure - DEVIDE ANT & POST LOBE Posterior lobe ANATOMICAL lobes viewed from inferior surface of cerebellum Flocculus + Nodule of inferior vermis = Flocculonodular lobe pons mo Posterior lobe mo FUNCTIONAL lobes Neocerebellum Paleocerebellum >>coordination >> posture Archicerebellum = Flocculonodular lobe >>equilibrium  Midline lesion (VERMIS SYNDROME) Paleocerebellum-posture -loss of postural control Neocerebellum-coordination Unilateral (CEREBELLAR HEMISPHERE SYND) – ipsilateral incoordination of limb, may fall to the side of lesion Bilateral – speech (dysarthria), eye movement (nystagmus), bilateral incoordination of limb Archicerebellum-equilibrium Internal structure of cerebellum Gray matter White matter  Cerebellar cortex (outer part), 3 layers – Molecular – Purkinje – Granular inner white matter with embedded deep nuclei  MENINGES Type Structure & function Relate meninges with cerebral haemorrhage WHAT IS MENINGES ?  MENINGES The layers covering the brain Meninges 1. Dura mater - strong, "tough mother" e.g: falx cerebri , falx cerebelli, tentorium cerebelli, diaphragma sella 2. Arachnoid - spidery, holds blood vessels 3. Pia mater - "delicate mother" Dura mater DURA MATER Superior sagittal sinus Inf. sagittal sinus 1) Falx cerebri 2) Tentorium St rai g cerebelli ht sin us 4) Diaphragma sellae 3) Falx cerebelli Sagittal section showing the dura mater  Dura mater DURA MATER  thick dense inelastic membrane  Bilaminar:  Endosteal layer (outer)  Meningeal layer (inner)  Superior sagittal sinus (Dural venous sinus) Dura mater Endosteal layer Not continuous with d.mater of s.cord Meningeal layer continuous with d.mater of s.cord They are CLOSELY UNITED EXCEPT along certain lines; they are separated for passage of venous sinuses Subdural Space - beneath dura mater Coronal section of the upper part of the head  APPLIED ANATOMY (Subdural haemorrhage) : traumatic posterior displacement of brain >> may tear superior cerebral veins SCV (beneath arachnoid mater) >> produces a subdural hematoma >> transverse subdural space >> to reach SSS (within dura mater) Symptoms ; headache, confusion & disturbance of memory  Arachnoid mater ARACHNOID MATER Arachnoid mater - looks like a "spider web“ - resembles a loosely woven fabric which holds arteries and veins. Subarachnoid space - between arachnoid & pia mater - ends at S2 - contains cerebrospinal fluid (CSF) >> to bathe and cushion brain and spinal cord  Arachnoid mater Arachnoid projects into venous sinuses - sites for CSF diffuses into bloodstream Arachnoid granulations Arachnoid villi Arachnoid mater Subarachnoid spac Subdural space e  APPLIED ANATOMY (Subarachnoid haemorrhage) : Rupture of arteries that lie within Subarachnoid space, e.g: aneurysms near the circle of Willis at base of brain >> causes blood to contaminate the CSF Symptoms: Increased intracranial pressure Headache, LOC, Possibly followed by coma & death  Pia mater Pia mater Pia mater - innermost layer - a delicate & highly vascular membrane - providing blood to neural structures, forms dentate ligaments and filum terminale THANK YOU