Structure And Functional Localization Of The Cerebral Cortex Abdelfattah Khdeir M.D

The Highest Level In CNS

Cerebral Cortex Inherited – Learned Responces Gray Matter 10 Billions Neurons – 50 Billions Glial Cells Thickness mm : Thickest VS Thinnest Weight: 600 gm (40 % of total brain weight) Weight: 600 gm (40 % of total brain weight) 180 gm neurons 180 gm neurons 420 gm glial cells 420 gm glial cells

Cerebral Neocortex

Pyramidal Cell

Betz Cells

Stellate Cells

Fusiform Cells

Horizontal Cells of Cajal

Martinotti Cells

Nerve Fibers Of Cerebral Cortex Radial Fibers Tangential Fibers Bands Of Baillarger – Inner / Outer Stria Of Gennari Striate Cortex

Layers Of Cerebral Cortex

I. Molecular Layer I. Molecular Layer II. External Granular Layer II. External Granular Layer III.External Pyramidal Layer III.External Pyramidal Layer Line of Kaes-Bechterew Line of Kaes-Bechterew IV.Internal Granular Layer IV.Internal Granular Layer Outer band of Baillarger - Line of Gennari in area 17 V. Internal Pyramidal Layer V. Internal Pyramidal Layer Giant pyramidal cell of Betz Inner Band of Baillarger VI. Polymorphic Layer VI. Polymorphic Layer

Cortical Column

Association Fibers

CommissuralCommissural Fibers The commissural fibers or transverse fibers connect the two hemispheres of the brain. They include:commissuralhemispheresbrain The transverse fibers of the corpus callosumcorpus callosum The anterior commissureanterior commissure The posterior commissureposterior commissure The lyra or hippocampal commissure.lyrahippocampal commissure Projection Fibers ??

Cortical Areas

Broadman’s Areas

Terms Aphasia : Language Dysfunction Agnosia : Receptive Dysability Apraxia : Motor Dysability

Motor Area

Primary Motor Area Lesion Contralateral Paralysis

Secondary Motor Area Lesion Skilled Movement

Jacksonian Epileptic Seizure

Muscle Spasticity Primary VS Secondary Motor area

Frontal Eye Field Lesion 6,8.,9

PreFrontal Cortex 9,10,11,12

PreFrontal Cortex

Expressive Aphasia

Frontal Lobectomy

Somatosensory Area

Primary Somesthetic Area Lesion Tempreture – Touch - Pressure

Astereognosis

Secondary Somesthetic Area Lesion Ignorance Opposite Side “ SupraMarginal 40 “ Pain

Primary Visual Area

Primary Visual Area Lesion

Secondary Visual Area Lesion Visual Agnosia

Primary Auditory Area Lesion

Secondary Auditory Area Lesion Word Deafness

Receptive Aphasia

Global Aphasia

Dominant Angular Gyrus – 39 Alexia - Agraphia

Silent Area Epilepsy – Amnesia – Auditory Hallucination Deja vu

Insula

Cerebral Dominance Adult VS Pediatric LanguageSpeechWritingCalculation 3D perception Singing Playing Musical instrument instrument

Ventricular System Blood Brain Barier Abdelfattah Khdeir M.D

Subarachnoid Space

Cisterns

Subarachnoid Cisterns Cerebellomedullary cistern (Cisterna magna) - the largest of the subarachnoid cisterns. Cerebellomedullary cistern Pontine cistern (Prepontine cistern or cisterna pontis) Pontine cistern Interpeduncular cistern (Cisterna interpeduncularis) Interpeduncular cistern Superior cistern (Quadrigeminal cistern or cistern of the great cerebral vein) Superior cisterngreat cerebral vein Ambient cistern (Cisterna ambiens) - thin, sheet-like extensions of the superior cistern that extend laterally about the midbrain, connecting it to the interpeduncular cistern. Ambient cistern may also refer to the combination of these extensions and the superior cistern. Ambient cistern

Choroid Plexus

Choroid Plexus Papilloma

Tela Chorioidea

Ependymoma

Lumbar Cistern

CSF

Production Site Production rate Amount Capacity CSF pressure ranges in Pediatrics – Adults Functions ?!

Functions Of CSF Cushions & Protection Against Trauma Mechanical Buoyancy Nourishes CNS Remove Metabolites from CNS As pathway for Pineal Secretions to reach the Pituitary gland

Dural Venous Sinuses

Arachnoid Granulation CSF Pressure VS Venous Pressure

Extension of Subarachnoid Space

PAPILLOEDEMA

Blood Brain Barrier

Blood – CSF Barrier

Intracranial Pressure

ICP Is normally 7–15 mmHg for a supine adult, and becomes negative (averaging − 10 mmHg) in the vertical position.supine Once the ICP has reached around 25 mmHg ?

The Monro-Kellie hypothesis Pressure-volume relationship between ICP, volume of CSF, blood, and brain tissue, and (CPP)

Cerebral Perfusion Pressure CPP = MAP − ICP A vicious cycle

Increased ICP Mass effect Generalized brain swelling Increase in venous pressure Obstruction to CSF flow and/or absorption Increased CSF production

Hydrocephalus

Increased Formation Circulation Blockage Diminshed Absorption Communicating Non-Communicating

Kernicterus