Cerebral Cortex - Bellarmine University

Cerebral Cortex Medical Neuroscience Dr. Wiegand Comparative Anatomy human cat rat Humancortical cortical expansion expansionnot

not strictly strictlydue due Human toenlarged enlarged motor motor or or primary primarysensory sensoryareas areas to Longitudinalfissure fissure

Longitudinal Gyri& & Gyri sulci sulci Lateral Lateralor or Sylvian Sylvian fissure fissure

Landmarks Precentral & postcentral gyri Lateral Lateralor or Sylvian Sylvian fissure fissure Centralsulcus sulcus

Central ParietoParietooccipital occipital sulcus sulcus Preoccipital Preoccipitalnotch notch Lobes poles Frontal lobe

Parietal lobe operculum Temporal lobe Occipital lobe Medial Surface Centralsulcus sulcus Central Frontal lobe

Parietal lobe ParietoParietooccipital occipital sulcus sulcus Occipital lobe Frontal lobe Sup./mid./inf. gyri Precentral gyrus/sulcus

Pars orpercularis, triangularis, orbitalis Parietal Lobe Post central gyrus Supramarginal and angular gyri Superior parietal lobule Temporal Lobe Sup./mid./inf. gyri Transverse gyri

Corpus callosum Callosal sulcus Cingulate gyrus/sulcus Anterior commissure Superior frontal gyrus Paracentral lobule Precuneus Cuneus Calcarine sulcus Lingual gyrus Fornix Septum pellucidum

Gyrus rectus Olfactory sulcus/tract/bulb Olfactory stria Orbital gyri Occipitotemporal gyrus Parahippocampal gyrus & uncus Collateral & rhinal sulci Ant./post. perforated substance Deep Telencephalic Nuclei

claustrum Gray Matter of the Cerebral Cortex Archicortex 3 layers (hippocampus) Neocortex 6 cellular layers Hippocampal formation = hippocampus + dentate gyrus

Neocortex Neocortex 6 cellular layers I. II. III. IV. V. VI.

Molecular layer mostly neuropil External granular layer stellate cells External pyramidal layer small pyramidal cells Internal granular layer stellate cells Internal pyramidal layer large pyramidal cells Multiform layer multiple cell types

I II III IV V VI sensory association motor

Association & Commissural Thalamocortical afferents Corticofugal efferents Corticothalmic efferents Brodmann Areas Area 4 = primary motor cortex Areas 3, 1,2 = primary somatosensory cortex Area 17 = primary visual cortex

Areas 41, 42 = primary auditory cortex White Matter intracortical intercortical projection fibers Commissural Fibers Anterior Commissure

Posterior Commissure Preoptic nuclei (vision) Habenular Commissure

Inf. & mid. temporal gyri, olfactory areas Habenular nuclei (olfaction) Corpus Callosum Connects hemispheres Rostrum, genu, body & splenium Commissural Fibers

Anterior Commissure Posterior Commissure Preoptic nuclei (vision) Habenular Commissure

Inf. & mid. temporal gyri, olfactory areas Habenular nuclei (olfaction) Corpus Callosum Connects hemispheres

Rostrum, genu, body & splenium Association Fibers Short fibers connect adjacent gyri Long fibers Superior longitudinal fasc. Arcuate fasciculus

Inferior longitudinal fasc. Cingulum septal area, cingulate and parahippocampal gyri Uncinate fasc. orbital frontal gyri to temporal pole Projection Fibers Internal Capsule Organization medial lateral

Cortical Functional Organization Precentral gyrus Similar organization in visual, auditory and somatosensory cortices