cerebral cortex

Cortex =

“Bark”

Cerebral cortex is made up of-

Temporal lobe, occipital lobe, parietal lobe

3 parts of inferior frontal gyrus

Pars opercularis

Pars triangularis

Pars orbitalis

Paracentral lobule

Medial surface. Has motor and sensory function of the legs

Neocortex (most of cerebral cortex)

Six layers

95% of surface hemisphere

Paleocortex

3 layers (parahippocampal gyrus, cingulate gyrus)

Archicortex

Four layers

Hippocampus

Motor cells have the most-

Long axons

More pyramidal cells=

Less granular cells=agranular

More granular cells=

Less pyramidal cells= granular

Nonpyramidal cells-

Serve as principal interneurons of the neocortex (relay local information)

Cortical layers

1. Axons and dendrites

2.Corticospinal/ 3. corticocortical

4. Thalamic afferents

5. Subcortical efferent

6. Thalamic efferents

Column is-

Primary computational unit of cortex

Arcuate fasciculus (white matter bundles)

Association bundles

Internal capsule (white matter bundles)

Projection bundles

corpus callosum and anterior commissure

Commisural bundles

Primary motor cortex (m1)

Region most associated with outside world

Homunculus

Unimodal association (sensory and motor)

Elaborate on the info from primary cortex

Hetermodal association (higher-order cognition)

Participate in various stimulus response if processing needed

Supplementary motor area

Encodes sequences of movements

Premotor cortex

Neurons fire just before performing an activity

Damage to primary motor cortex-

Produces dysfunction of contralateral distal muscles

Jacksonian seizure:

A patient having seizures that starts as twitching and spread to other parts in the same side of the body

Damage to precentral gyrus (facial muscles)

Paralysis in voluntary movements

Damage to limbic cortex (facial muscles)

Results in inability to express true emotions