Physiology of cerebral cortex

•The cerebral cortex is made of 3 types of cells:
1.Granular Cells: which are intercortical neuron and they have short axons. They are either excitatory and contain glutamate as a neurotransmitter or inhibitory and contain GABA as a neurotransmitter.
2.Pyramidal Cells: They have long axons and they make connections to the spinal cord and thalamus.
3.Fusiform Cells: They have long axons.
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•The cerebral cortex is made also of 6 layers:
1.Layers 1,2,3 are for intercortical association functions.
2.Layer 4 is a relay for the incoming signals.
3.Layers 5 & 6 are for the output.
Primary Areas:
Motor: For discrete muscle movement.
Sensory: To detect specific sensations such as primary visual, primary auditory and primary somatic.
Secondary Areas: Make senses out of the functions of the primary areas such as the secondary auditory, secondary visual, secondary somatic and supplemental and premotor area.
Association Areas: These also receive and analyze signals from motor and sensory cortex and subcortical structures. These are the following:

-This area gives the meaning of the signals from all the surrounding sensory areas which are the visual, auditory and somatosensory.
-It also analyzes the spatial coordination of the body such as the visual information and the somatic information from the anterior parietal cortex.
The Wernicke’s Area (area for language comprehension): lies at the posterosuperior portion of temporal lobe, It is the most important area for higher intellectual functions, It is well developed in the dominant hemisphere.
Damage to this area give rise to Wernicke Aphasia in which there is impaired comprehension and interpretation and formulation of thought (the patient understand spoken language or written words i.e. hear and recognize different words and read words from printed pages , but unable to interpret the thought that is expressed(dementia).
Stimulation of this area causes complicated memories such as complicated visual senses and auditory hallucinations as musical pieces or persons sound.
The area for processing of visual language (Reading) is also situated in the (P.O.T) and it lies in the Angular Gyrus, behind the Wernicke’s Area. This area makes meaning out of the visually perceived words by transmitting it to the Wernicke’s area.
Damage to this area or Angular Gyrus leads to Word Blindness or Dyslexia.( the patient is able to see words but not able to interpret their meaning).
The area for naming objects lies in the P.O.T also, deep in the Temporal lobe.