How many layers are present in cerebral coex?: (A) 5, (B) 6, (C) 3, (D) 4
Answer is B. Composed of 6 layers. LAYERS OF CEREBRAL COEX: Composed of 6 layers - Layer/Lamina I - "Molecular layer" Contains nerve fibers. Mainly dendrites of pyramidal cells & axons of granular cells. Layer/Lamina II - "External granule cell layer" Contains mainly granule cells. Layer/Lamina III - "External pyramidal cell layer" Contains mainly small to medium size pyramidal cells Some granular cells also present Layer/Lamina IV - "Internal granule cell layer" Contains predominately granule cells & nerve fibers. Specific sensory input through thalamocoical fibers terminate primarily in coical layer IV on stellate (granule cells). Diffuse non-specific sensory afferents are distributed through layer I-IV. Layer/Lamina V - "Internal pyramidal cell layer" Contains large pyramidal cells. Descending tracts, i.e. projection fibers from coex (coicospinal tract, coicobulbar tract) are the axons of these pyramidal cells of Layer V Layer/Lamina VI - "Multiform layer" Contains all types of cells