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Showing posts from December, 2021

Comparison between tract and nerve

  Comparison between tract and nerve Nerve Nerve contain bundle of axons (nerve fibers) in the peripheral nervous system (PNS) that transmits signals between the central nervous system (CNS) and other parts of the body. It is the most important part of peripheral nervous system Location: Peripheral nervous system. Structure: Made of axons, connective tissue layers (endoneurium: axon is surrounded by it , perineurium: bundle of axons are surrounded by it, epineurium: whole nerve trunk is surrounded by it), and blood vessels. It gets myelination by Schwann cell   Function: Carries sensory signals to the CNS (afferent) from peripheral part of body or motor signals carry from from the CNS (efferent) to target organs like skeletal muscle, cardiac muscle, smooth muscle or glands Example: Sciatic nerve, median nerve, except optic nerve (though optic nerve is technically part of CNS in develop...

Difference between granular, agranular, homotypical and heterotypical cortex

  Difference between granular, agranular, homotypical and heterotypical cortex or different cytoarchitectural composition of cerebrum Classification Based on Cytoarchitecture (Cellular Composition) Granular Cortex (Koniocortex) Description : it is well-developed layer IV (internal granular layer), rich in neuron , known as small granular (stellate) cells. Function : it is done sensory processing (receives input from the thalamus). Example : Primary somatosensory cortex (Brodmann areas 3, 1, 2). Primary visual cortex (Brodmann area 17). Primary auditory cortex (Brodmann areas 41, 42). Agranular Cortex Description : it is poorly developed or absent layer IV, contain neuron with large size known as   large pyramidal cells in layer V. Function : it controls motor function   (sends output to spinal cord and brainstem). Example : ...