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Comparison between tract and nerve

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  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...
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Difference between inductor and evacator

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Difference between inductor and evacator Inductor : An inductor is a tissue or group of cells present in embryonic life that sends signals to direct the development of another embryonic tissue. It initiates or controls differentiation of specific embryonic tissue by releasing specific molecules (e.g., growth factors). Example: N otochord acts as an inductor for the formation of the neural tube in early embryonic development. If notochord fail to form , there is no formation of neural tube Evocator An evocator is the chemical signal or molecular factor that carries out the induction process which occurred within embryonic tissue . It is usually a protein, morphogen, or growth factor that triggers changes in the target embryonic cells. Example: Bone Morphogenetic Proteins (BMPs), Sonic Hedgehog (Shh), and Fibroblast Growth Factors (FGFs) act as evocators in various developmental pr...
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Difference between eccrine and apocrine sweat gland

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Difference between eccrine and apocrine sweat gland Topics eccrine sweat gland apocrine sweat gland Distribution Entire body surface except for the lips and part of the external genitalia Axilla , areola , nipple of mammary gland , skin around the anus and the external genitalia Lumen of secretory portion Narrow Wider Overall diameter of secretory coil 500-700 µm 800 µm Diameter of individual secretory tubule 30-40 µm 80-100 µm Composition of secretory unit single layer, contain three type of cells : clear cells , dark cells and myoepithelial cells single layer columnar cells contain single cell type with myoepithelial cells Duct opens to skin surface hair follicle, sometimes nearby skin surface Overall diameter of secretory coil 500-700 µm 800 µm Function Tempera...
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Difference between pyramidal system and extra-pyramidal system

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Difference between pyramidal system and extra-pyramidal system  Topics Pyramidal system Extrapyramidal system Phylogeny Present in mammal and achieving its greatest development in man Phylogentically it is older than pyramidal system Brodman’s area Brodman’s area 4 Brodman’s area 6 Component Pyramidal cells in the primary motor area 4, premotor area 6 , primary sensory are 3,1,2 Premotor area   corpus striatum , globus pallidus, tectum, red nucleus , reticular formation , vestibular nuclei and neocerebellum Crossing of nerve fibres 80% cross in medulla and 20% cross in spinal cord Most of the extrapyramidal tract cross except vestibulospinal Function Responsible for non-postural, precise movements of small muscles involved in skillful activity Responsible for gross postural movemen...
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