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Showing posts from March, 2019

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...

Histological features of osteoblast

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Histological features of osteoblast Size   : 15-30 µm •       Cuboidal, low columnar or polygonal , •       arranged in single layer, •       eccentrically placed oval single nuclei •       cytoplasm is basophilic leaving a clear area due to golgi complex, •       Ultra structurally they have features typical of protein secreting cells •       Cytoplasm contain abundant rER and free ribosomes •       Cell membrane of osteoblast has processes which communicate with the adjucent osteoblasts and with osteocytes by gap junctions

Difference between mediastinal surfaces of right and left lung

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Difference between mediastinal surfaces of right and left lung  Mediastinal part of lung: the impression and relation of mediastinal surface differ in two lungs Mediastinal surface of right lung: Cardiac area is related with    Anterior surface of Right auricle, Anterior and right surface of right atrium,   Part of anterior surface of right ventricle   In front of hilum upper part : Groove for SVC In front of hilum lower part groove for   IVC are present Above the hilum : groove for azygous vein Behind the hilum : osophagus except upper and   lower part From apex to groove for azygous vein:Anterioposteirly Right brachiocephalic vein,Trachea,Osophagus Three neural structures:right phrenic nerve, Right vagus nerve, Right sympathetic chain Mediastinal surface of left lung Cardiac area is related withAnterior and left surface of left ventricle and left auricle, Anterior surface of a part of the right ventricle...