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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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Meiosis I vs meiosis II

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Easiest difference between meiosis I and Meiosis II

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Difference between meiosis I and meiosis II Topic Meiosis I Meiosis II Definition Meiosis I is the first phase of meiotic cell division Meiosis II is the second   phase of meiotic cell division Subphases Prophase I, metaphase I, anaphase I & telophase I Prophase II, metaphase II, anaphase II & telophase II Prophase I   of meiosis   Prophase 1 of  Meiosis  is defined by five different phases; Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis There is no subdivisions of prophase II Synapsis Pairing of 46 homologous duplicated chromosomes Absent Crossing over Exchange of large segments of DNA Absent Alignment Alignment of 46 homologous duplicated chromosomes at the metaphase plate Alignment of 23 duplicated chromosomes at the metaphase ...
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Difference between transverse and oblique sinus of pericardium

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Difference between transverse and oblique sinus Transverse sinus Oblique sinus It is an inter-visceral space It is placed between parietal and visceral layer of pericardium It is tubular in shaped Inverted ‘J’ shaped   It is open above It is closed on all sides except below Anteriorly : left atrium and visceral layer of serous pericardium   Anteriorly : ascending aorta and pulmonary trunk     Posteriorly :  parietal layer of pericardium and fibrous pericardium   Posteriorly : intra-pericardial part of superior vena cava and upper margin of left atrium   Above : upper margin of left atrium   Above bifurcation of pulmonary trunk   Inferiorly:  Below upper surface of left atrium   open    Function of transverse sinus: During cardiac surgery, following the  pericardial sac...
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Difference between upper and lower part of anal canal

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Difference between upper and lower part of anal canal Features Upper anal canal Lower anal canal Length 15mm 23mm Extension Anorectal junction to pectinate line Pectinate line to anal orifice Internal features Anal columns Anal valves Anal sinuses Pectinate line White line of Hilton Development From endoderm of the hindgut From ectoderm of proctodeum Innervations Autonomic nerves hence insensitive to pain and temperature Somatic nerves, hence sensitive to pain and temperature Lining epithelium Simple columnar epithelium (upper part of upper part of anal canal ) Stratified columnar epithelium (lower part of upper part of anal canal ) From pectinate line to white line of Hilton non-keratinized Stratified   squamous epithelium   From white line of Hilton to anal orifice : keratinized stratified squamous epithelium Gland ...
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Difference between supra-nuclear and infra-nuclear lesion of facial nerve

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Difference between supra-nuclear and infra-nuclear lesion of facial nerve Supra nuclear lesion of facial nerve Infra nuclear lesion of facial nerve Central palsy Peripheral palsy Forehead intact bilaterally Total facial palsy of one side Tone maintain Flaccid No muscle atrophy Muscle atrophy Reflexes intact No reflexes Ataxia No ataxia Lesion is usually in internal capsule    The facial nucleus itself can be affected by infarcts of the pontine arteries.  Damage of the pyramidal tracts Damage to facial nerve in: - Internal acoustic meatus by a tumour - Middle ear by infection or operation - Facial canal by perineuritis, Bell’s palsy - Parotid gland by a tumour - Lacerations of the face   Lesion is usually at stylomastoid foramen Accompanied by hemiplegia on the same side as facial paralysis Hemiplegia seen only in nuclear paralysi...
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