What's the difference between fascicle and perineurium?
Fascicle
Definition:
(n.) A small bundle or collection; a compact cluster; as, a fascicle of fibers; a fascicle of flowers or roots.
Example Sentences:
(1) In some areas, the tumor shows a striking resemblance to Kaposi's sarcoma; criss-crossing fascicles of spindle cells are interspersed with narrow vascular spaces, but PAS-positive hyaline globules are absent.
(2) Pain induced by INMS in muscle nerve fascicles was projected to the muscles innervated by that fascicle and, in most instances, to areas beyond the muscular receptive field.
(3) with 2-6 times increased stimulation strength produced skin vasodilatation restricted to the innervation zone of the stimulated nerve fascicle.
(4) Total myelinated fiber density was high in the small fascicles, and it decreased as the fascicles became larger in size, approaching the values observed in the large peripheral nerves.
(5) Theories for the decreased antigenic reaction of nerve fascicles are proposed.
(6) the solitary complex and the superficial rostral cuneate fascicle, were found to contain neuronal perikarya displaying a normally weak staining which was markedly enhanced after monoaminoxidase (MAO) inhibition.
(7) The superior fascicle is whitish, dimmed and frequently thinner than the others and was classified under 4 patterns, according to its insertion.
(8) Without endocardial mapping many of these tachycardias would have been incorrectly identified as originating in the fascicles or epicardium.
(9) Individual fibers of all classes appeared to innervate fascicles of smooth muscle in the mesometrium of the uterine horn.
(10) Most examples measure less than or equal to 0.5 cm and are composed of a partially encapsulated mass of bland Schwann cells and innumerable tiny axons arranged in interlacing fascicles.
(11) Second, the percentages of subjects with 1 or more fascicles exceeding the proposed threshold were as follows: 45.8% for the four-component, 28.8% for the three-component, and 32.7% for the two-component contracture test.
(12) They aggregate to form fascicles that lie among somatic axons, being separated from them.
(13) The ipsilateral fascicles projected to almost all the above mentioned nuclei, but these projections were comparatively sparse.
(14) Biopsied fascicles of cutaneous nerves from clinically affected (forearm) and from clinically unaffected (leg) regions permitted a comparison of well-advanced and early pathologic lesions, respectively.
(15) Most often, however, brain stem lesions also involve structures surrounding the ocular motor nuclei or fascicles, sometimes leading to characteristic eponymic syndromes.
(16) Microelectrodes were inserted percutaneously into a fascicle of the peroneal nerve to measure sympathetic discharge to muscle.
(17) Ethylenethiourea (ETU), at greater than or equal to .5 mM concentrations, caused in monocell layers in vitro a necrosis of neuronal cells and a marked depression in the formation of neurites and fascicles without any noticeable change in the non-neuronal cells.
(18) At highest risk were 186 patients with blocks involving the right bundle and at least one fascicle of the left bundle which were not documented on prior electrocardiograms.
(19) Grafts with myotubes at right angles to the nerve fascicles supported nerve regeneration but at a slower rate.
(20) Microneurographic techniques were used to isolate single afferent axons within cutaneous and motor fascicles of the median and ulnar nerves at the wrist in thirteen subjects.
Perineurium
Definition:
(n.) The connective tissue sheath which surrounds a bundle of nerve fibers. See Epineurium, and Neurilemma.
Example Sentences:
(1) Electron microscopic observations of the masseter nerve in the aged cats revealed a disruption of the myelin sheaths and a pronounced increase in collagen fibers in the endoneurium and perineurium.
(2) At four weeks, a perineurium-like sheath surrounded the regenerate and longitudinally oriented Schwann cell columns could be observed throughout the regenerate.
(3) If the alterations involve the inner layers of the perineurium, they are likely to impair its barrier function.
(4) The permeability properties of the perineurium in sciatic nerves of 12-week-old rats were studied.
(5) Transperineurial arterioles are defined as any arteriole that is confined to a perineurial cell compartment, which would include all arterioles within the perineurium proper or within perineurial sleeves in the epi- or endoneurium.
(6) This finding is significant in relation to the putative role of the perineurium as a metabolically active perifascicular diffusion barrier that regulates the composition of the endoneurial fluid, as is its possible relevance to the occurrence of endoneurial edema in diabetes.
(7) Perineurial infiltration by lymphocytes and bacillated macrophages was seen to occur through gaps between the constituent cells of a loosened and sometimes proliferated perineurium.
(8) Symptoms occur because adjacent nerve roots are impinged upon by the thin-walled, fluid-filled cysts, which are formed in a space between the endoneurium and the perineurium.
(9) Aminopeptidase N was also observed in connective tissue elements, including the perineurium.
(10) Luminal narrowing and mural thickening of these vessels was compounded by basal laminar thickening of the perineurium.
(11) The perineurium surrounding the olfactory filaments at the superficial submucosal level is only one cell thick.
(12) The calcium phosphate deposits were limited to the outer layers of the perineurium while the innermost lamellae were free.
(13) Peripheral nerves in this animal, as in vertebrates, are covered by endoneurium, perineurium, and epineurium.
(14) The results suggest that the crayfish perineurium is a leaky epithelium capable of a high degree of ion regulation.
(15) The glial cells most affected are those which make up the perineurium.
(16) Type IV cells have long processes which usually become incorporated in bundles containing 2--20 processes, including some cholinergic nerve fibres, and are loosely enveloped by perineurium.
(17) The wall is composed of perineurium and neural tissue.
(18) Large numbers of intact organisms can be seen within the perineurium using electron microscopy, and after extensive sampling a few organisms can be detected within the axon cytoplasm.
(19) It is concluded that M. leprae which are extruded from the circulation into the epineurium (or perineurium) may be carried in inflammatory cells across the perineurium which is loosened and rendered permeable to inflammatory cells as a consequence of chronic inflammation in the adjacent epineurium.
(20) A critical evaluation of the various methods of nerve suture, followed by the description of a new personal method of "mixed suture" taking up the neurolemma and the perineurium in the same stitch.