Journal of anatomy
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Comparative Study
Computer-assisted stereological analysis of gastric volume during the human embryonic period.
Morphometric data concerning human embryos and fetuses have become more clinically informative since ultrasound was employed to make prenatal measurements and software preprocessing techniques improved the previous fuzzy ultrasound signals (Mahoney, 1992). The aim of this study was to determine the volume of the human stomach during the embryonic period and to compare its rate of growth with that during the early fetal period. To calculate gastric volume, computer imaging techniques were applied on cross sections of a graded series of human embryos (from Carnegie stage 11) and fetuses. ⋯ Until stage 20 the stomach volume increased due to the predominant growth of the walls, after this stage the gastric cavity volume increased rapidly, and the rate of growth of the gastric volume reached similar values to that of the early fetal period. We concluded that in the beginning the human stomach grows due to the predominant growth of its walls, chiefly of the left, and from stage 20 because of the predominant expansion of its cavity, which may be related to the capacity to swallow amniotic fluid at the end of the embryonic period. The diminution of the right gastric wall volume (stages 12-13) is consistent with an extension of the omental bursa into the mesodermal anlage of the stomach.
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Nerve ischaemia plays a major role in the development of pathological alterations in various neuropathies, and the effects of ischaemia are amplified by reperfusion in various tissues. While pathological alterations in acutely ischaemic nerve have been established, nerve pathology resulting from reperfusion injury has never been elucidated. To evaluate what cell type in peripheral nerve is affected by reoxygenation following a hypoxic episode, we developed an animal model of transient severe limb ischaemia. ⋯ Swollen endothelial cells in endoneurial vessels were also invariably observed. Nerve ischaemia per se, without reperfusion, did not induce these pathological changes. Because myelin appears to be particularly susceptible to activated free radicals, oxidative stress, activated neutrophils, and cytokine formation seem to be important underlying mechanisms in the development of perivascular demyelination and intramyelinic oedema in ischaemic/reperfused nerves.(ABSTRACT TRUNCATED AT 250 WORDS)
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The cutaneous branch of the suprascapular nerve was studied bilaterally in 34 adult cadavers. In 5 the suprascapular nerve derived its fibres from the ventral rami of the 4th, 5th and 6th cervical nerves. The cutaneous branch was observed in 14.7% of the 68 limbs examined. ⋯ After passing deep to the acromioclavicular ligament, the cutaneous branch bent forward near the tip of the acromion process and pierced the deltoid muscle close to its origin and came to lie deep to the deep fascia. In the subcutaneous tissue, it divided into 3-4 twigs and supplied the proximal third of the lateral aspect of the arm within the territory of the axillary nerve. Presumably in normal human arms the cutaneous component of the suprascapular nerve is contained within the axillary nerve.
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Sixty-five Nigerian and 34 Indian adult human skulls with full eruption of the 3rd molar teeth were examined to ascertain the location of the greater palatine foramen. The location of the foramen from the posterior border of the hard palate was quite consistent, being 0.35 cm in Nigerian and 0.37 cm in Indian skulls. The usually accepted description as opposite the upper 2nd molar was observed for only 13.1% of foramina in Nigerian skulls. ⋯ In 38.5% Nigerian skulls the opening was in an anterolateral direction. A bilaterally symmetric bony projection extending from the posterior margin of the foramen was observed in 24.6% of the Nigerian and 35.3% of Indian skulls. The palatal vault of was U-shaped in all instances, its height varying from flat to 0.3-0.8 cm.