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At least 307 records · Page 17Linked to original sources
PubMed1983

[The Tae Yang (V) and Tou Mo (VG) meridians as vestiges of embryonic structures. Acupuncture as embryo reflex therapy: a new theory].

A new theory for the understanding of the therapeutic results of two channels of Chinese Acupuncture: Urinary Bladder (U.B.) and Tou Mo. It is possible to underline that these two channels represent in the adult the trace of anatomical structures present in the human embryo. The series of medial posterior branches at their skin output are the Yu points where the myotomic slides split in their epiaxial and hypoaxial parts (statural and kinetic muscles). Tou Mo channel is the adult trace of the embryonic primitive line.

Acupuncture Therapy↗
PubMed1989

Pars plana and ora serrata anatomotopographic study of fetal eyes.

Morphology and topographic anatomical relations of pars plana, pars plicata and ora serrata were examined in 15 globes of fetuses, obtained from autopsy. The mean value of pars plana size was: nasal meridian = 1.15 +/- 0.32 mm; temporal meridian = 1.20 +/- 0.34 mm; superior meridian = 1.19 +/- 0.34 mm; inferior meridian = 1.15 +/- 0.34 mm. The mean value of the distance between the sclerocorneal limbus and the ora serrata was: nasal meridian = 3.22 +/- 0.30 mm; temporal meridian = 3.33 +/- 0.35 mm; superior meridian = 3.23 +/- 0.36 mm; and inferior meridian = 3.27 +/- 0.37 mm. A significant difference between the mean sizes of the pars plana in the superior meridian was found compared to the nasal and inferior meridian. The distances from Schwalbe's line to the ora serrata in the 4 meridians did not vary significantly. A positive, significant correlation between the antero-posterior diameter and the distances from the sclerocorneal limbus to the ora serrata was demonstrated in the 4 meridians.

Eye↗
PubMed1980

Second and third visual areas of the cat: interindividual variability in retinotopic arrangement and cortical location.

1. The cortical location and the retinotopic arrangement of the second (V2) and third (V3) visual areas in the cat have been investigated with single and multiple unit recordings in anaesthetized and immobilized animals.2. V2 and V3 are arranged side by side anterior and medial to V1 and occupy the lateral gyrus and the postlateral sulcus. In addition, V2 spreads to postlateral parts of the lateral sulcus and, occasionally, to the posterior suprasylvian gyrus. The contralateral lower hemifield is represented on the lateral gyrus, the area centralis and the horizontal meridian are found in most animals in the anterior part of the postlateral sulcus, and the representation of the upper hemifield occupies the posterior part of the postlateral sulcus.3. The detailed retinotopic arrangement of the visual field maps shows two characteristic features. First, the retinotopy at the V2/V3 border differs between lower and upper hemifield. In the lower hemifield the periphery of the fields is represented, whereas in the upper hemifield the border between the representations is formed by a sector running along the horizontal meridian about 5-10 degrees in the upper hemifield. Thus the lower field arrangement resembles that of rodents, and the upper field arrangement is similar to that of primates. Secondly, the periphery of a part of the visual field is not continuously represented, but forms patches or islands (Donaldson & Whitteridge, 1977). The islands are bounded by visual field representations closer to the vertical meridian. The way the visual field is represented at the border between V2 and V3 introduces discontinuities into the visual field maps: adjacent parts of the visual field are not represented adjacently in these two prestriate areas.4. Cortical location and detailed retinotopic arrangement vary considerably from animal to animal, so that a representative map of V2 and V3 cannot be constructed. For example, the representation of the periphery of the horizontal meridian may be located either in the anterior portion of the postlateral sulcus or some mm more posteriorly, where the sulcus turns laterally. The representation of the area centralis in V3 is found either at the transition zone between lateral and postlateral sulcus, on the posterior suprasylvian gyrus, or in the posterior part of the postlateral sulcus.5. The entire hemifield is represented in V2 at least in some animals. In V3 the uppermost part of the vertical meridian seems not to be represented. In other animals only a restricted part of the contralateral visual field is represented in V2 or in V3. In these cases the receptive fields cover not more than 50 degrees out in the lower hemifield or on the horizontal meridian. In a few cases the periphery of the horizontal meridian and the upper hemifield are not at all represented in V3, or only in an incomplete manner.6. The magnification factors (Daniel & Whitteridge, 1961) become progressively smaller from V1 to V2 to V3. Hence cortical volume occupied decreases from V1 to V3. In V1 and in V2 the magnification is highest along the lower vertical meridian. In V2 the magnification along the horizontal meridian is the smallest, whereas in V1 the magnification decreases progressively from the lower vertical, to the horizontal and to the upper vertical meridian. The relationship between retinal ganglion cell densities and cortical magnification factors is discussed.

Animals↗
PubMed1996

Intense peripheral electrical stimulation differentially inhibits tail vs. limb withdrawal reflexes in the rat.

In an on-going study on mechanisms by which activation of sensory afferents regulates nociception, high-intensity, low-frequency electrical stimulation was applied to previously defined meridian and non-meridian points of the hindlimb or forelimb, and the effects measured on the withdrawal reflex of the tail or limb in the lightly anesthetized rat. Withdrawal was evoked by application of noxious radiant heat to the tip of the tail or to the plantar surface of a hindpaw or forepaw. Parameters of conditioning electrical stimulation were 2 ms pulses at 4 Hz for 20 min at 20 x threshold (20-30 mA) where threshold was the minimum intensity which evoked muscle twitch. In experiments on tail withdrawal, stimulation applied to meridian points fengshi (GB-31), femur-futu (ST-32) and zusanli (ST-36) of the hindlimb or to wai-kuan (TH-5) and hoku (LI-4) of the forelimb increased the latency of the withdrawal reflex to 70-100% of the maximum possible inhibition (MPI) during the stimulation. Inhibition persisted for more than 1 h after the end of stimulation. Bilateral stimulation of hindlimb meridian points evoked a greater inhibition during the stimulation (> 95% of the MPI); the inhibition persisted for 40 min. Stimulation of non-meridian sites in hindlimb or forelimb inhibited the withdrawal reflexes by 45-50% of the MPI during the stimulation only. Thus, the evoked inhibition has two components, a brief effect elicited by non-meridian point stimulation and a persistent post-stimulation effect produced only upon stimulation of meridian points. Stimulation produced little effect on nociceptive limb withdrawal reflexes. The results suggest that high-intensity, low-frequency electrical stimulation of meridian points produced a long-lasting, extrasegmental inhibition of the tail withdrawal but not of limb withdrawal reflexes. This differential inhibition may be due to differences in neuronal circuitry and CNS modulatory control mechanisms. The persistent inhibition appears to be dependent on the site of stimulation because it is not evoked by stimulation of sites outside of meridian points.

Anesthesia↗
PubMed1998

Signs of surface torsion and torsional dioptric power.

Although there is agreement in the literature over the magnitude of torsion and torsional dioptric power, there is ambiguity over the signs of those quantities. The purpose of this paper is to define terms in such a way that the ambiguity is removed. Explicit equations are presented for torsion and torsional power along a meridian of a surface. In keeping with common practice in other disciplines, right-handed torsion is chosen to be positive. The components of the dioptric power matrix of thin systems and of the reduced vergence matrix are reinterpreted in terms of curvital and torsional power. In this reinterpretation the off-diagonal components of the matrices remain the torsional power and the reduced torsion along the meridian orthogonal to the reference meridian. However, they become the negatives of those quantities along the reference meridian. In particular, the top-right component can be interpreted as the reduced torsion or the torsional power along the meridian orthogonal to the reference meridian and the bottom-left as the negative of those quantities along the reference meridian. Torsion and torsional power along a meridian, as well as curvature and curvital power, are invariant under change of reference meridian and under spherocylindrical transposition.

Eyeglasses↗
PubMed2004

Qualitative effect of zonular tension on freshly extracted intact human crystalline lenses: implications for the mechanism of accommodation.

PURPOSE: To determine the topographic effects of zonular tension on the anterior surface of the human crystalline lens. METHODS: Real-time topography of the anterior surface of seven fully relaxed, freshly extracted intact, clear, human crystalline lenses aged 3, 17, 45, 54, 54, 56, and 56 years was qualitatively obtained before, during, and after the application of zonular traction. Zonular traction was applied manually either by grasping a group of zonules 180 degrees apart with tying forceps (three lenses), or with micrometers by clamping four portions of the ciliary body that were 90 degrees apart (four lenses). RESULTS: Zonular tension began with the lenses in the fully relaxed, baseline state. As zonular tension was increased across one meridian of all seven lenses, the center of the anterior surface steepened while the periphery of the anterior surface flattened across that meridian of traction. When the tension was reduced across that meridian of traction, the center of the lens flattened while the periphery steepened in that meridian. Four-point zonular traction applied 90 degrees apart produced symmetrical central steepening (four lenses). Reduction of zonular tension across both orthogonal meridians caused symmetrical central flattening. CONCLUSIONS: These observations reveal that when zonular tension is applied to the fully relaxed lens, the center steepens and its periphery flattens in the meridian (or meridians) in which zonular tension is applied. The reverse of this process demonstrates that as tension is reduced, the center of the lens flattens while the periphery steepens either in the meridian of relaxation or symmetrically when zonular tension is released from two orthogonal meridians. These results are opposite to what would have been predicted on the basis of Helmholtz's theory of accommodation.

Accommodation, Ocular↗
PubMed1977

Abnormal interhemispheric connections in the visual system of Boston Siamese cats: a physiological study.

In the normal cat most visual fibers in the splenium of the corpus callosum are concerned with a representation of the vertical meridian of the visual field. These fibers for the most part originate from cortical regions forming the border between adjacent architectonic areas, such as the anatomical 17-18 border. Due to a genetic mutation in Boston Siamese cats, the anatomical 17-18 border now represents a region in the ipsilateral visual field roughly 20 degrees away from the vertical meridian, and the representation of the vertical midline is displaced from the border to regions within areas 17 and 18 proper. Do visual fibers in the Boston Siamese cat corpus callosum originate, as in normal cats, from the 17-18 border even though the vertical meridian is no longer represented there? The present paper deals with this question from a physiological standpoint. Single visual fibers in the corpus callosum of 11 Boston Siamese and two normal cats were recorded using extracellular microelectrodes. Receptive fields were mapped and their positions used to infer the likely cortical site of origin for each fiber. In confirmation of earlier findings, most callosal receptive fields in the normal cat were closely apposed to the vertical meridian, as would be expected if only those visual cortical regions which represent the vertical meridian, such as the border between areas 17 and 18, contribute to the corpus callosum. In Boston Siamese cats, however, an abnormally large amount of visual field was represented in the corpus callosum, with some receptive fields located as far as 25 degrees away from the vertical meridian. The representation of the vertical meridian was nevertheless substantial. The present findings suggest, therefore, that in Boston Siamese cats callosal fibers do not originate solely from the boundary regions between adjacent cortical areas, such as the anatomical 17-18 border, but originate also from other cortical regions, especially the vertical meridian representation, regardless of their location with respect to such boundaries.

Animals↗