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сухожилия часть мышц, но не мышечные ткани. В пальцах именно жировая ткань, так что Ваше предположение неверное.
По поводу рефлекса:
However, it has long been known that cuts to sympathetic innervation to a finger abolish the wrinkling response to wetness [Lewis and Pickering, 1936; O’Riain, 1973; Bull and Henry, 1977; Braham et al., 1979; Alvarez et al., 1980; Vasudevan et al., 2000; Hsieh et al., 2006, 2007; Tindall et al., 2006], which has led to suggestions to use the wrinkling response as a simple test for sympathetic integrity in unresponsive patients. For example, Vasudevan et al. [2000] showed that blocking the sympathetic response, either temporarily via lumbar epidural infusion or permanently via chemical or surgical cervical sympathectomy, terminated the wet-wrinkling response. Wilder-Smith [2004] provides evidence that the finger-wrinkling mechanism may be due to digit pulp vasoconstriction: wet-induced wrinkles are accompanied by vasoconstriction [Wilder-Smith and Chow, 2003a], and wrinkles are induced by vasoconstrictive agents [Wilder-Smith and Chow, 2003b; Wilder-Smith, 2004].
References
Alvarez G, Eurolo J, Canales P (1980): Finger wrinkling after immersion in water. Br Med J 281:585–586.
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Crossref (DOI)
Braham J, Sadeh M, Saravoa-Pinhas I (1979): Skin wrinkling on immersion of hands: a test of sympathetic function. Arch Neurol 36:113–114.
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Bull C, Henry JA (1977): Finger wrinkling: a test of autonomic function. Br Med J 1:551–552.
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Crossref (DOI)
Chemical Abstracts Service (CAS)
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Cales L, Weber RA (1997): Effects of water temperature on skin wrinkling. J Hand Surg Am 22:747–749.
External Resources
Pubmed/Medline (NLM)
Crossref (DOI)
Chemical Abstracts Service (CAS)
Cambridge Scientific Abstracts (CSA)
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Changizi MA (2001): The economy of the shape of limbed animals. Biol Cybern 84:23–29.
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Crossref (DOI)
Chemical Abstracts Service (CAS)
Cambridge Scientific Abstracts (CSA)
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Changizi MA, Cherniak C (2000): Modeling the large-scale geometry of human coronary arteries. Can J Physiol Pharmacol 78:603–611.
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Cherniak C, Changizi MA, Kang D (1999): Large-scale optimization of neuron arbors. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 59:6001–6009.
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Crossref (DOI)
Chemical Abstracts Service (CAS)
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Hsieh CH, Huang KF, Liliang PC, Huang PC, Shih HM, Rau CS (2007): EMLA and water immersion cause similar vasodilatation in replanted fingers. J Surg Res 143:265–269.
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Hsieh CH, Huang KF, Liliang PC, Jeng SF, Tsai HH (2006): Paradoxical response to water immersion in replanted fingers. Clin Auton Res 16:223–227.
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Crossref (DOI)
ISI Web of Science
Lewis T, Pickering GW (1936): Circulatory changes in fingers in some diseases of the nervous system, with special reference to digital atrophy of peripheral nerve lesions. Clin Sci 2:149.
O’Riain S (1973): A new and simple test of nerve function in hand. Br Med J 3:615–616.
External Resources
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Crossref (DOI)
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Tindall A, Dawood R, Povlsen B (2006): Case of the month: the skin wrinkle test – a simple nerve injury test for paediatric and uncooperative patients. Emerg Med J 23:883–886.
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Crossref (DOI)
Chemical Abstracts Service (CAS)
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Tsai N, Kirkham S (2005): Fingertip skin wrinkling – the effect of varying tonicity. J Hand Surg Br 30:273–275.
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Chemical Abstracts Service (CAS)
Vasudevan TM, van Ru AM, Nukada H, Taylor PK (2000): Skin wrinkling for the assessment of sympathetic function in the limbs. Aust NZ J Surg 70:57–59.
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Crossref (DOI)
Chemical Abstracts Service (CAS)
Wilder-Smith EP (2004): Water immersion wrinkling: physiology and use as an indicator of sympathetic function. Clin Auton Res 14:125–131.
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Crossref (DOI)
ISI Web of Science
Wilder-Smith EP, Chow A (2003a): Water immersion and EMLA cause similar digit skin wrinkling and vasoconstriction. Microvasc Res 66:68–72.
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Wilder-Smith EP, Chow A (2003b): Water-immersion wrinkling is due to vasoconstriction. Muscle Nerve 27:307–311.
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Crossref (DOI)
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Тут ссылки на многие статьи, сами статьи тут приложить функции нету, но, подозреваю, часть из них можно скачать без проблем.