Volume 1

A textbook of human physiology / / translated from [the] 7th German edition by William Stirling.

  • Landois, Leonard
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: A textbook of human physiology / / translated from [the] 7th German edition by William Stirling. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    596/602 (page 556)
    Head.—The secretory fibres Eor this part (horse, man, snout of pig) lie iu the sympathetac (§ 356, A.). Percutaneous electrical stimulation of the cervical sym- pathetic m man causes sweating of that side of the face and of the arm (M m3% In the cephalic portion of the sympathetic, some of the fibres' puss into or beSe S SirL J! branCllCS °f thC trigemimiS' Which Why stinmlatr of the infraorbital nerve causes secretion of sweat. Some fibres, however arise lSS£S. r°0tS th° trig0minUS (Luch^h and the facial (Vulpian, Undoubtedly the cerebrum has a direct effect either upon the vaso-motor nerves (p. 5o4, L) or upon the sweat-secretory fibres (II.), as in the sweating produced by psychical excitement (pain, fear, &c). ' thef^^S ^f1 S.?at°r f°x?d that' in a mm suffe»»g fr°m abscess of the motor region of the coi fcex cerebri lor the arm, there were spasms and perspiration in the arm. Sweat-centre.—According to Adamkiewicz, the medulla oblongata contains the dominating sweat-centre (§ 373). When this centre is stimulated in a cat, all the four feet sweat, even three-quarters of an hour after death (Adamkiewicz). III. The nerve-fibres which terminate in the smooth muscular fibres of the sweat- glands act upon the excretion of the secretion. Other conditions.—If the sweat-nerves be divided (cat), injection bf pitocarpin causes a secre- tion of sweat, even at the end of three days. After a longer period than six days there may be no secretion at all. This observation coincides with the phenomenon of dryness of the skin in paralysed limbs. Dieffenbach found that transplanted portions of skin first be^an to sweat when their sensibility was restored. Experiments on man.—If a motor nerve (tibial, median, facial) of a man be stimulated, sweat appears on the skin over the muscular area supplied by the nerve, and also upon the correspond- ing area of the opposite non-stimulated side of the body. This result occurs when the cireula-- tion is arrested as well as when it is active. Sensory and thermal stimulation of the skin always cause a bilateral reflex secretion independently of the circulation. The area of sweating is independent of the part of the skin stimulated. [Changes in the CeUs during Secretion.—In the resting glands of the horse, the cylindrical cells are clear with the nucleus near their attached ends, but after free perspiration they become granular, and their nucleus is more central (Rcnaut).~\ 288. PATHOLOGICAL VARIATIONS. —1. Anidrosis or diminution of the secretion of sweat occurs in diabetes and the cancerous cachexia, and along with other disturbances of nutrition of the skin in some nervous diseases, e.g., in dementia paralytica ; in some limited regions of the skin, it has occurred in certain tropho-neuroses, e.g., in unilateral atrophy of the face and in paralysed parts. In many of these cases it depends upon paralysis of the corresponding nerves or their spinal sweat-centres. 2. Hyperidrosi8, or increase of the secretion of sweat, occurs in easily excitable persons, in consequence of the irritation of the nerves concerned (§ 287), e.g., the sweating which occurs in debilitated conditions and in the hysterical (sometimes on the head and hands), and the so- called epileptoid sweats (Eulenburg). Sometimes the increase is confined to one side of the licad (H. unilateralis). This condition is often accompanied with other nervous phenomena, partly with the symptoms of paralysis of the cervical sympathetic (redness of the face, narrow pupil), partly with symptoms of stimulation of the sympathetic (dilated pupil, exophthalmos). It may occur without these phenomena, and is due perhaps to stimulation of the proper secretory fibres alone. [Increased sweating is very marked in certain fevers, both during their course and at the crisis in some ; while the sweat is not only copious but acid in acute rheumatism. The night-sweats of phthisis are very marked and disagreeable.] 3. Paridrosis or qualitative changes in the secretion of sweat, e.g., the rare case of sweating of blood (haamatohidrosis), is sometimes unilateral. According to Hebra, in some cases tins condition represents a vicarious form of menstruation. It is, however, usually one of many phenomena of nervous affections. Bloody sweat sometimes occurs in yellow fever. Bile- pigments have been found in the sweat in jaundice ; blue sweat from indigo (Bizio), from pyocyanin (the rare blue colouring-matter of pus), or from phosphate of the oxide of iron (Osc. Kallmann) is extremely rare. Such coloured sweats are called chromidroses. Numerous micro- organisms (which, however, are innocuous) live between the epidermal scales and on tho hairs, two varieties of Saccharomycetes ; in cutaneous folds Leptothrix epidermalis, various Schizo- mycetes, and five kinds of Micrococci ; and between tho toes—Bacterium graveolcns {Bordoui-