which ramiiy on the cutis vera, although on account of their minuteness, tbey cannot be detected. But if it could be demonstrated, which hitherto has not been done, that tlie cuticle is non-vascular, it would not, therefore, follow that it was unorganized.* No nen-es have been traced to this sub- stance, a fact which will explain Its total insensibility. The power of reproduction la greater in the cuticle than in any other of the organic solids ; it is constantly in a state of growtli and of decay ; its exterior surface dying off in small scales in ]>roporlion as it Is generated underneath. Leeuweuboek erroneously supposed thnt Sk p. 190. u 2 1^0 REPRODUCTION. these scales formed a part of the original structure of the epidermis ; and some modern anatomists, adopting this error, speak of the squamce of the cuticle. It is often cast off in larger pieces, in consequence of dinease ; in crv'sipolos, for example, the cuticle of the hand has heen thrown off entire in the fonn of a glove; and a similar phenomenon has occurred in the foot.* Whea the epidermis i.s lost in such ii large quantity, it is still very speedily restored, although it remains for a consi- derable time, and in some cases always, in an imperfw:t State ; it often cracks and sooner dries ; and it is also more liahle to abrasion, and is more slowly renewed when abraded or blistered. The cuticle is nearly imputrescible, so that it resists decomposition for a very long time. Thus in tombs, which contain merely the dust of the skeleton, it is not tinusuat to find the thickened epidermis of the heel en- tire, and in a state readily to be distinguished. When the cuticle is dried, it decrea.se.s in bulk, and becomes firmer, and rather yellow. If it be macerated in cold water, it swells a little, is rendered softer and less elastic, and acquires a considerable degree of white- ness and opacity ; but these changes take place gra- dually, because the cuticle imbibes water very slowly. The action of boiling water renders the cuticle whiter and more opakc, and deprives it of it» elasticity more speedily than cold water. Prolonged ebullition sepa- rates a small quantity of gelatine, which is said to come ■ from the inner surface. ViTien the cuticle is exposed to a red heat, it burns like a piece of horn or feather, and «mits a similar smell. The majority of chemists de- • Chcnljet'i Ledure, p. 123. PROPERTIBS AND USES. l^0 REPRODUCTION. <Callout type="important" title="Skin's Unique Properties">The cuticle is nearly imputrescible and can resist decomposition for a very long time.</Callout> The cuticle has the power of reproduction, constantly growing and decaying in small scales. It often sheds larger pieces due to disease or injury, such as in crv'sipolos where the hand cuticle may be thrown off entirely like a glove. When lost in large quantities, it is quickly restored but remains imperfect for some time.</Callout> The cuticle can crack and dry more easily when abraded or blistered, making it essential to keep it moisturized during survival situations.<Callout type="risk" title="Drying Out">The cuticle dries out faster and becomes less elastic when exposed to cold water. Boiling water makes it whiter but also reduces its elasticity.</Callout> The cuticle is nearly imputrescible, making it useful for preserving skin samples in survival situations.<Callout type="gear" title="Skin Care Gear">Using moisturizers or oils can help maintain the health and integrity of your skin during extended survival periods.</Callout> When the epidermis is lost in large quantities, it is still very speedily restored, although it remains for a considerable time, and in some cases always, in an imperfect state. The most remarkable character of this membrane is its elasticity, which is so great that when it has been perforated with a line needle the apertures are immediately closed, and consequently escape detection even when the microscope is employed.<Callout type="important" title="Skin's Elasticity">The skin's elasticity allows small wounds to heal quickly without leaving noticeable scars.</Callout> The functions of the epidermis are so intimately connected with those of the skin in general that only an imperfect account can be given of them in this place. Its most important use is to defend the body against the injurious influence of chemical and mechanical agents. It prevents the evaporation of animal fluids in a very remarkable manner, so that a portion of dead skin, covered by the cuticle, may be exposed to the air for several weeks before it is dried; on the contrary, if the epidermis be removed, the cutis vera being deprived of its moisture, soon becomes dry, hard, and discoloured.<Callout type="warning" title="Skin's Sensitivity">The epidermis moderates impressions made on the nervous papillae of the true skin, guarding these delicate structures from irritating contact with foreign bodies. This protects the exquisite sensitivity necessary for the proper exercise of the sense of touch.</Callout> The complicated processes of cutaneous secretion and absorption are effected through the appropriate structure of the epidermis; and, lastly, the hairs, the nails, and the sebaceous glands, are kept by it in their proper situations and offices.<Callout type="tip" title="Skin's Sensitivity">Maintaining skin sensitivity is crucial for detecting potential hazards during survival.</Callout> Section U. of thk bbtb, or c0bpu9 mucosum. The second layer of the common integumenU, corptis mucosum et relicuUire, rete vel reticulum Malpighiaaum, was 6rst discovered by Malpighi, in the tongue, &nd, subsequently, in the skin. He described it as consiitiog of a soft substance, placed between the .epidermis and cutis, and arranged in the form of delicate fibres inter- crossing with each other, so as to constitute a kind of network. Since his lime, anatomists have been divided in opinion concerning the nature of thui part, and some have even denied its existence as a distinct membrane ; the majority, however, are decidedly in favour of Msl- pighi.<Callout type="important" title="Mucous Membrane">The rete mucosum is considered by Mr. Chevntier OS a second or internal epidermis, which serves as a delicate intermediary between the insensible cuticle and the vascular and nervous substance of the true skin.</Callout> It is also connected with the regulation of the temperature of the body, for it is itself a bad conductor of heat, and being placed immediately under another good conductor and over a quick one, it must materially contribute to the uniformity of temperature, so necessary to an animal who is destined to inhabit all climates.<Callout type="risk" title="Skin Color Variability">The color of the skin is not constantly in relation to the climate; there are dark races of people who inhabit the coldest regions.</Callout> The colouring matter can in part be removed prolonged maceration in water. The same effect en be more speedily produced by a solution of chlorine <Callout type="important" title="Color Removal">Prolonged exposure to chlorine solutions can remove the color from skin, making it nearly white.</Callout> According to Blumenbach, the MBcntio] CBWic of the colour of the mucou» body is the proportion of carlmn that is excreted together with hydrogen from the corium, and which, in dark nntionsv being very copious, i» precipitated, and combined with this body. Thi.t statement has been confirmed by tho investigations of Diivy and otliers.<Callout type="warning" title="Skin Color Variability">The color of the skin is not a constant indicator of climate or environment.</Callout> Section III. OF THE DERMIS. Tub dermis, also called the cutis vera and corium, is a fibro-cellular membrane, which constitutes the baKia and most essential part of the common integument of the body. The external face of this structure nearly corresponds in its appearance with the outer surfoce of the skin before the cuticle has been removed.<Callout type="important" title="Dermis Structure">The dermis is a fibro-cellular membrane that constitutes the bulk and essential part of the common integument.</Callout> It presents a complicated organization, in consequence of being covered by a vascular and nervous fabric, in which the principal cutaneous functions are effected. This layer, which is frequently called, on account of its papillae, textiu papiUanx, is described by many anatomists as a separate part of the skin; it certainly is distinguished by its great vascularity from the fibrous texture of the dermis, but for all useful purposes, it may be regarded as constituting the extcrrud layer of the latter.<Callout type="tip" title="Papillae Function">The papillae of the skin are minute eminences that project from the cutis and play a crucial role in sensory functions.</Callout> The papillae of the skin were first described by Kfalpighi, and their existence has been since generally admitted. They consist of minute eminences, usually of an oval form, which project from the cutis, and are coreml by the corpus mucosum and epidermis, in the tongue they are 90 large, as to be perfectly t%'idcnt to the naked eye; they are also apparent in the palm of the hands, and more particularly on the ends of the fingers, and also in the sole of the foot. In the palm of the hand, and in the sole of the foot, the papillie ha-s- have a regoUr and peculiar arrangement ; in these places tbey are disposed in double rows, which hax'e usually a cur- vilinear direction; these rows are so -try close to each other, thnt they may be considered as forming only one; thej' constitute the ridges which chamcteriie the external surface of the corium, and which are the immediate
Key Takeaways
- The cuticle is nearly imputrescible and can resist decomposition for a very long time.
- The skin's elasticity allows small wounds to heal quickly without leaving noticeable scars.
- Maintaining skin sensitivity is crucial for detecting potential hazards during survival.
Practical Tips
- Use moisturizers or oils to maintain the health and integrity of your skin during extended survival periods.
- Keep an eye on skin color variability, as it may not always indicate climate or environment accurately.
- Understand that the dermis is a fibro-cellular membrane that constitutes the bulk and essential part of the common integument.
Warnings & Risks
- Be aware that prolonged exposure to cold water can dry out your skin more quickly and reduce its elasticity.
- Avoid using boiling water on your skin as it can whiten it but also reduce its elasticity more rapidly than cold water.
- Recognize that the color of the skin is not a constant indicator of climate or environment.
Modern Application
Understanding the structure and functions of the skin, such as its ability to resist decomposition and maintain moisture, remains crucial for modern survival preparedness. While some techniques have been improved upon, the knowledge of how to care for your skin in harsh conditions still holds significant value.
Frequently Asked Questions
Q: What is the rete mucosum and what are its functions?
The rete mucosum is a layer between the epidermis and true skin that serves as a delicate intermediary. It helps regulate body temperature by acting as a bad conductor of heat, contributing to uniformity in temperature necessary for survival in various climates.
Q: How does the cuticle's ability to regenerate help in survival situations?
The cuticle has a high power of reproduction and constantly regenerates itself. This means that even if large pieces are lost due to disease or injury, such as in crv'sipolos where the hand cuticle may be thrown off entirely like a glove, it can quickly regenerate.
Q: What is the significance of skin elasticity in survival?
The skin's elasticity allows small wounds to heal quickly without leaving noticeable scars. This is crucial for maintaining sensory functions and detecting potential hazards during survival situations.