The main … If this resistance is not in place venous return is insufficient, compromising arterial supply to the head and resulting in a loss of consciousness. Mean skin thickness was 2.54 mm at the suprascapular, 2.02 mm at the … Skin samples from three giraffes were used in this study. 6A). 2). Please check your inbox, we have sent you the Download link, “More and more people are using masseter Botox t, Hyaluronic Acid (HA) is a ubiquitous component fou, Legacy #trump - a well documented #ageing process, Note: if you did not get the email, please check spam/junk folder, Biophysical Skin Changes - In-Depth Analysis. These are the lamina lucida and lamina densa. 1B). Many cosmetic procedures involve stimulating collagen production to increase skin firmness and to decrease visible signs of ageing. Working off-campus? 8). Consequently, the skin in these regions may be analogous to the antigravity suit, preventing arterial distension in the blood supply to the head. In the lower half of the lateral trunk, a band of superficial dermis containing a low density of elastic fibers was also prominent. Scale bar = 100 μm. Mast cells also have the ability to regulate interstitial substances surrounding connective tissue. In 3 females, the mean thickness was 1361.87 μm ± 43 μm on the control side, 1389.52 μm ± 45.1 μm at 2 weeks, 1862.55 μm ± 84.8 μm at 1 year, and 2066.70 μm ± 31.1 μm at 4 years. This is basically the layer between epidermis and hypodermis. The research by Dimond and Montagna (1975) and Mitchell and Skinner (2004) are the only two studies known to the authors that have described anatomical aspects of the skin of a giraffe. It supplies the epidermis with oxygen and important nutrients that make sure that epidermis survives. Protects the skin against harmful microorganisms. A previous study concluded that the average thickness of the skin in the head, neck, and legs was mostly uniform, but that the thickest skin was found in the trunk (Mitchell and Skinner, 2004). The greatest number of mast cells appear in dermis during the periods of intense interstitial substance formation that shows their important role in regulation. Long living fibroblasts basically have a supportive function. Eccrine glands are the ones responsible for the characteristic body odour unique to individuals. The average thickness of dermis is 0.5 mm to 4 mm. These include age, hormonal influence, medications and certain diseases. The range of the combined thickness of the epidermis and dermis should ideally be the same as those measured macroscopically; however, there is a slight difference with the microscopic measurements being slightly less than the macroscopic measurements (Table 1, Fig. The thickness of the skin varies considerably over all parts of the body, and between men and women and the young and the old. This is why when collagen is reduced in skin with age, firmness is also decreased. Botox eyebrow lift: Procedure, Cost, Effectiveness And Side Effects, Botox for migraine, Headaches and Teeth Clenching, Non-Surgical Face Lift | Jawline Filler & PDO Threads, I’ve done Botox with CosMedocs and was impressed with their service and professionalism. The average thickness of the deep dermis in the foreleg (2.28–4.47 mm) and hind leg (1.8–5.32 mm) was relatively consistent and much thinner than that of the neck, trunk, and rump (Fig. Endothelial cells are the specialized cells which control blood flow through the blood capillaries. Similar studies in other species of artiodactyl may determine whether these features of the skin of the giraffe are unique to this species, exaggerated patterns of a typical artiodactyl form, or merely representative of the typical artiodactyl morphology scaled to body proportions. In the other young and adult giraffes, spot tests to confirm the pattern observed in the fully analyzed individual were undertaken. The average thickness of the superficial dermis varied across the body regions (Table 1, Fig. Capillaries also have a very important role in thermoregulation. The deep dermis of the rostral aspect of the head contains a very low density of elastic fibers. With a thickness similar to that of a middle-level wrinkle, the dermis-subcutaneous junction under deep wrinkles (R max =1.16 mm) (Figure 3C) curved downward with invaginations of the dermis into the subcutaneous layer. Likewise, when the elastic fibres capacity is exceeded, injury may occur and this will need time for them to heal. This is of great cosmetic importance because it can change a person’s appearance and self-image. It provides mechanical protection to underlying structures and organs. It is a bag-like structure that nourishes the hair below the skin. Histological evaluation revealed that the skin was mostly collagenous, although interesting patterns of elastic fiber densities were also apparent. The average thickness of the superfi-cial and deep dermis was determined by calculating the average of the thinnest and thickest regions. The tissue was subsequently processed in a wax vacuum embedding machine for 2 hr and then embedded in wax blocks. For Contacting US. Mast cells are responsible for starting inflammatory reactions in skin in response to any injurious stimulus like physical or mechanical damage or microorganisms etc. We validated these observations with measurements and observations made in two other individuals by taking “spot tests” of regions of interest. (A) Taken from the lower foreleg shows a low density of elastic fibers; (B) taken from midlevel of the foreleg shows a very low density of fibers. It is thicker (averages 1 to 4 mm) than the epidermis which is about as thin as piece of paper. Dermis thickness (DT) is the universal scale parameter of electrically layered skin . The bundles of collagen fibres are interweaved in different directions. Dermis thickness (mm) Overall 2.18 (1.62–2.75) 2.37 (1.71–3.03) 0.70 Abdomen 2.21 (1.54–2.88) 2.76 (1.97–3.55) 0.33 RESULTS Thigh 2.16 (1.58–2.74) 1.97 (1.29–2.65) 0.70 Subcutis thickness We studied 18 adults aged 43.1 ± 16.5 years with a BMI of 2 (mm) 32.7 ± 6.0 kg/m . The rest of the sections were then assigned to a low‐, medium‐, or high‐density category of fibers. The skin of a giraffe is thick (approaching 20 mm at its thickest); however, when comparing it to that of other mammals more generally, it is not the thickest. Although it is well known that lion will kill giraffe (Pienaar, 1969), the authors cannot find the exact attack method described in the scientific literature; however, natural history documentaries often feature lions leaping onto the giraffe's back to pull it to the ground. Scale bar = 100 μm. This was accomplished by locating the sections showing the lowest and highest densities of fibers. Mean value of epidermis–dermis thickness (mm) according to body sites. While some of them work on epidermis solely and cause skin resurfacing, other stimulate dermis too. Dermis The dermis is located between the hypodermis and the epidermis. The thinnest superficial dermis was found in the trunk (0.47 mm), and this corresponded to one of the overall thickest regions of the skin. In this study of the giraffe, we found a large region of thick skin on the upper half of the trunk/rump and a substantially thickened deep dermal region on the anterior and lateral surfaces of the neck. In the llama, the skin is generally thick (mean = 3.9 mm), and the skin of the llama trunk increases in thickness ventrally to dorsally (Atlee et al., 1997). It is a fibrous network of tissue that provides structure and resilience to the skin. It can be assumed that variations of DT can strongly influence the current distribution and are mainly responsible for the observed interarea and intersubject variations of clinical results. Contrarilyto these results, the measurements of the skin thickness with MHz ultrasound in vivo provided the average DT values of about . This poses a gravitational challenge regarding the maintenance of sufficient cranial circulation (Goetz et al., 1960; van Citters et al., 1969; Mitchell et al., 2008), as insufficient blood supply to the head would result in fainting. Each strip was ∼10 cm in width but did vary with the curvature of the body surface. Learn more. Skin looks swollen when fluid leaks out of capillaries and accumulates in spaces between cells. A dramatic increase in thickness was observed in the neck (4.99–9.78) in comparison to the head. This is not the case in the rhinoceros, where skin thickness greatly exceeds that predicted by Calder's allometric equations (Shadwick et al., 1992). Body surface area and thermoregulation in giraffes. Despite this, it is most likely that the thickness of the giraffe skin on both the anterior neck and rump is related to protection from the thorns of the acacia trees on which it feeds. The dermis helps in the regulation of temperature and in supporting the functions of the epidermis through adequate supply of nutrients and oxygen, as described above. Charles van Niekerk, Martin Krogh, and the staff at Wildlife Assignments International are acknowledged for expert animal handling during the study. Conversely, the thickest superficial dermis was found in the foreleg and hind leg (1.67 mm) that corresponded to overall thinner regions of the skin. The average thickness of dermis is 0.5 mm to 4 mm. Interpolative manually smoothed maps of the variation in skin thickness based on measurements of skin thickness done macroscopically with sliding calipers (thickness of entire skin) and microscopically (thickness of deep and superficial dermis). There are two phases in a person’s life where there is accelerated growth in dermis thickness. Subscribe to our special offers, discounts, products and services. Calder (1984) produced a predictive allometric equation for the thickness of mammalian skin based on body mass, where skin thickness (mm) = 0.87 × mass0.29. This may have been the result of the inclusion of a layer of deep fascia when measuring macroscopically and/or the effect of the histological processes on the skin causing shrinkage. 2; all values provided come from specimen Gym1). This is especially clear in the case of the superficial dermis of the leg, which may form a cuff to support venous return, as first reported by Hargens et al. These include: The amount of sebum production can vary due to many factors. This is where you find blood capillaries, collagen, elastic fibres and reticular fibres. When this happens on the scalp, balding occurs and this is of concern to some people. Photomicrographs of sections of the superficial dermis of giraffe skin stained for collagen fibers using Van Gieson's technique. mm). It is very thick on the back (almost 1 cm); it is very thin on the eyelid. Therefore, when linking this to the possibility that thicker skin means tighter skin, the skin in the neck and trunk may be regarded as being tight. The skin in the neck and legs exhibited a morphology that may assist in cardiovascular regulation of blood flow to and from the head and legs, and the skin of the trunk and anterior neck has the possibility of functioning in a protective role. The neck and trunk of the giraffe consisted of the thickest overall skin. (B) Location from where blocks of skin were taken for histological analysis (small squares represent each location). Skin thickness may play a role in this, as overall skin thickness at patches was thicker than nonpatch skin by ∼100 μm (Mitchell and Skinner, 2004); however, it would appear that differences in other aspects of skin anatomy and physiology, such as blood vessels and sweat glands, would play a greater role in thermoregulatory mechanisms than skin thickness alone. Scale bar = 1 mm. Despite the association made between skin morphology in the giraffe and hemodynamics, thick skin in other large mammals has been related to the possibility of it forming dermal armor for protection against predators or during aggression from conspecifics. The dermis is divided into two layers. The superficial dermis of the rump, however, contained a high density of elastic fibers, and this may be related to flexibility of the hip joint. 2). The animals were treated in accordance to the University of the Witwatersrand Animal Ethics Committee guidelines for the care and use of animals in scientific experiments, and appropriate permissions for the use of the animal were also obtained from the Limpopo Provincial Governmental Department responsible for wildlife management. Photomicrographs of sections of the deep dermis of giraffe skin stained for elastic fibers using Verhoeff's method. 2) with the thinnest skin found at the knee in both legs. The remainder of the superficial dermis displayed a high density of collagen fibers with the exception of an area at the ventral surface at the junction of the neck and head tending toward a medium density (Fig. The thickest deep dermis (11.77 mm) was found in the trunk at the most lateral aspect. This was evident throughout the neck, the upper three quarters of the trunk, the midlateral surface of the rump, the proximal half of the tail, and the distal end of the foreleg and hind leg (Fig. It was evident that the thickness of the skin varied across the body surface (Fig. It forms the bulk of the dermis’ thickness. It is the layer which provides your skin with property of being sensitive. 8), this was not a significant feature of the deep dermal collagen fiber organization. Rashes actually occur when the blood flow increases through blood capillaries close to skin surface. Mitchell and Skinner (2004) have provided a full review of the thermoregulatory role of giraffe skin. As noted above, collagen maintains the bulk of the dermis. The two types of sweat glands are the apocrine and eccrine. All other spatial characteristics of the system, for example, distance between the electrodes, can be measured in the units of DT. These regions of increased skin thickness would allow the giraffe to move around in dense acacia vegetation and not suffer from cuts to the skin that would cause major openings and extensive bleeding. The histological examination of the skin revealed a very thin epidermis, a thicker superficial dermis and a very thick deep dermis. The DEJ consists of two layers. The arrowhead in each image indicates the border of the superficial and deep dermis (epidermal surface is up in each image). The dermis is made up of amorphous tissue that consists of fibres, matrix and cellular structures. Collagen fibers were found to occupy both dermal layers of the giraffe skin in high or very high densities in all the regions studied. In their review, Mitchell and Skinner pointed out that the skin thickness does vary in different regions of the body, with the trunk skin being the thickest, and their observations are confirmed and extended in this study. Normal bacteria that reside on the skin work on this glands secretion and this is what leads to the odour. Thus, despite the fact that the skin on the legs is thin, it may be regarded as tight because of the very high density of collagen fibers. One‐half of the entire skin was taken from Gym 1, and strips of skin covering legs, trunk, and neck were taken from Gym2 and Gam. The influence of resistances of ISDN and FP through the dermis-split rat or YMP skin was greater at 0.9 mm skin thickness than 0.4 mm skin thickness. It is divided into two layers, the superficial area adjacent to the epidermis called the papillary region and a deep thicker area known as the reticular dermis. It has been argued that a tight skin surrounding the extremities of the giraffe aids in the movement of fluid against gravity, hence preventing pooling of blood and tissue fluid (edema), but the skin has also been implicated in the thermoregulatory capacities and defensive anatomy of many mammalian species. Consequently, the giraffe has to counteract gravity in two ways to ensure adequate arterial supply to the head and venous return from the legs. Abdominal dermal thickness was not different between men and women (2.10 vs 1.99 mm; p = 0.16), but men had a thicker dermis on thighs compared to women (1.89 vs 1.65 mm; p = 0.003) . mm, .mm) []. This is however, only true where the spring’s tensile capacity is not exceeded. The later are found around the armpits and the groin. Using the Masson's trichrome technique, Mitchell and Skinner (2004) found that the skin was typically collagenous, making it inflexible and also suggested that the inflexibility of the skin impacted on tissue pressure, and this allowed the skin to provide resistance against high blood pressure. The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. Scale bar = 100 μm. The influence of resistances of ISDN and FP through the dermis-split rat or YMP skin was greater at 0.9 mm skin thickness than 0.4 mm skin thickness. Certain immunological disorders can affect this joint and give rise to chronic skin conditions that can lead to serious cosmetic concerns. The main goal of treatments acting on dermis is to enhance collagen production usually that improves skin firmness and youthfulness. Journal of the South African Veterinary Association. Spot tests of each of these stains were performed in regions of the skin in approximately the same region as those from Gym1 in both Gym2 and Gam, with similar results being obtained. Similarly, the giraffe would require tight skin around the neck, trunk, and legs to avoid edema and assist with venous return from the legs and prevent arterial distension of the supply to the head. The exact thicknesses (0.4, 0.9 mm) of the split rat skin samples were 0.41±0.02 mm and 0.85±0.04 mm, respectively. This layer is found just below the epidermis. This property helps keep skin firm. The major components of the dermis work together as a network. This varying thickness primarily represents a difference in dermal thickness, as epidermal thickness is rather constant throughout life and from one anatomic location to another. The patterns observed in Gym1 were confirmed in Gym2 and Gam. Photomicrographs of sections of the superficial dermis of giraffe skin stained for elastic fibers using Verhoeff's method. Basic functions of dermis The following histological stains adopted from Bancroft and Stevens (1982) were used: (1) Mayer's hematoxylin and eosin stain for collagen fibers (deep pink), elastic fibers (pink), and muscle (deep pink); (2) Verhoeff's method which stains for elastic fibers (black); (3) Weigert's resorcin fuchsin method which stains for elastic fibers (brown to purple); and (4) Van Gieson's technique which stains for collagen fibers (red). Please check your email for instructions on resetting your password. The dermis has two main zones, the papillary dermis and the reticular dermis. Measurements of the foreleg and hind leg revealed relatively thin skin (3–6.1 mm) (Table 1, Fig. The thickness of the superficial layer of the dermis exhibited a biphasic evolution with age and these variations were not significantly different between men and women because of the large individual variations. The thinnest skin — about 0.5 millimeter in thickness — is found on the eyelids, while the thickest skin, at about 4 mm, is on the palms of your hands and soles of your feet. © 2010 Wiley‐Liss, Inc. Despite this, the thickest portion of the skin of the giraffe is close to that seen in other large African mammals such as the white rhinoceros which has a skin thickness around 25 mm (Shadwick et al., 1992), the African elephant with a skin thickness close to 20 mm (Smith, 1890), and the hippopotamus which has a skin thickness up to 35 mm (Luck and Wright, 1964). The deep dermis of the lower lip and midlateral surface of the head consisted of collagen fibers with a medium density (Fig. This layer contains the main structures that support the skin’s functions. (A) Lateral view of giraffe body indicating the manner in which the skin was cut into strips for measurements. This is in early childhood and again at puberty. Variations with the individual, body site, sex and age are described and discussed. (A) Taken from the midrump shows a very high density of collagen fibers; (B) taken from midlevel of the neck shows a high density of fibers; and (C) taken from the midlevel of the head shows a medium level of fibers. The giraffe was found to demonstrate similarities to other species of this order that have been studied with respect to their skin. The split rat skin sample with a thickness of 0.4 or 0.9 mm was made by the electric dermatome. For some people, body odour is a source of continued stress but seeing a qualified cosmetologist and using the right cosmetic products can help to minimise this problem. Collagen fibers in the superficial dermis were a mixture of high and very high fiber densities (Figs. drawing program to illustrate the changes in thickness of these dermal layers. 1 to 4 mm BADLANGANA, and sebaceous and apocrine glands link below share... 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