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The effects of androgens on human skin mainly include the regulation of growth and differentiation of hair follicles and sebaceous glands. Androgens may have some physiological roles in sheep skin that are similar to those of humans, but further confirmation is needed. Therefore, Hetian sheep were chosen in this study as an animal model to explore the effects of testosterone on skin structure and factors related to androgen conversion and binding in Hetian sheep. The sheep were treated with different concentrations of testosterone for 42 days. Skin tissue sections were prepared and then subjected to hematoxylin–eosin, Sacpic, Masson’s trichrome, and Oil Red O staining to observe changes in skin morphology. Changes in the content of blood-related factors were also detected using ELISA kits. The skin tissue distribution of androgen receptor was explored by immunohistochemistry and immunofluorescence assays. The results showed that testosterone significantly increases the sebaceous gland area and stimulates the formation of new sebaceous glands. Further exploration revealed that testosterone promotes the proliferation of sebaceous gland juvenile cells. However, testosterone was found to have no significant effect on hair follicle density and hair follicle structure. Testosterone increased dihydrotestosterone levels but decreased 5α-reductase 1 and 5α-reductase 2 levels. The androgen receptors were distributed in the hair follicles, sebaceous glands, and some major skin appendages of Hetian sheep. This study suggests that androgens can be effective in regulating sebum production in sheep. This study will help advance research efforts to further explore the molecular and cellular mechanisms by which androgens modify sheep follicles and sebaceous glands. [ABSTRACT FROM AUTHOR]

This study compares the skin structures of Rana kukunoris with two different skin colors living in the same area of Haibei in the Northeastern Qinghai-Tibet Plateau. The skin thickness of the khaki R. kukunoris was significantly greater than that of the brown R. kukunoris (P < 0.01), and significantly more mucous and granular glands were present on the dorsal skin of the khaki frog (P < 0.05). Meanwhile, the melanocytes on the dorsal skin of the brown frog were significantly larger than those on the khaki one (P < 0.05). Morphological changes in the expansion and aggregation of melanocytes seemed to deepen the skin color of R. kukunoris. Moreover, transcriptome sequencing identified tyrosine metabolism, melanogenesis, and riboflavin metabolism as the main pathways involved in melanin formation and metabolism in brown R. kukunoris. TYR, MC1R was upregulated as the skin color of R. kukunoris was deepened and contributed to melanin production and metabolism. In contrast, the khaki frog had significantly more upregulated genes and metabolic pathways related to autoimmunity. The khaki frog appeared to defend against ultraviolet (UV) radiation-induced damage by secreting mucus and small molecular peptides, whereas the brown frog protected itself by distributing a large amount of melanin. Hence, the different skin colors of R. kukunoris might represent different adaptation strategies for survival in the intense UV radiation environment of the Qinghai-Tibet Plateau. Figure. Individuals, Paraffin sections, Comparison of the morphological characteristics and the differentially expressed genes of R. kukunoris with different skin colors. [Display omitted] • The skin thickness of the khaki Rana kukunoris is greater than brown one • TYR and MC1R have different expression • Different skin colors are adaptation strategies to survive intense UV radiation [ABSTRACT FROM AUTHOR]

Excavation of burrows is an extremely physically demanding activity producing a large amount of metabolic heat. Dissipation of its surplus is crucial to avoid the risk of overheating, but in subterranean mammals it is complicated due to the absence of notable body extremities and high humidity in their burrows. IR-thermography in a previous study on two species of African mole-rats revealed that body heat was dissipated mainly through the ventral body part, which is notably less furred. Here, we analyzed the dorsal and ventral skin morphology, to test if dermal characteristics could contribute to higher heat dissipation through the ventral body part. The thickness of the epidermis and dermis and the presence, extent and connectivity of fat tissue in the dermis were examined using routine histological methods, while vascular density was evaluated using fluorescent dye and confocal microscopy in the giant mole-rat Fukomys mechowii. As in other hitherto studied subterranean mammals, no subcutaneous adipose tissue was found. All examined skin characteristics were very similar for both dorsal and ventral regions: relative content of adipose tissue in the dermis (14.4 ± 3.7% dorsally and 11.0 ± 4.0% ventrally), connectivity of dermal fat (98.5 ± 2.8% and 95.5 ± 6.8%), vascular density (26.5 ± 3.3% and 22.7 ± 2.3%). Absence of large differences in measured characteristics between particular body regions indicates that the thermal windows are determined mainly by the pelage characteristics.

The semi‐arid region (Caatinga), that corresponds to 18.26% (1,540,000 km2) of Brazil, occupies most the northeast region. Rainfall is irregular and concentrated within the first 3 months of the year. Prolonged periods of drought, with low total rainfall, may extend for two or more years. Most of the rivers of this biome are temporary, remaining totally dry during periods of drought. We collected and observed the natural history and biology of the species Proceratophrys cristiceps, Pleurodema diplolister and Physalaemus spp, both in the rainy and dry seasons, in ten field expeditions to the State of Rio Grande do Norte (Brazil). We focused on the morphology of the skin and cutaneous glands, specifically in their defence against desiccation. During the dry season, they form concentrations in the bed of temporary rivers, burrowing themselves in favourable locations within the sand, at depths that may exceed 1.50 m. No morphological evidence was found that there are specific cutaneous adaptations against water loss. We suggest that the cutaneous fragility per se is a cutaneous adaptation to water balance. The behaviour of such anuran species, together with their physiological characteristics, should be the main tools to face the challenge of living in xeric conditions. [ABSTRACT FROM AUTHOR]

Excavation of burrows is an extremely physically demanding activity producing a large amount of metabolic heat. Dissipation of its surplus is crucial to avoid the risk of overheating, but in subterranean mammals it is complicated due to the absence of notable body extremities and high humidity in their burrows. IR-thermography in a previous study on two species of African mole-rats revealed that body heat was dissipated mainly through the ventral body part, which is notably less furred. Here, we analyzed the dorsal and ventral skin morphology, to test if dermal characteristics could contribute to higher heat dissipation through the ventral body part. The thickness of the epidermis and dermis and the presence, extent and connectivity of fat tissue in the dermis were examined using routine histological methods, while vascular density was evaluated using fluorescent dye and confocal microscopy in the giant mole-rat Fukomys mechowii. As in other hitherto studied subterranean mammals, no subcutaneous adipose tissue was found. All examined skin characteristics were very similar for both dorsal and ventral regions: relative content of adipose tissue in the dermis (14.4 ± 3.7% dorsally and 11.0 ± 4.0% ventrally), connectivity of dermal fat (98.5 ± 2.8% and 95.5 ± 6.8%), vascular density (26.5 ± 3.3% and 22.7 ± 2.3%). Absence of large differences in measured characteristics between particular body regions indicates that the thermal windows are determined mainly by the pelage characteristics. [ABSTRACT FROM AUTHOR]

The goal was to prove by complex morphological analysis the purposefulness of using a biocomposition based on silver nanoparticles stabilized in solution with sodium alginate and the inhibitor of proteases of aprotinin for influencing the course of the inflammatory process after thermal burn. Using light and electron microscopy we studied morphological changes after thermal skin damage of II grade in rats using biocomposite based on silver nanoparticles stabilized in solution with sodium alginate and the protease inhibitor aprotinin to modify the course of the inflammatory process. Research was performed on 80 white male Wistar rats, 180-200g weight. The early wound process (3rd day) did not differ in various groups and was characterized by the predominance of exudative-necrotic and dyscirculatory disorders over the regeneration processes. From the 7th day, the morphological picture began to differ depending on the applied medication therapy. There was noted the beginning of rejection of the scab, a decrease in the intensity of inflammation, in hemodynamic disturbances and the onset of epithelialization. On the 14th day, the epithelialization was observed, the inflammatory process was decreasing and the young scar was forming. The use of erythromycin facilitated the migration of keratinocytes and accelerated the restoring of connective tissue in dermis through synthetic activity of fibroblasts. The use of the silver nanoparticle composition had a moderate corrective effect. After proteinase inhibitors application, the dystrophic changes, both in the epidermis and in dermis, persisted longer than in other groups. At the same time, samples where burns were treated by combined way (the solution of nano-silver and an inhibitor of proteases of aprotinin) demonstrated morphological signs of the increase in the keratinocytes proliferative activity and functional activation of protein synthesis of fibroblasts. According to the results of light and electron microscopy, the best result was obtained after combined therapy; the morphological characteristic of wounds was somewhat worse after antibiotic or silver monotherapy. The monotherapy only with the proteinase inhibitor gave the worst results on the duration of healing and the severity of inflammation in the wound. The local application of the silver nanoparticles stabilized in sodium alginate solution and aprotinin limited the destructive changes in the burnt skin, assisted in early repair processes, helped in the formation of granulation tissue, its maturation and epithelization. [ABSTRACT FROM AUTHOR]

Amphibian skin is highly variable in structure and function across anurans, and plays an important role in physiological homeostasis and immune defence. For example, skin sloughing has been shown to reduce pathogen loads on the skin, such as the lethal fungus Batrachochytrium dendrobatidis (Bd), but interspecific variation in sloughing frequency is largely unknown. Using phylogenetic linear mixedmodels, we assessed the relationship between skin turnover rate, skin morphology, ecological traits and overall evidence of Bd-driven declines. We examined skin sloughing rates in 21 frog species from three continents, as well as structural skin characteristics measured from preserved specimens. We found that sloughing rate varies significantly with phylogenetic group, but was not associated with evidence of Bd-driven declines, or other skin characteristics examined. This is the first comparison of sloughing rate across a wide range of amphibian species, and creates the first database of amphibian sloughing behaviour. Given the strong phylogenetic signal observed in sloughing rate, approximate sloughing rates of related species may be predicted based on phylogenetic position. While not related to available evidence of declines, understanding variation in sloughing rate may help explain differences in the severity of infection in genera with relatively slow skin turnover rates (e.g. Atelopus). [ABSTRACT FROM AUTHOR]

Nonylphenol ethoxylates (NPEs) are well known endocrine disruptors. Widespread environmental contamination from NPEs is an issue of great concern. Despite amphibians are often exposed to such contaminants, very little attention has been dedicated to this vertebrate group. No information is available on the effects of NPEs onto the amphibian skin and only few reports have been conducted on fish. Here, histological and ultrastructural modifications of the skin have been evaluated in the Italian newt Lissotriton italicus . After a short-term exposure to two ecologically relevant concentrations of NP, severe pathological alterations, both dose and time-dependent, have been observed. The main effects were an increased mucous secretion, the dilation of the endomembrane, the wrinkling of the epidermal surface, the appearance of tubercles, the increased cellular turnover, continuous shedding processes. Some of the described skin alterations can easily interfere with physiological functions, such as osmoregulation and body protection, with detrimental consequences for the amphibian populations. [ABSTRACT FROM AUTHOR]

Skin can respond to various types of internal and/or external mechanostimuli, such as excessive tension caused by body growth or decompression due to weight loss, which significantly affect skin morphology. Mechanosensors, including p130Cas, are reported to play a role in deformation and subsequent recovery of various tissues including skeletal muscles and blood vessels. However, the role of mechanotransduction via p130Cas in the regulation of skin size remains unclear. In this report, p130Cas activation was manipulated using a fibroblast-embedded collagen gel model or mouse skin contraction model. Inhibition or activation of Src family kinase-mediated phosphorylation of p130Cas significantly depressed and accelerated collagen gel contraction, respectively. The results also demonstrated age-dependent depression of cutaneous p130Cas activation in vivo. Inhibition of p130Cas signaling in our mouse model significantly suppressed recovery from cutaneous deformation. Taken together, our study highlighted the important role of p130Cas in cutaneous mechanotransduction for skin homeostasis. [ABSTRACT FROM AUTHOR]

Glyphosate-based herbicides are widely used in agriculture and are commonly found in water bodies. Roundup Original ® (RO) contains an isopropylamine glyphosate (GLY) salt containing the surfactant POEA, while Roundup Transorb R ® (RTR) contains a potassium salt of GLY with unknown surfactants. Both contain different compositions of so-called “inert” ingredients, more toxic than glyphosate. Amphibian tadpoles often experience variations in O 2 availability in their aquatic habitats; an ability to tolerate hypoxia can condition their survival and fitness. We evaluated the impacts of sublethal concentrations of GLY (1 mg L −1 ), RO (1 mg L −1 GLY a.e) and RTR (1 mg L −1 GLY a.e) on metabolic rate ( V · O 2 – mLO 2 Kg1 h −1 ) of bullfrog tadpoles during normoxia and graded hypoxia, and related this to morphology of their skin, their major site of gas exchange. In control (CT) V · O 2 remained unaltered from normoxia until 40 mmHg, indicating a critical O 2 tension between 40 and 20 mmHg. GLY significantly reduced V · O 2 , possibly due to epidermal hypertrophy, which increased O 2 diffusion distance to O 2 uptake. In contrast, RTR increased V · O 2 during hypoxia, indicating an influence of “inert” compounds and surfactants. V · O 2 of RO did not differ from CT, suggesting that any increase in V · O 2 caused by exposure was antagonized by epidermal hypertrophy. Indeed, all herbicides caused marked alterations in skin morphology, with cell and epithelium wall presenting hyperplasia or hypertrophy and chromatid rupture. In summary, GLY, RO and RTR exert different effects in bullfrog tadpoles, in particular the surfactants and inert compounds appear to influence oxygen uptake. [ABSTRACT FROM AUTHOR]

Background: Most traditional skin histological analysis methods are based on the light microscopy images, which can only provide limited information and low contrast results for pathology evaluation. Molecular hyperspectral imaging technology can provide both spatial and spectral information of skin sections, which is a new method for histological skin analysis. Methods: The molecular hyperspectral imaging system was developed by coupling an acousto-optic tunable filters adapter to microscopy and the molecular hyperspectral images were analyzed by home-written software with image processing algorithms. Then, the histological structures in skin sections were investigated in several locations to evaluate the potential application of the molecular hyperspectral imaging technique to dermatology. Results: Molecular hyperspectral images of skin sections were obtained. Single-band images, false color images, virtual 3D surface view images, and color-coded spectral clustering results were produced to highlight the skin structures for histological evaluation. Conclusion: Unlike traditional histological analysis with light microscopy, the molecular hyperspectral imaging technology can enhance the visualization of skin structures using their spectral signatures and their gray values. This technology has potential for the diagnosis and histopathologic characterization of different kind of skin cells. [ABSTRACT FROM AUTHOR]

Abstract: The posterior aspect of heel is known as a particularly vulnerable site for pressure ulcer development, however, it is not well understood why this is so. This study was undertaken to identify the morphological characteristics of the skin over posterior aspect of heel in the context of pressure ulcer development. Human skin tissues were obtained from four different sites of the body of 4 aged subjects postmortem: posterior aspect of heel, plantar aspect of heel, sacrum and centre of gluteus maximus. The skin samples were processed for the examination using light microscopy and scanning electron microscopy. The posterior aspect of heel was characterized by a thicker epidermis, denser distribution and larger diameter of capillaries in the papillary layer, 3-dimensional architecture of collagen fibre meshwork in the reticular layer and elliptic adipose tissues situated perpendicularly to the skin surface being surrounded by thick collagen and elastic fibre septa compared to the sacrum. Given our observations in the papillary layer of the posterior aspect of heel, we assume that the tissue of this area may be less tolerant to ischaemia since the tissue has high metabolic demand to provide oxygen and nutrients to the epidermis which protects underlying tissue from external force. In addition, elliptic configuration of adipose tissues in the posterior aspect of heel situated perpendicularly to the skin surface may result in deep lesion if the forces applied exceed the tolerable level since the forces will be concentrated within the elliptic compartments. [Copyright &y& Elsevier]

Abstract: The changes and biochemical features of the epidermis that accompany the differentiation and embryonic shedding complex formation in grass snake Natrix natrix L. embryos were studied ultrastructurally and immunocytochemically with two panels of antibodies (AE1, AE3, AE1/AE3; anti-cytokeratin, pan mixture, Lu-5 and PCK-26). All observed changes in the ultrastructure of the cells forming the epidermal layers were associated with the physiological changes that occurred in the embryonic epidermis, such as changing of the manner of nutrition and keratinization leading to the embryonic shedding complex formation. The layers that originated first (basal, outer and inner periderm and clear layer) differentiated very early and rapidly. Rapid differentiation was also observed in the layers that are very important for the functioning of the epidermis in Natrix embryos (oberhäutchen and beta-layers). They started to differentiate at developmental stage IX, and then fused and formed the embryonic shedding complex at developmental stage XI. During the embryonic development of the grass snake the smallest changes appeared in the ultrastructure of the cells in the mesos and alpha-layers because they perform supplementary functions in the process of embryonic molting. They were undifferentiated until the end of embryonic development and started to differentiate just before the first adult molting. AE1/AE3, anti-cytokeratin, pan mixture, Lu-5 and PCK-26 antibodies immunolabeled clear layer, oberhäutchen and beta-layers at the latest phase of developmental stage XI. It should be noted that these antibodies did not immunolabel the alpha-layer until hatching. The presence of alpha-keratin immunolabeling in layers that were keratinized, particularly in the oberhäutchen and beta-layers in embryos, indicated that they were not as hard as in fully mature individuals. [ABSTRACT FROM AUTHOR]

Recently, there has been an increase in the number of people who experience skin problems including atopic dermatitis. This situation has led to a high demand for clothing with minimal irritation to the skin. Here we conducted a survey to observe the self-awareness of the current situation of female college student's body skin by written questionnaire. The result was distributed by the normal skin 44.9%, the unstable skin 8.7%, the sensitive skin 24.6% and the highly sensitive skin (including the disordered skin) 2 1.8%, and it showed that about 60% people realize their body skin problems. Then the appearance of different types of skin was quantitatively compared and analyzed from the physiological and morphological points of view. Based on the self-diagnosis results collected through the survey, the selected study group,comprised of twelve young women (20-23 years old) was divided by skin type; 7 with normal skin and 5 with highly sensitive skin. Each skin type was examined for transepidermal water loss (TEWL) as a physiological observation, perspiration rate to monitor the status of sweating and skin surface roughness by profilometry as a morphological analysis, in specific regions of the upper body. The physiological characteristics revealed that the highly sensitive skin had a higher value of TEWL and a significantly lower value in the perspiration rate compared to the normal skin type. The measurement of the morphological characteristics showed that the skin roughness of the highly sensitive skin had a higher value than that of the normal skin. These results reveal the differences between the two skin types and suggest the need for special consideration in designing clothing for sensitive skin. [ABSTRACT FROM AUTHOR]

The replicating technique of skin integument which is an effective tool to observe the skin's surface characteristics is widely implemented in the cosmetic field. In this study, considering the effects to the skin caused by wearing clothing, such as friction and pressure, the replicating technique was applied to evaluate the skin surface of the trunk and limbs in the viewpoint of skin morphology. As preliminary data, the skin surface contour was observed through optical profilometry in three dimensions. The subjects were comprised of seven young women with the normal skin. Six regions of upper body were replicated by silicone rubber to measure the surface contour. There were two measuring environments, i.e., neutral condition at 27°C, and sweating condition at 32°C with a footbath. The measurements were repeated twice in each person. The results showed a significant difference in the surface contour among replicated regions. This fact suggested that sweating decreases skin surface roughness in the vertical direction significantly. These results reveal that this method is appropriate to relatively describe the skin surface contour quantitatively. [ABSTRACT FROM AUTHOR]

Abstract: This study focused on the in vitro evaluation of skin perforation using a new microneedle device (Dermaroller®) with different needle lengths (150, 500 and 1500μm). The influence of the microneedle treatment on the morphology of the skin surface (studied by light and scanning electron microscopy), on the transepidermal water loss (TEWL) and on the penetration and permeation of hydrophilic model drugs was investigated using excised human full-thickness skin. Furthermore, invasomes – highly flexible phospholipid vesicles containing terpenes and ethanol as penetration enhancer – were compared with an aqueous solution. Elevated TEWL values were measured after Dermaroller® treatment compared to untreated human skin with a gradual increase of the TEWL over the first hour whereas afterwards the TEWL values decreased probably caused by a reduction of the pore size with time. Skin perforation with the Dermarollers® enhanced drug penetration and permeation for both formulations tested. Invasomes were more effective to deliver hydrophilic compounds into and through the skin compared to the aqueous drug solutions and the combination with skin perforation further enhanced drug penetration and permeation. In conclusion, Dermarollers® being already commercially available for cosmetic purposes appear also promising for drug delivery purposes particularly those with medium (500μm) and shorter (150μm) needle lengths. [Copyright &y& Elsevier]

Optical coherence tomography (OCT) appears to be a promising technique to study skin in vivo. As part of an exploratory study to investigate UV induced effects non-invasively we aimed to evaluate the kinetics of acute UVB- as well as UVA1 induced skin alterations by means of OCT, and to correlate the results obtained with routine histology. Twelve healthy subjects received daily 60 J/cm2 of UVA1 and 1.5 minimal erythema doses of UVB on their upper back over three consecutive days. One day (24 h) after the last UV exposure, OCT measurements and skin biopsies were performed in four subjects (day 1) on the centre of the irradiated sites and an adjacent non-irradiated control site. The same procedure was performed in four subjects 3 days and 6 days after irradiation, respectively. Prior to OCT assessment two waterproof marks were drawn on the centre of UVB and UVA1 exposed sites and the control site. The OCT scanner, SkinDex 300, was used in the RI1D measurement modus in order to investigate morphological features, epidermal thickness, and scattering coefficients. Immediately after OCT assessment, 4 mm punch biopsies were taken from the previously marked sites. OCT as well as histological examinations performed on day 1, 3, and 6, revealed markedly higher values for epidermal thickness on UVB exposed skin sites, and slightly increased epidermal thickening in UVA1 exposed sites. UVB exposed sites showed disruption of the entrance signal in the B-scan of OCT resulting in a thickened layer with a signal-poor centre corresponding to hyperkeratosis and parakeratosis as confirmed by routine histology. Surprisingly, the mean scattering coefficients of the epidermis were slightly lower on UVA1 exposed sites, as compared to non-irradiated skin. By contrast, the scattering coefficient of the upper dermis of UVA1 irradiated skin was hardly altered. Moreover, the scattering coefficient of the upper dermis assessed on UVB exposed skin on day 1 was clearly smaller than the scattering coefficient observed on non-irradiated and UVA1 exposed skin. Conclusively, it was possible to demonstrate by means of OCT differences of epidermal thickness and pathological features of the stratum corneum following UV exposure. UVA1 induced epidermal pigmentation as well as UVB induced dermal inflammation may affect the light attenuation in the tissue indicated by a decrease of the scattering coefficient. OCT seems to be a useful tool to monitor UV induced effects in vivo. [ABSTRACT FROM AUTHOR]

eSS rats exhibit a non-insulin-dependent diabetic syndrome, significantly influenced by diet. Long-term effects of intermittent dietary restriction were studied in male eSS rats. Experimental animals were fed ad libitum during 48h and food-deprived the next 24h (R) while controls (L) of the same strain were freely fed every day. This schedule was maintained from 21 days of age until all rats were sacrificed. R animals were leaner than L rats at 5, 8 and 13 months of age. Moreover, an improved metabolic profile (i.e., lower levels in blood triglycerides, total blood cholesterol, basal blood glucose and blood glucose after an oral glucose load) was found. Histological examination of nuchal skin specimens showed a significant increase of dermal thickness and epidermal hypotrophy in free-fed animals. Collagenous fibers closely packed were found just beneath the dermo-epidermal junction in L rats. This finding was less pronounced in R rats. The above mentioned results suggest that eSS rats would draw advantage from living in environments where food availability is uncertain. The importance of early dietary restrictions in predisposed genotypes appears to be a valuable preventive measure against diabetic evolution and complications. [ABSTRACT FROM AUTHOR]

The glabrous skin around the nostrils in mammals is called a rhinarium or planum nasale. Rhinarium skin has multiple epidermal domes that are generally assumed to form a tactile surface. The rhinarium is innervated by a branch of the trigeminal nerve which is associated with stimuli such as touch, chemical irritants and temperature. In this study, our aim was to correlate variation in rhinarium skin sensory innervation with different feeding behaviors while also covering a broad systematic spectrum. Using histological and immunohistological methods, we studied skin morphology, nerve fiber density and nerve fiber distribution in the rhinarium epidermal domes of four species: cow, ring-tailed lemur, brown bear, and dog, that all exhibit different feeding behaviors. All species share similar traits in rhinarium skin morphology, but glands were only found in cow rhinarium skin. The most substantial differences were observed in the innervation pattern. Mechanosensory skin organs were found only in the ring-tailed lemur. Dog epidermal domes possess a pronounced central dermal papilla containing a nerve bundle in its top, close to the skin surface. The abundance of free epidermal nerve fibers in epidermal domes of all species, suggest that the rhinarium skin is a sensory surface, that can be used to detect fine touch, chemical irritants or temperature. In the species where the whole epidermal dome was examined, the intraepidermal nerve fiber density is higher in the central part of the domes. The nerve distribution and the central positioning of a single gland duct in cow and the dermal papilla top organ in dog indicates that each epidermal dome can be considered a functional unit. The observed differences in innervation hint at different sensory functions of rhinaria in mammals that may be correlated to feeding behavior., (© 2021 The Authors. Journal of Morphology published by Wiley Periodicals LLC.)