The structure and function of muskox preorbital glands

1989 ◽  
Vol 67 (5) ◽  
pp. 1134-1142 ◽  
Author(s):  
David R. Gray ◽  
Peter F. Flood ◽  
Janice E. Rowell
Keyword(s):  
Scent Marking ◽  
Hair Follicles ◽  
Behaviour Pattern ◽  
Sweat Glands ◽  
Play Fighting ◽  
The Face ◽  
In The Wild ◽  
Lacrimal Bone ◽  
Marking Behaviour ◽  
And Function

The preorbital gland of the muskox is a relatively large pear-shaped structure lying rostral to the eye between the skin and the lacrimal bone. It surrounds a narrow tubular invagination of the skin, which conveys the largely aqueous secretion to the surface of the face. This tube, which enters the gland at its rostrolateral extremity and runs caudodorsally, is partially filled with stiff hairs that arise from follicles in its wall. Most of the gland consists of tightly packed apocrine sweat glands, but large sebaceous glands are associated with the hair follicles of the central tube. The myoepithelium of the sweat glands is highly developed but the facial muscles overlying the gland are very thin and probably do not contribute significantly to the expulsion of secretion. Secretion is mechanically expressed when the animal rubs the area of the gland on something firm such as its own foreleg (gland rubbing) or a prominent object in the environment (rubbing). The gland is functional in both sexes throughout the year but is much larger in males. In the wild, scent marking and gland rubbing occur during aggressive encounters between individuals within a herd, between herds, and between muskoxen and other species. Gland rubbing in females and subadults is usually restricted to interspecific encounters but in males it occurs in most intense agonistic situations. Wild calves performed the self-marking behaviour as early as 1 week of age when play fighting. Captive muskoxen did not rub their preorbital gland on the foreleg but commonly rubbed it on objects. The authors believe that the principal function of the preorbital gland is to provide an olfactory component of the threat behaviour pattern.

Behavioural context and possible function of scent marking by cheek rubbing in the red squirrel (Tamiasciurus hudsonicus)

1989 ◽  
Vol 67 (7) ◽  
pp. 1650-1653 ◽  
Author(s):  
Jean Ferron ◽  
Jean-Pierre Ouellet
Keyword(s):  
Relative Frequency ◽  
Scent Marking ◽  
Contextual Analysis ◽  
Tamiasciurus Hudsonicus ◽  
Behaviour Pattern ◽  
Adult Males ◽  
Resting Sites ◽  
In Captivity ◽  
In The Wild ◽  
Marking Behaviour

A contextual analysis of scent marking by cheek rubbing in wild red squirrels (Tamiasciurus hudsonicus), based on the study of behavioural time budgets and sequences, is presented. Scent-marking rates do not differ significantly between adult males and females. Comparison of the relative frequency of occurrence of each behaviour pattern in a scent-marking context with the relative frequency of these patterns in all other contexts reveals that locomotion, alertness, grooming, food carrying, and gnawing have a higher probability of occurrence when there is cheek rubbing. These results concur with earlier findings in captivity. Contextual analysis in the wild clearly indicates low association of cheek rubbing with social context and greater use of this behaviour at grooming and resting sites and along the path used by the marking animal. This suggests that cheek rubbing is mainly self-oriented to maintain the animal's familiarity with its home range. This scent-marking behaviour may also be used to advertise occupancy of a given territory to conspecifics.

The development, structure, and function of the submandibular cutaneous (chin) glands in the rabbit.

1964 ◽  
Vol 12 (3) ◽  
pp. 340 ◽  
Author(s):  
AG Lyne ◽  
GS Molyneux ◽  
R Mykytowycz ◽  
PF Parakkal
Keyword(s):  
Oryctolagus Cuniculus ◽  
Osmium Tetroxide ◽  
Structure And Function ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Secretory Cells ◽  
Adult Males ◽  
Dark Cells ◽  
And Function ◽  
Development Structure

Embryological, histological, and histochemical features of the chin glands in the rabbit, Oryctolagus cuniculus (L.), are described. The glands are modified sweat glands which develop as appendages of the first hair follicles of the pelage. All the secretory cells are of the merocrine type, although some secrete in the typical apocrine manner. In the adult, the glands are much better developed in males than in females. Two main types of secretory cells were clearly seen in most animals, particularly adult males. Cells which stained heavily with osmium tetroxide (dark cells) were also present. No other mammalian cutaneous gland is so complex. Histochemical techniques to demonstrate enzymes revealed that particular glandular components contained large amounts of alkaline phosphatase and the whole gland was well supplied with nerves containing cholinesterases. The function of the secretion from these glands in marking territories is outlined.

Structure and function of the skin

2020 ◽  
pp. 3-14
Keyword(s):  
Barrier Function ◽  
Individual Cell ◽  
Normal Skin ◽  
Cell Types ◽  
Structure And Function ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Dermoepidermal Junction ◽  
The Individual ◽  
And Function

The structure and function of the skin details the individual components of the epidermis, dermis, and their roles in normal skin health. The individual cell types in the epidermis, the different epidermal layers, and the roles of the keratinocyte are explained. The epidermis and dermis, and their important relation to each other through the dermoepidermal junction are described. The dermal adnexal structures of hair follicles (pilosebaceous units), sweat glands, and nerves are all considered. The functions of skin and barrier function are also listed. Rare but important causes of disordered sweating (hyperhidrosis and hypohidrosis) are described. In addition, presentations of hyperhidrosis are discussed.

scholarly journals Generation of Skin Organoids: Potential Opportunities and Challenges

2021 ◽  
Vol 9 ◽  
Author(s):  
Hui Sun ◽  
Yi-Xuan Zhang ◽  
Yu-Mei Li
Keyword(s):  
Human Skin ◽  
Skin Diseases ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Generation Model ◽  
Skin Substitutes ◽  
Local Skin ◽  
Cell Microenvironment ◽  
And Function

Although several types of human skin substitutes are currently available, they usually do not include important skin appendages such as hair follicles and sweat glands, or various skin-related cells, such as dermal adipocytes and sensory neurons. This highlights the need to improve the in vitro human skin generation model for use as a tool for investigating skin diseases and as a source of cells or tissues for skin regeneration. Skin organoids are generated from stem cells and are expected to possess the complexity and function of natural skin. Here, we summarize the current literatures relating to the “niches” of the local skin stem cell microenvironment and the formation of skin organoids, and then discuss the opportunities and challenges associated with multifunctional skin organoids.

The regional anatomy of the human integument with special reference to the distribution of hair follicles, sweat glands and melanocytes

1967 ◽  
Vol 252 (779) ◽  
pp. 447-485 ◽  
Keyword(s):  
Regional Variation ◽  
Regional Differences ◽  
Basal Layer ◽  
Skin Surface ◽  
Absolute Number ◽  
Hair Follicles ◽  
The Body ◽  
Sweat Glands ◽  
Significant Difference ◽  
The Face

The regional anatomy of human skin is discussed in terms of ( a ) the regional variation of the architectural pattern of the basal layer of the epidermis, ( b ) the regional variation in the distribution of hair follicles and eccrine sweat glands, and the regional variation in the distribution of melanocytes. ( a ) The architecture of the basal layer is regionally specific. The epidermis of the cheek is almost flat between the numerous hair follicles. Regions under tension have parallel ridges that end abruptly (neck, breast, abdomen); regions with a thick keratin or mucous layer have deep ridges with circular imprints of tall dermal papillae (sole, palm, knee, heel and oral mucosa). Elsewhere in the epidermis the creases of the skin surface divide the pattern of the basal layer into diamond-shaped areas where the imprints of the dermal papillae are to be seen. ( b ) There is great individual and regional variation in the distribution of hair follicles and sweat ducts:700 + 40 hair follicles per cm 2 were counted on the face, but only 65 + 5 in the rest of the body. The corresponding density for eccrine sweat glands was 270 + 25 in the face and 160 + 15 in the rest of the body. There are altogether about two million hair follicles and three million sweat glands in the integument. The epidermal appendages are symmetrically distributed; there is no significant difference between male and female in the density of hairs or sweat glands. The density of appendages is much higher in the foetus and in the infant than in the adult. Numerical estimates have shown that the differential rate of growth of the body surface may be solely responsible for regional differences in the density of appendages. A uniformly distributed foetal population of appendages would become ‘diluted’ three times more on the trunk and extremities than on the head during postnatal growth. The numerical ratio of sweat ducts/hair follicles is the same throughout foetal and postnatal life. ( c ) On the average there are about 1500 epidermal melanocytes/mm 2 of skin surface, excluding those in hair follicles. The total number of epidermal melanocytes in an adult is about 2000 million. They occur consistently in the basal layer of the epidermis of ‘white’ human skin (including the oral and nasal cavities). Their absolute number and their proportion to the keratinizing basal Malpighian cells are constant and characteristic in given regions. The distribution of melanocytes is also bilaterally symmetrical and their regional frequency is the same in male and female. The individual and regional variations of melanocyte distribution are, however, great. There are two or three times as many melanocytes per unit area in the epidermis of the cheek or forehead as in the other regions of the integument. Because melanocytes are mostly located on ridges, the numerical ratio of Malpighian cells/melanocytes is lower on than between the ridges. The cause of the great regional variation of melanocytes is not known. The regional differences are smaller in foetal than in adult skin. Regional differences in the degree of expansion of the body surface by growth cannot, however, explain the regional variation in the adult. Melanocyte density in the foetus is lower than in the adult, and in old epidermis a decrease in melanocyte density is one of the manifestations of ageing. Comparisons of the frequency distribution of melanocytes reveal no significant difference between the various human races. The degree of melanization of skin therefore depends not only on the number of melanocytes, but, more particularly, on their physiological activity in melanogenesis. The absolute number of melanocytes and the ratio of Malpighian cells/melanocytes are high enough to allow melanocytes to make contact with every Malpighian cell and so to disseminate melanin through the entire basal layer of the epidermis.

scholarly journals Hybrid Attention Cascade Network for Facial Expression Recognition

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2003 ◽  
Author(s):  
Xiaoliang Zhu ◽  
Shihao Ye ◽  
Liang Zhao ◽  
Zhicheng Dai
Keyword(s):  
Facial Expression ◽  
Facial Expressions ◽  
Facial Expression Recognition ◽  
Expression Recognition ◽  
Spatial Features ◽  
Face Images ◽  
Temporal Features ◽  
The Face ◽  
In The Wild ◽  
Fusion Features

As a sub-challenge of EmotiW (the Emotion Recognition in the Wild challenge), how to improve performance on the AFEW (Acted Facial Expressions in the wild) dataset is a popular benchmark for emotion recognition tasks with various constraints, including uneven illumination, head deflection, and facial posture. In this paper, we propose a convenient facial expression recognition cascade network comprising spatial feature extraction, hybrid attention, and temporal feature extraction. First, in a video sequence, faces in each frame are detected, and the corresponding face ROI (range of interest) is extracted to obtain the face images. Then, the face images in each frame are aligned based on the position information of the facial feature points in the images. Second, the aligned face images are input to the residual neural network to extract the spatial features of facial expressions corresponding to the face images. The spatial features are input to the hybrid attention module to obtain the fusion features of facial expressions. Finally, the fusion features are input in the gate control loop unit to extract the temporal features of facial expressions. The temporal features are input to the fully connected layer to classify and recognize facial expressions. Experiments using the CK+ (the extended Cohn Kanade), Oulu-CASIA (Institute of Automation, Chinese Academy of Sciences) and AFEW datasets obtained recognition accuracy rates of 98.46%, 87.31%, and 53.44%, respectively. This demonstrated that the proposed method achieves not only competitive performance comparable to state-of-the-art methods but also greater than 2% performance improvement on the AFEW dataset, proving the significant outperformance of facial expression recognition in the natural environment.

Methods of scent marking in the domestic cat

1994 ◽  
Vol 72 (6) ◽  
pp. 1093-1099 ◽  
Author(s):  
Hilary N. Feldman
Keyword(s):  
Home Range ◽  
Scent Marking ◽  
Domestic Cat ◽  
Tree Bark ◽  
Scent Mark ◽  
Adult Males ◽  
Felis Silvestris ◽  
Felis Silvestris Catus ◽  
The Face ◽  
Visual Mark

Carnivores use various scent-marking methods. Semi-feral domestic cats (Felis silvestris catus) were observed to use the same means as their wild counterparts. Adult males performed most urine spray marking. Cats scratched tree bark, producing a visual mark, and probably used trees both as markers and for claw sharpening. Most scratching trees were located along frequently used paths rather than along territorial boundaries or scattered randomly throughout a home range. Bark consistency affected the tree species that were scratched, with soft bark preferred. Although deposition of faeces and urine was recorded, there was no clear evidence for their use as territorial markers; cats primarily eliminated away from the core area of the home range. Most faeces were buried, although exposed deposits were also observed. Cats also rubbed against objects, probably using glandular secretions from the face and tail areas to scent mark. Males rubbed objects more than females, and males scent marked more. Individual males may use different means of scent marking. Scent marking in this study supports the idea that cats do not defend territories, instead patrolling and reinforcing marks throughout a looser home range. The suggestion has been made that different forms of marking may serve separate signalling functions.

Regulation of hair follicle development by the TNF signal ectodysplasin and its receptor Edar

Development ◽  
2002 ◽  
Vol 129 (10) ◽  
pp. 2541-2553 ◽  
Author(s):  
Johanna Laurikkala ◽  
Johanna Pispa ◽  
Han-Sung Jung ◽  
Pekka Nieminen ◽  
Marja Mikkola ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Hair Follicles ◽  
Wild Type ◽  
Mutant Mouse Embryos ◽  
Anhidrotic Ectodermal Dysplasia ◽  
Embryonic Morphogenesis ◽  
Hair Follicle Development ◽  
And Function ◽  
Insight Into

X-linked and autosomal forms of anhidrotic ectodermal dysplasia syndromes (HED) are characterized by deficient development of several ectodermal organs, including hair, teeth and exocrine glands. The recent cloning of the genes that underlie these syndromes, ectodysplasin (ED1) and the ectodysplasin A receptor (EDAR), and their identification as a novel TNF ligand-receptor pair suggested a role for TNF signaling in embryonic morphogenesis. In the mouse, the genes of the spontaneous mutations Tabby (Ta) and downless (dl) were identified as homologs of ED1 and EDAR, respectively. To gain insight into the function of this signaling pathway in development of skin and hair follicles, we analyzed the expression and regulation of Eda and Edar in wild type as well as Tabby and Lef1 mutant mouse embryos. We show that Eda and Edar expression is confined to the ectoderm and occurs in a pattern that suggests a role of ectodysplasin/Edar signaling in the interactions between the ectodermal compartments and the formation and function of hair placodes. By using skin explant cultures, we further show that this signaling pathway is intimately associated with interactions between the epithelial and mesenchymal tissues. We also find that Ta mutants lack completely the placodes of the first developing tylotrich hairs, and that they do not show patterned expression of placodal genes, including Bmp4, Lef1, Shh, Ptch and Edar, and the genes for β-catenin and activin A. Finally, we identified activin as a mesenchymal signal that stimulates Edar expression and WNT as a signal that induces Eda expression, suggesting a hierarchy of distinct signaling pathways in the development of skin and hair follicles. In conclusion, we suggest that Eda and Edar are associated with the onset of ectodermal patterning and that ectodysplasin/edar signaling also regulates the morphogenesis of hair follicles.

scholarly journals The Sweat Glands and Hair Follicles of European Cattle

1972 ◽  
Vol 25 (3) ◽  
pp. 585 ◽  
Author(s):  
D Mcewan Jenkinson ◽  
T Nay
Keyword(s):  
Hair Follicle ◽  
Sweat Gland ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Mean Values ◽  
The Mean ◽  
European Cattle

Measurements were made on the skins of 1363 cattle from different European breeds. The mean values of these measurements have been tabulated for each breed and the skin types present in each breed or group of breeds have been determined using sweat gland shape (LID) and hair follicle depth (FrY) as the principal bases of comparison.

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