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.

scholarly journals Relationship Between Cyclic Changes in the Hair Follicle and Sweat Gland Size in Cattle

1966 ◽  
Vol 19 (4) ◽  
pp. 607 ◽  
Author(s):  
AV Schleger
Keyword(s):  
Hair Follicle ◽  
Sweat Gland ◽  
Hair Growth ◽  
Hair Follicles ◽  
Diameter Ratio ◽  
Sweat Glands ◽  
Growth Phases ◽  
Gland Size ◽  
The Mean ◽  
Cyclic Changes

The morphology of hair follicles has been studied in 23 Africander-Hereford crossbred yearlings. Eleven hair growth phases were recognized as a result of work on two animals. The piloapocrine units representing each phase have been illustrated by tracings. The mean length, diameter, length-diameter ratio, and area of sweat glands corresponding to each phase have been tabulated and illustrated.

scholarly journals The Sweat Glands and Hair Follicles of Asian, African, and South American Cattle

1973 ◽  
Vol 26 (1) ◽  
pp. 259 ◽  
Author(s):  
D Mcewan jenkinson ◽  
T Nay
Keyword(s):  
Sweat Gland ◽  
Hair Follicles ◽  
Sweat Glands ◽  
South American ◽  
Mean Values ◽  
The Mean

Measurements were made on the skins of 471 Asian, 281 African, and 186 South American cattle from different breeds, and the mean values have been tabulated. The skin types present in each breed or group of breeds were determined using sweat gland shape (LID), i.e.

Skin structure of Egyptian buffaloes and cattle with particular reference to sweat glands

1955 ◽  
Vol 46 (1) ◽  
pp. 19-30 ◽  
Author(s):  
E. S. E. Hafez ◽  
A. L. Badreldin ◽  
M. M. Shafei
Keyword(s):  
Hair Follicle ◽  
Sweat Gland ◽  
Species Differences ◽  
Hair Follicles ◽  
The Body ◽  
Sweat Glands ◽  
Average Thickness ◽  
Sebaceous Glands ◽  
Body Regions ◽  
Dermal Papillae

The structure, distribution and dimensions of skin strata and sweat glands have been investigated in Egyptian buffaloes and cattle. Samples from sixteen body regions were taken from three adult bulls of both species. Identical studies were also made on one buffalo calf and two buffalo embryos. Serial vertical and horizontal sections were cut from each body region using the ‘terpineol paraffin wax’ method. The following results were obtained.1. Buffalo skin is characterized by dermal papillae enclosing papillomatous epidermis. The fibrous structure of the dermis is similar in both species. In buffaloes, the average thickness of skin, main epidermis, papillomatous epidermis, and cornium is 6·5 mm., 50, 115, and 11μ respectively. The epidermis coefficient is 12 for the main epidermis and 18 for the papillomatous epidermis. In cattle, the average thickness of skin, epidermis and cornium layer is 4·3 mm., 51 and 5 μ respectively, while the epidermis coefficient is 8.2. The average number of hair follicles per sq.cm. of skin is 394 in the buffalo and 2633 in cattle. Each hair follicle is accompanied by two large lobulated sebaceous glands in the buffalo, and one small bilobed gland in cattle.3. There is no species difference in the histology of the sweat glands. Each hair follicle is accompanied by one sweat gland in both species. In the buffalo, the body of the sweat gland is oval and convoluted, while the duct is twisted at its attachment to the body. In cattle, the body of the gland is elongated while the duct is straight. The number of sweat glands per sq.cm. of skin is 394 in the buffalo and 2633 in cattle. The dimensions of the sweat glands are larger in buffaloes than in cattle. The length, circumference and sweating surface of the gland is 0·58, 0·47, and 0·276 sq.mm. in the buffalo, and 0·47, 0·26, and 0·124 sq.mm. in cattle respectively. The glandular surface of sweat glands per sq.cm. of skin is 1·07 sq.cm. in the buffalo and 3·08 sq.cm. in cattle.4. The type of sweat gland secretion is apocrine in both species. In the buffalo, successive stages of apocrine secretion are observed, and the merocrinelike form is rare. In cattle, the merocrine-like form prevails and the other stages are very rare. The theory (Findlay & Yang, 1950) of intraluminal transformation, of secretory products from coarse granularity to fluid homogeneity is supported. The effect of locality on the type of sweating activity is stressed.5. There are species differences in the distribution of blood vessels and capillaries. In the subepidermal level, the arterial branches are more frequent and superficial in buffaloes than in cattle. Capillaries are found in the dermal papillae of buffalo skin. The capillary loops encircling the hair follicle are more frequent in cattle than in buffaloes. The blood capillaries supplying the sebaceous glands are more numerous in the buffalo than in cattle. The blood supply of sweat glands is poor in both species.6. There are age differences in the skin histology. The number of hair follicles per sq.cm. of skin in a 5-months-old embryo, calf at birth, and adult buffaloes is 10560, 1248 and 400 respectively. There are no skin glands in the 1-month and 5-months-old embryos. The sweat gland in the calf is small in size and similar in structure to that of the adult. Calves have fewer sweat glands than adults.7. The body conformation and the degree of pigmentation are affected by species, breed and locality.8. The secreting activity of the sweat glands may be affected by the locality.9. It seems that there are species differences in the mechanism of heat convection and radiation, insensible perspiration and sensible perspiration, due to histological differences.

scholarly journals A genetic basis of variation in eccrine sweat gland and hair follicle density

2015 ◽  
Vol 112 (32) ◽  
pp. 9932-9937 ◽  
Author(s):  
Yana G. Kamberov ◽  
Elinor K. Karlsson ◽  
Gerda L. Kamberova ◽  
Daniel E. Lieberman ◽  
Pardis C. Sabeti ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Genetic Regulation ◽  
Eccrine Sweat Gland ◽  
Hair Follicles ◽  
The Body ◽  
Chromosome 1 ◽  
Sweat Glands ◽  
Eccrine Gland ◽  
Eccrine Glands ◽  
Eccrine Sweat

Among the unique features of humans, one of the most salient is the ability to effectively cool the body during extreme prolonged activity through the evapotranspiration of water on the skin’s surface. The evolution of this novel physiological ability required a dramatic increase in the density and distribution of eccrine sweat glands relative to other mammals and a concomitant reduction of body hair cover. Elucidation of the genetic underpinnings for these adaptive changes is confounded by a lack of knowledge about how eccrine gland fate and density are specified during development. Moreover, although reciprocal changes in hair cover and eccrine gland density are required for efficient thermoregulation, it is unclear if these changes are linked by a common genetic regulation. To identify pathways controlling the relative patterning of eccrine glands and hair follicles, we exploited natural variation in the density of these organs between different strains of mice. Quantitative trait locus mapping identified a large region on mouse Chromosome 1 that controls both hair and eccrine gland densities. Differential and allelic expression analysis of the genes within this interval coupled with subsequent functional studies demonstrated that the level of En1 activity directs the relative numbers of eccrine glands and hair follicles. These findings implicate En1 as a newly identified and reciprocal determinant of hair follicle and eccrine gland density and identify a pathway that could have contributed to the evolution of the unique features of human skin.

In vivo effects of epidermal growth factor on epidermal pattern formation and hair follicle initiation in the marsupial bandicoot Isoodon macrourus

1997 ◽  
Vol 9 (5) ◽  
pp. 493 ◽  
Author(s):  
David L. Adelson ◽  
David E. Hollis ◽  
James C. Merchant ◽  
Bronwyn A. Kelley
Keyword(s):  
Growth Factor ◽  
Pattern Formation ◽  
Epidermal Growth Factor ◽  
Hair Follicle ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Epidermal Growth

The extrauterine development of marsupial pouch young (northern brown bandicoot Isoodon macrourus) has facilitated the study of the effects of murine epidermal growth factor (mEGF) on pattern formation in skin. Hair follicle initiation and development, which in the mouse would occur from about Days 13–14 of gestation onward, occurs postnatally. In the present study the effect in vivo of mEGF on developing skin corresponding to mouse gestational ages from Day 13 onward was examined. Subcutaneous injections of mEGF (0· 5, 1 ·0 and 2· 0 µg g-1 body weight) or equivalent volumes of saline (0· 9% w/w) were administered daily, before and during hair follicle initiation and development. Murine EGF inhibited the formation of hair follicles, hair follicle sweat glands, sebaceous glands and dermal papillae. The pattern of follicle initiation was perturbed. The characteristic trio follicle grouping was absent, and follicle rudiment densities (no. per mm2skin surface) were significantly lower in animals treated with mEGF, whereas follicle diameters were increased. These data may reflect a role for the epidermal growth factor (EGF) receptor in epidermal pattern formation. The EGF receptor and its potential ligands (such as EGF, transforming growth factor (TGF-α) or other yet-to-be-discovered ligands) perhaps act as parts of a pattern-forming system in vertebrate skin. Extra keyword: EGF receptor.

Quantitative and morphological variation of sweat glands, skin thickness, and skin shrinkage over various body regions of Sahiwal Zebu and Jersey cattle

1963 ◽  
Vol 14 (3) ◽  
pp. 424 ◽  
Author(s):  
YS Pan
Keyword(s):  
Sweat Gland ◽  
Mean Value ◽  
The Body ◽  
Sweat Glands ◽  
Skin Thickness ◽  
Jersey Cattle ◽  
Body Regions ◽  
Sampling Position ◽  
The Mean ◽  
Almost All

By comparison with Jerseys the sweat glands of Sahiwals were 70% longer, 55% wider, and 315% greater in mean volume. Total sweat gland volume per unit area of skin was 340%, greater and skin thickness was 60% greater, but skin shrinkage was 30%, less. The density of sweat glands was 1130/cm2 for Jerseys and 1200/cm2 for Sahiwals. In almost all animals the characters varied significantly between the various body positions, and in most cases showed trends. Values for the generally adopted midside sampling position were usually within 10% of the mean value for all positions. Sweat gland shape varied over the body. Most of the shapes observed in the two species were present in one position or another within each animal.

The hair follicle and apocrine gland populations of Zebu (Bos indicus L.) and Shorthorn (B. taurus L.) cattle skin.

1955 ◽  
Vol 6 (4) ◽  
pp. 645 ◽  
Author(s):  
DF Dowling
Keyword(s):  
Hair Follicle ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Age Groups ◽  
Hair Follicles ◽  
Regression Coefficients ◽  
Apocrine Gland ◽  
Apocrine Glands ◽  
Significant Difference ◽  
The Mean

Skin samples taken with a trephine of known size from Shorthorn (Bos taurus L.) and Zebu (B. indicus L.) cattle were used to determine the density of hair follicles and apocrine glands in the skin. The repeatability of the measurement of density on the same animal was found to lie between 78 and 90 per cent. The expansion of the skin as the animal grows, and the manner in which the plane of nutrition can modify growth and so the extent of expansion, has a predominating effect on the hair follicle and apocrine gland density. There is a significant difference between ages, but for each breed the regression coefficients of log follicle number on log heart girth within age groups are not significantly different. The mean number of hair follicles per sq. cm in Zebus was 1698, in Zebu crosses 1321, and in Shorthorns on a low plane of nutrition 1064. In Shorthorns on a high plane the number was 764. All differences were statistically significant.

The sweat glands of Ayrshire cattle

1950 ◽  
Vol 40 (1-2) ◽  
pp. 126-133 ◽  
Author(s):  
J. D. Findlay ◽  
S. H. Yang
Keyword(s):  
Hair Follicle ◽  
Sweat Gland ◽  
Flank Region ◽  
Significant Negative Correlation ◽  
Skin Surface ◽  
Lower Limbs ◽  
Sweat Glands ◽  
Average Area ◽  
Body Regions ◽  
Secretory Products

1. An investigation has been made of the structure, distribution and dimensions of the so-called sweat glands in twenty-one different body regions of each of five 3- to 4-year-old Ayrshire cows, and incidental studies have been made on calves and embryos.2. It has been observed that in all those regions each hair follicle is accompanied by an arrector pili muscle, a sweat gland and a sebaceous gland. This combination has been designated a ‘hair follicle unit’.3. In the skin of embryos the sweat gland appears as a single unbranched tube and in the skin of calves and cows it is a bag-shaped gland with a long slender duct which opens on the skin surface as a funnel-shaped outlet.4. The gland is composed of two layers of cells, an outer myoepithelium and inner glandular epi thelium.5. What may be successive stages in the intraluminal transformation of the secretory products discharged by the gland cells lining the lumen, are illustrated by a series of photographs.6. The glands have a poor blood supply and appear to be apocrine. It is unlikely, therefore, that the sweat glands of Ayrshire cows function as effectively in heat regulation as human sweat glands.7. The number of sweat glands per sq.cm. of skin was measured in all the regions. The average number was 1871 per sq.cm., ranging from about 1000 in the lower limbs to about 2500 in the axilla and neck regions.8. The length and circumference of the gland were measured, hence its secretory surface was calculated. The average area of secretory surface of a single sweat gland was 0·22 sq.mm., while the average area of secretory surface of the sweat glands per sq.cm. of skin was 3·94 sq.cm. There was a significant negative correlation between the number of glands per sq.cm. and the area of secretory surface of a single sweat gland.9. The ventral region of the neck, the axilla and upper hindleg had the largest area of secretory surface per sq.cm. of skin, while the forehead, back (sacral), gluteus, lower foreleg and hindleg had the smallest.10. The only region which had a significantly smaller area of secreting surface than the front flank region was the sacral region of the back.

scholarly journals Comparative evidence for the independent evolution of hair and sweat gland traits in primates

2018 ◽  
Author(s):  
Yana G. Kamberov ◽  
Samantha M. Guhan ◽  
Alessandra DeMarchis ◽  
Judy Jiang ◽  
Sara Sherwood Wright ◽  
...  
Keyword(s):  
Sweat Gland ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Eccrine Gland ◽  
Hair Density ◽  
External Appearance ◽  
Human Feature ◽  
Close Relatives ◽  
Eccrine Sweat Glands ◽  
Eccrine Sweat

AbstractHumans differ in many respects from other primates, but perhaps no derived human feature is more striking than our naked skin. Long purported to be adaptive, humans’ unique external appearance is characterized by changes in both the patterning of hair follicles and eccrine sweat glands, producing decreased hair cover and increased sweat gland density. Despite the conspicuousness of these features and their potential evolutionary importance, there is a lack of clarity regarding how they evolved within the primate lineage. We thus collected and quantified the density of hair follicles and eccrine sweat glands from five regions of the skin in three species of primates: macaque, chimpanzee and human. Although human hair cover is greatly attenuated relative to that of our close relatives, we find that humans have a chimpanzee-like hair density that is significantly lower than that of macaques. In contrast, eccrine gland density is on average 10-fold higher in humans compared to chimpanzees and macaques, whose density is strikingly similar. Our findings suggest that a decrease in hair density in the ancestors of humans and apes was followed by an increase in eccrine gland density and a reduction in fur cover in humans. This work answers longstanding questions about the traits that make human skin unique and substantiates a model in which the evolution of expanded eccrine gland density was exclusive to the human lineage.

scholarly journals Epithelial expression of the hormone leptin by bovine skin

2019 ◽  
Vol 63 (1) ◽  
Author(s):  
Francesca Mercati ◽  
Cecilia Dall'Aglio ◽  
Ludovica Timperi ◽  
Paola Scocco ◽  
Elena De Felice ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Hair Follicle ◽  
Thick Layer ◽  
Proximal Part ◽  
Hair Follicles ◽  
Laboratory Animals ◽  
Sweat Glands ◽  
Rt Pcr ◽  
Morphological Evaluation ◽  
Hair Follicle Growth

Leptin (Lep) stimulates keratinocytes to proliferate, intervenes in the wound healing and participates to hair follicle morphogenesis and cycle. While it is secreted by skin structures including epidermis and hair follicles, intradermal adipose tissue also seems to have a role in Lep secretion and accordingly in the control of hair follicle growth in mice and humans. Lep was investigated in the skin of humans and laboratory animals but there are not data regarding bovine species. The aim of this work was to study the expression of Lep and its receptor (LepR) in the skin of bovine and, at the same time, to investigate the presence and extension of intradermal adipose tissue. A morphological evaluation of the skin was performed while the presence and localization of Lep and LepR were analyzed by RT-PCR and immunohistochemistry. A high and thick dermis without adipocytes was observed. Hair follicles and sebaceous and sweat glands were located in the proximal part of the skin while a thick layer of connective tissue, lacking adipose cells, separated these structures by subcutis. RT-PCR evidenced the transcripts for both molecules. By immunohistochemistry, Lep and LepR were observed in the epidermis and hair follicles. Based on the absence of intradermal adipose tissue and the presence of both Lep and LepR in the epidermis and in the hair follicle epithelium, it can be posited that in bovine skin Lep participates to the control of epidermis growth and hair follicle cycle through a paracrine and autocrine mechanisms.

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