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COMPARATIVE TOPOGRAPHICAL AND HISTOMORPHOMETRICAL
STUDY OF THE HAIR, HAIR FOLLICALE AND HAIR DENSITY IN THE
SKIN OF LOCAL BLACK MALES GOAT
Ghada Abdulrhman sultan Muayad Hasan Abulraheem
Department of Anatomy , College of Veterinary Medicine, University of Mosul , Mosul , Iraq.
(Received 15 November 2020 ,Accepted 21 November 2020)
Keywords: Bucks,hair follicles, Skin.
Corresponding Author: [email protected]
ABSTRACT
The study aimed to undergo a comprehensive study to provide abroad basic data for the
different constituents of the skin of local black goat. To achieve this goal, histological,
morphometrical and topographical study was carried out on twelve skin regions taken from twenty
male apparently healthy bucks. All samples were collected during the autumn season.Two types of
hair follicles were noticed: large follicles that extend deeply into the dermis; Which represented
primary hair follicles, smaller and shorter but more numerous; called secondary hair follicles. The
primary hair follicles produce the coarse hair while the secondary hair follicles produce the fine
hairs. The diameter of the coarse hairs varied in the different skin regions and ranged between
(39.98-106.40 m) being larger in the back and lateral surfaces and smaller in the abdomen and
medial surfaces. The diameter of fine hairs ranged between (26.56-39.94 m). The secondary:
primary hair follicle ratio varies in the different skin regions and accordingly the fine :coarse hair
ratio varies as well. The fine: coarse hair ratio was found to be 6.88:1 in the middle back region,
5.89:1 in the lateral surface of forelimbs region, 5.86:1 in anterior back region, 5.46:1 in lateral
surface of hind limb, 3.64:1in medial surface of hind limb, 3.32:1 in the skin of the
abdomen,3.25:1 in the medial surface of the forelimb, 2.82:1 in the skin of the tail, 2.10:1 in the
skin of scrotum, 0.20:1 in the skin of the muzzle, 0.15:1 in the dorsal surface of skin of the ear and
0.00:1 in the ventral surface of the skin of the ear. Most of the hair follicles of different regions
were of a compound type in which several secondary hairs share the opening of a primary hair
follicle. In less common circumstances, the secondary follicles open directly on the epidermis but
they remain in a close position to the opening of the accompanied primary follicle. Simple hair
follicles were observed in the ventral surface of the skin of the ear, and in a less extent in the
scrotal regions, muzzle region and skin of the dorsal surface of the ear. Hair density varies greatly
in the different skin regions being: 31.68/mm2 in anterior back region, 32.66/mm2 in the middle
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back region,13.38/mm2 in the abdominal region, 32.76/mm2 in the tail region, 30.30/mm2 in the
lateral side of forelimb, 12.50/mm2 in the medial side of the forelimb, 11.52/mm2 in the scrotal
region, 31.12/mm2 in the lateral side of hind limbs, 16.44/mm2 in the medial side of hind limbs,
22.22/mm2 in the muzzle region, 9.62/mm2 in the skin of the dorsal surface of the ear and
2.92/mm2 in the skin of the ventral surface of the ear.
INTRODUCTION
The Skin is protective cover of the body and plays an important role in protecting the body
from external influences, on the one hand and controlling its temperature and humidity on the
other (1). The skin consists of two main layers, the epidermis and the dermis, separated by the
basal membrane.
The epidermis consists of keratinized stratified squamous epithelial tissue that cells goes
through stages of division, migration, differentiation and keratinization until it reaches the surface
layer, where it becomes dead cells that are constantly dissociated from the surface of the epidermis
to be replaced by new keratinized cells, so the epidermis is a model of renewed tissue in the body
(2). The dermis in most parts of the body contains hair follicles, sweat glands and sebaceous
glands , the quality, size and numbers of these components vary depending on the types of animals
and skin areas in one animal. It was reported that hair follicles and sweat glands differ in size,
depth and density in the different types of cows studied (3). Also found difference in histological
composition between certain skin areas in monosyllabic camel (4).
There are many studies on the histological structure of the skin and its attachments in
humans (5). although there were histological studies of the skin of local animals, But it was
limited in the locations of the skin (6). Due to the importance of the local black goat and the
relationship of the skin and hair to the general health condition of the body where hair loss, the
appearance of crusts and the spread of ectoparasites are not due to skin diseases, but rather
diseases affecting the body in general, in addition to the economic importance (7). And the lack of
current study of hair density in different areas of the skin and compare with each other. so the
main objective of this research is to know the histological composition of hair and hair follicles, in
addition to knowing the density of hair in different areas of the skin and comparing it with each
other .
MATERIALS AND METHODS
Sample collection:The research samples (skin) were taken from local Black Goat males aged 1-2
years after being slaughtered immediately and clinically sound especially skin from the Mosul
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massacre. All samples were taken in the autumn only to avoid changes that may occur on the skin
in different seasons (8).
20 animal skins were used and the areas to be taken from the skin were marked with a colored
marker pen be forelimb slaughter. After the slaughter, the hair was cut from the marked areas and
4-6 samples were taken from each area using the Punch set with the following diameter
information and anatomical locations: (front back, middle back, abdomen, tail, lateral surface of
the forelimb, medial surface of the forelimb, scrotum, lateral surface of the hind limb, medial
surface of the hind limb, muzzle(snout), dorsal and ventral surface of the ear ).
Histological and Morphological Study:Samples were held in Alcoholic Bouin's solution for 48
hours and then transferred to 4% phenol for 24 hours to reduce the hardness of the keratinized
substance in the skin.The samples were treated with Ethyle alcohol for the purpose of increasing
concentration for the purpose of dehydration starting from 50% concentration with several passes
until the yellow color of the stabilizer than 70% , 90% and 100% concentration also with two
passes at a rate of 3 hours.
Cedar wood oil was used at the rate of one pass for 24 hours for softening, after which the
samples were transferred to Benzen for half an hour (9). And then the samples were passed into
pure, paraffin wax the melting-grade 58 - 60 ℃, inside the electric oven temperature 60℃ . Some
samples were placed in molten wax exposed to negative pressure using a vacuum pump type
C7960 to facilitate the influence of wax to the samples (10). At a rate of 4 passes, one hour was
allocated for each pass and then the samples were poured into clearly marked wax molds (9). Half
of the models were immersed in a vertical position inside the wax and the other half in a
horizontal position to survey all skin structures and infer on their measurements. The models were
cut using the Rotary microtome to obtain 5-8 micrometer thick tissue strips and fixed on glass
strips mediated by a light layer of Egg albumin or so-called Mayer's adhesive (10). The following
stains were used to show the different histological textures:
1- Delafield's hematoxylin and eosin were colored for the general histological structure of the
skin and for the preparation of microscopic measurements (10).
2- Masson's Trichrome stain to differentiate between collagen and muscle fibers in skin (9).
The standard morphometric study was carried out under the optical microscope using the
Ocular micrometer and the Stage micrometer standard measurement and extraction of the
Micrometer standard value of each object lens. And calculated the microscopic standard value of
all the lenses of the microscope, so it was as it comes :
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Table (1):The use of the Micrometer Value (μm) standard for models measured with
different object lenses of the optical microscope
The following variables has been measured:
1- The length and depth of the primary follicle.
2- The length and depth of the secondary follicle.
3- The diameter of the primary and secondary follicle and the diameter of the hair in the primary and
secondary follicle.
To confirm the accuracy of the microscopic measurements, they were compared to the method of
measuring Visopan (Reichert, Austria Nr. 366 F15).
Microscopic
Zoom power standard value The power of
the object lens
4/0.10 50 20
10/0.25 125 8
16/0.32 200 5
40/0.65 500 2
63/0.80 800 1.2
100/1.25 1250 0.8
Table (2):Extract the microscopic measurement value of Visopan object lens models as
found in the device manual itself
Study of hair density: Hair density is calculated by enumerating the hair follicles of Adenomeres per
unit area and as it comes و the horizontal sections below the level at which the sebaceous glands open
to the hair follicles were selected to ensure the presence of primary and secondary hair follicles.
The area of the Microscopic field was calculated by calculating the diameter of the microscopic
field of the microscope in the object lens in which it was examined and extracted the surface area
of the microscopic field using the usual geometric method.
The study aimed at what comes:
1- Find the number of primary hair follicles per unit area in different skin areas.
2- Find the number of secondary follicles per unit area in different skin areas.
Microscopic
standard value
Power of the
object lens
4 34.4
10 13.3
40 3.3
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3- Find the total number of hair follicles per unit area in different skin areas.
Microphotography:photographed tissue sections using a digital camera and a light microscope
(Reichert, Neovar) mediated by Adaptor.
Calculation of Magnification:
Zoom power =
Statistical analysis :The data for the study were analyzed using the one way analysis of variance
test and using the Duncan test to identify statistical differences between different areas of the skin
(11). and examined the moral differences in all tests at the level of P<0.001.
RESULTS
This study showed that local black goat skin consists of two main layers, the epidermis and
dermis, hypodermis is another layer which is located under the dermis formed from loose
connective tissue which connect the skin to the underneath tissues .
Hair and Hair Follicles: The hair is an elongated keratinous structure that is mediated by the hair
follicle in the primary and secondary follicles.The root of the hair in the primary and secondary
follicles consists of three layers the outer layer is the cuticle composed of a single row of flat
keratinized cells whose free edges are directed towards the distal end of the hair shaft, and the
middle layer is the cortex composed of monolithic keratinized cells as their longitudinal axes
appeared parallel to the hair shaft, containing the remnants of the nuclei and pigment granules.
These cells become shorter, oval in shape and contain spherical nuclei near the hair follicle. The
third inner layer, the medulla, contains disintegrated cubic or flat cells with air gaps (Fig. 1).
The results of the study of goat skin showed that there are two types of hair in the domestic
black goat skin. Coarse hair composed of Marrow and cortex and cuticle starch from primary
follicles and soft hair devoid of Marrow starch from secondary follicles and the diameters of both
types differed by different areas of the body studied as the diameters of coarse hair ranged from
(66.50-106.40 μm ) as the outer skin areas such as the back and the lateral surfaces of the
Measure the value of a certain number of microscopic ruler divisions after
The number of divisions themselves × 10
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forelimb and hind limb large diameters of coarse hair or hair resulting from the primary follicles if
compared to the medial surfaces of the limbs , back and abdomen, as shown in Table (3).
On the other hand, the diameters of the fine hair produced by the secondary follicles in the
lateral surfaces of the forelimb and hind limb , back and tail were larger than in the lateral
surfaces of the forelimb and hind limb , abdomen and scrotum and their diameters ranged from
(26.56-39.94 μm). As in the Table (3).
The results of this study showed a convergence in the diameters of the hair located in the area
of the muzzle (39.88-46.62 μm) as well as in the ventral surface area of the ear skin where the
average diameter of the hair (39.88 μm) may be due to the absence of secondary follicles. Hair
follicles are morphological structures that extend oblique into the dermis.
The hair follicle consists of two sheaths surrounding the root of the hair, the internal root
sheath, the components of which are visible in the distal third of the hair follicle and consists of
three layers, the internal cuticle layer, which is formed by keratinized cells and overlapping with
the hair cuticle is followed by Huxley's layer, which consists of one to three rows of keratinized
cells rich in Trichohyaline granules, which are pigmented in red and gradually disappear towards
the surface of the skin. while Henle's layer appeared to be composed of a single row of keratinized
vertical cells whose longitudinal axes are directed towards the longitudinal axis of the follicle, the
inner root sheath appeared wrinkled just below the site of the sebaceous glands, and in the large
follicle several follicular folds appear, which then disappear into the upper level of the sebaceous
gland ducts.
The results of the histological examination of the vertical sections prepared from different areas
showed that the outer root sheath connects to the cells of the basal and spinal layer of the
epidermis in the upper part of the follicle, as it consists of several layers of cells similar to the cells
of the endothelial layer of the epidermis and gradually decreases in thickness towards The hair
matrix cells appeared as cubic cells surrounding the dermal papilla of the hair, forming most of the
hair follicle .The outer root sheath of the follicle is separated from the dermis by the Glassy
membrane, which is glistening with the use of Masson's Trichrome stain of the horizontal
segments (Fig.2) and the outer root sheath is surrounded by a layer of dense connective tissue
composed of elastic fibers forming a third sheath of dermal connective tissue.
The results of the research showed that the hair follicles in the goat skin differ in size and
degree of extension in the depth of the dermis, the primary hair follicles are large in size and
extend deep into the dermis, the secondary follicles are smaller, more numerous and shorter length
Table (4) and a number of them meet with the primary hair follicle place of opening of sweat and
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sebaceous glands It forms a single hairy channel, through which several hairs exit from one
opening (Fig. 3).
Most of the areas studied appeared in these follicles called compound follicles except the areas
of the snout and ear surfaces, since most of the follicles were of the simple type, and some simple
follicles appeared in the skin of the tail and scrotum as these follicles opened independently on the
skin. (Fig. 4) a difference in the diameters of the primary follicles taken in the level of the
sebaceous glands was shown as the dermis of the skin of the back and tail and the lateral surfaces
of the forelimb and hind limb were characterized by containing large diameter follicles when
compared to the skin of the ear with their surfaces, the snout, abdomen, scrotum and the lateral
surfaces of the limbs as shown in Table.( 5 ). Some secondary follicles appeared surrounded by
sebaceous glands only, but there is no relationship between them and the sweat glands and all the
areas studied.
The diameters of the secondary follicles ranged from (53.20-86.54 μm) as shown in Table(5)
from the observation of the table we find the diameters of the secondary follicles larger in the
forget surfaces of the forelimb and hind limb and the skin of the abdomen, scrotum, ear and
snout. If compared with the diameters of the secondary follicles of the skin of the back, the lateral
surfaces of the forelimb and hind limb and the skin of the tail .
Using Masson's Trichrome stain, the dermis of all the areas studied except the snout appeared to
have a red smooth muscle, the arrector pill muscle , which was associated with the primary
follicle. This bundle of smooth fibers paired with some elastic fibers extends at the protruding
angle formed from the confluence of the primary follicle with the skin surface and extends from
the lower third of the primary follicle to the papillary layer of the dermis.
As a result of microscopic examination of the prepared slide of the routinely colored horizontal
segments and different areas of the skin, we observed a difference in the arrangement of the
primary follicles, as the general triangular arrangement of the follicles emerged as there was a
central follicle slightly larger than the lateral follicle and these follicles were arranged linearly in
most of the studied areas (Fig.5).
But a triangular arrangement was found in dermis of abdomen skin (Fig.6) . Secondary follicles
are not regularly distributed around the primary follicle in most follicular organizations, but
secondary follicles are organized on one side of the primary follicle, called the Ectal side hair. The
sebaceous glands, the canal of the sweat gland and the arrector pill muscle are organized on the
opposite side, which is called the glandular side (Ental side) (Fig.5), in addition to the triangular
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Organization of the follicles, the single, bilateral, quadruple and pentagonal arrangement was also
found (Fig. 7,8,9,10) respectively.
It was found that there was a clear difference in the hair density per unit area, as these numbers
varied in the different areas studied. The skin of the abdominal surface of the ear contains the
lowest number of follicles (2.92/mm2) as shown in Table (6). On the other hand, the results of our
study showed a difference in the ratio of secondary to primary follicles with different areas studied
Table (6). The area of the middle back, front back and lateral surfaces of the limbs showed the
highest proportion of secondary follicles, while this ratio decreased to almost zero in the area of
the snout and the dorsal and ventral surface of the ear .
Sinus Hair Follicles: Some sinusoidal hair follicles appeared in the dermis of the scrotum and the
muzzle and were characterized by their large size in the scrotum skin, reaching a length (2527 μm)
and a diameter (292.6 μm) at the level of the blood sinus, which can be observed filled with blood
between the inner and outer layers of the connective tissue sheath (Fig.11). Structural muscle
fibers can also be seen in the outer part of the connective tissue sheath. Sinusoidal hair follicles
were not seen in other skin areas studied.
Table (3): The average hair diameter in primary and secondary follicles and the level of
sebaceous glands for different areas of local black goat skin (μm)
Anatomical sites for sampling
of skin
The diameter of the
hair in the primary
follicle
The diameter of the
hair in the secondary
follicle
1.51 39.92 14.91 98.46 Front back
5.48 35.96 4.08 A106.40 Middle back
2.23 29.56 5.97 90.36 Abdomen
2.82 33.34 14.02 99.7 Tail
3.27 35.86 4.08 106.4 lateral surface of the forelimb
3.41 29.64 1.92 89.04 medial surface of the forelimb
1.74 B*26.56 7.52 79.8 Scrotum
1.7 A*39.94 5.25 106.38 lateral surface of the hind limb
2.7 30.64 2.82 86.52 medial surface of the hind limb
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A laterally represents the highest rate of hair diameter in the primary follicle at a probability level P <0.001.
B horizontally represents the lowest average hair diameter in the primary follicle at a probability level P <0.001.
A * horizontally represents the highest average hair diameter in the secondary follicle at a probability level P <0.001.
B * horizontally represents the lowest mean of hair diameter in the secondary follicle at a probability level P <0.001.
All numbers within the table are standard Standard deviation.
Table (4): The primary and secondary follicle lengths and depth within the dermis in
different areas of local black goat skin using a (μm)
Anatomica
l sites for
sampling
of skin
Fr
ont
ba
ck
Mi
ddl
e
bac
k
A
bd
o
m
en
Tail
latera
l
surfa
ce of
the
foreli
mb
medi
al
surfa
ce of
the
foreli
mb
Scrot
um
lateral
surface
of the
hind
limb
medial
surfac
e of
the
hind
limb
Muzzl
e
dors
al
surfa
ce of
the
ear
ventral
surface
of the
ear
Primary
follicle
length
20
68.
4
A2
180
.60
17
28
.8
2127
.6
1869.
2
1795.
4
931.4 1820.2 1835 1766
597.
8
B465.0
0
22
0.1
3
144
.79
18
1.
18
266.
5
147.6
1
418.3
8
59.58 126.48 85.91
200.0
9
140.
36
125.78
Depth of
the
primary
follicle
18
07
A*
204
8.0
0
15
95
.6
1968
.2
1700.
8
1662.
2
1621.
2
797.6 1677.4 1687.2
371.
6
B*332.
00
24
5.0
1
157
.89
77
.9
5
140.
4
46.13 94.9
119.3
8
50.61 163.82 83.84
34.7
1
56.32
Secondary
follicle
length
11
30.
2
A*
*13
29.
60
83
4.
6
765.
6
1014.
4
664.6 864 1063.8 798 931
B**
398.
60
--------
3 39.88 6.91 46.62 Muzzle
4.73 39.88 7.68 66.5 dorsal surface of the ear
-------- 6.07 B39.98 ventral surface of the ear
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62.
19
113
.36
14
0.
45
31.7
5
77.6 50.61 98.57 87.94 8.6 68.07 86.63
Depth of
the
Secondary
follicle
99
6.8
A*
-
119
7.4
0
70
4
622.
8
531.6 730.8 931 665.2 794.8 876.2
B*-
265.
60
--------
19
4.7
3
170
10
4.
95
86.1
9
124.7
9
30.65
101.8
6
42.21 105.83 110.96
21.0
3
A laterally represents the highest pimary follicle length at a P <0.001 probability level. B laterally represents
the minimum primary follicle length at a P <0.001 probability level.
* A laterally represents the highest primary follicle depth at a P <0.001 probability level. B * horizontally represents
the minimum primary follicle depth at a P <0.001 probability level.
** A laterally represents the highest secondary follicle length at a P <0.001 probability level. B ** horizontally
represents the lowest secondary follicle length at a P <0.001 probability level.
A * - horizontally representing the highest secondary follicle depth at a P <0.001 probability level. B * - horizontally
representing the minimum depth of the secondary follicle at a P <0.001 probability level.
All numbers inside the table are rates of standard deviation.
Table (5): The average of primary and secondary follicle diameters at the level of the
sebaceous glands of the different areas of the local black goat skin (μm)
Anatomical sites for sampling
of skin
Diameter
of the
primary
follicle
Diameter
of the
secondary
follicle
8.47 66.52 9 252.72 Front back
3.11 67.84 13.28 259.36 Middle back
4.56 81.12 8.88 238.12 Abdomen
5.82 B*53.22 13.88 246.14 Tail
4.45 62.52 5.43 248.68 lateral surface of the forelimb
4.58 86.64 5.8 235.42 medial surface of the forelimb
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A laterally represents the highest rate of primary follicle diameter at a probability level P <0.001.
B horizontally represents the lowest rate of primary follicle diameter at a probability level P <0.001.
A * horizontally represents the highest rate of secondary follicle diameter at a probability level P <0.001.
B * horizontally represents the lowest mean of secondary follicle diameter at a probability level P <0.001.
All numbers inside the table are the mean standard deviation.
Table (6): The numbers of primary and secondary follicles using the square millimeter unit
of measurement and the ratio of primary to secondary follicles in different areas of local
black goat skin
13.61 A*86.54 21.36 239.44 Scrotum
5.77 66.5 5.75 A272.62 lateral surface of the hind limb
8.78 79.8 5.13 232.72 medial surface of the hind limb
2.11 69.2 3.43 B109.06 Muzzle
11.45 70.52 4.23 126.36 dorsal surface of the ear
--------- 5.35 113.06 ventral surface of the ear
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Anatomical sites for sampling of
skin
Total
follicle
count
The
number
of
Primary
follicle
The
number
of
secondary
follicles
The ratio of
primary to
secondary
follicles
5.86:1 4.65 27.04 0.41 4.64 4.36 31.68 Front back
A-6.88:1 5.55 A**28.52 0.72 4.14 6.01 32.66 Middle back
3.32:1 1.2 10.28 0.45 3.1 0.88 13.38 Abdomen
2.82:1 4.6 22.76 0.6 10 4.16 A32.76 Tail
5.89:1 3.19 25.9 0.31 4.4 3.13 30.3 lateral surface of the forelimb
3.25:1 1.27 9.56 0.37 2.94 1 12.5 medial surface of the forelimb
2.10:1 0.95 7.8 0.58 3.72 1.18 11.52 Scrotum
5.46:1 2.38 26.3 0.3 4.82 2.26 31.12 lateral surface of the hind limb
3.64:1 1.26 12.9 0.36 3.54 1.21 16.44 medial surface of the hind limb
0.2:1 0.59 3.7 2.92 A*18.52 2.92 22.22 Muzzle
0.15:1 0.15 B**1.24 0.66 8.38 0.74 9.62 dorsal surface of the ear
B-0.00:1 ------- 0.46 B*2.92 0.46 B2.92 ventral surface of the ear
A laterally represents the highest rate of total follicle count at a probability level P <0.001. B laterally represents the
lowest mean total follicle count at a P <0.001 probability level.
* A horizontally represents the highest rate of primary follicle count at a probability level P <0.001. * B horizontally
represents the lowest mean number of primary follicles at a probability level P <0.001.
** A horizontally represents the highest rate of secondary follicle count at p <0.001a probability level. ** B
horizontally represents the lowest mean number of secondary follicles at a P <0.001 probability level.
Horizontally, the highest ratio of primary to secondary follicles is represented by a P <0.001 probability level.
Horizontally, B represents the lowest ratio of primary to secondary follicles at a probability level P <0.001.
All numbers inside the table are the mean standard deviation.
Bas.J.Vet.Res.Vol.19, No.2, 2020.
Figure 1. A horizontal section taken from the lower third of the epidermis of the lateral surface of
the forelimb. The Figure 2. Horizontal section of the skin of the lateral surface area of
membrane glm around primary follicle PF with cross sections of SF secondary follicles(Hematoxylin
and Eosin stain, X165).
186
he medulla M, the cortex C, the inner root sheath IRSH, the outer root sheath
ERSH with the presence of the SU secretory units of the apical sweat glands and the presence of
the myofilaments epithelial cells MY (
Masson's Trichrome stain, X 240).
the forelimb.
The glassy
Bas.J.Vet.Res.Vol.19, No.2, 2020.
Figure 3. A vertical section of the skin of the medial surface region of the hind limb . The large
size and deep extension of the primary follicle PF into the dermis and the small size of the
secondary follicle SF and its low extension into the dermis
Figure 4. secondary hair follicles SF which open in close proximity to the primary follicle. (Hematoxylin
and Eosin stain, X46).
SF
187
(Hematoxylin and Eosin stain, X75).
A vertical section of the skin of the scrotum. The Primary hairs follicle PF and
P F
Bas.J.Vet.Res.Vol.19, No.2, 2020.
Figure 5. Horizontal section of the skin of the lateral surface area of
arrangement arranged in alignment of the primary follicles with secondary follicles being present,
the Eosin stain, X 165).
Figure 6 .(Hematoxylin and Eosin stained, X165).
188
the forelimb. The triangular
sebaceous glands, the sweat gland duct, and the epithelium muscle occupied the Ental side,
while the secondary follicles occupied the opposite side, called the Ectal side (Hematoxylin and
A horizontal section of the skin of the abdominal region. The triangular arrangement of
the primary follicles PF with the presence of secondary follicles SF and sebaceous glands SBG.
Bas.J.Vet.Res.Vol.19, No.2, 2020.
Figure 7.Horizontal section of the skin of the lateral surface of the hind limb, The single
arrangement of primary follicles PF with Secondary follicle SF. (
165).
Figure 8.Horizontal section of the skin of the lateral surface area
arrangement of primary follicles PF with secondary follicles SF and the duct of the apical
secretory gland CSG. (Masson's Trichrome stain, X 165).
189
Hematoxylin and
.of the hind limb. The binary
ematoxylin Eosin Stain, X
Bas.J.Vet.Res.Vol.19, No.2, 2020.
Figure 9.Horizontal section of the skin of the lateral
The quadrilateral arrangement of primary follicles PF with secondary follicles SF and sebaceous
glands SBG and sweat gland duct is apical secreting CSG. (Hematoxylin and Eosin stain, X90).
Figure 10.190
surface area of the forelimb.
Horizontal section of the skin of the tail region. The pentagonal arrangement of primary
follicles PF with low numbers of SF secondary follicles. (Hematoxylin and Eosin stain, X 115).
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Figure 11.Vertical section of the skin of the muzzle . Tactile hairs follicular THF are
distinguished by their large size and the presence of the blood sinus ( )between the inner
layer of the connective tissue sheath K and the outer layer has L. (Hematoxylin and Eosin stain, X
90).
DISCUSSION
Hair in mammals an elongated horny structure found in the skin covering all parts of the
body except for the foot pads, hooves, and the outer parts of the genitals, nipples and lips
(12).This is consistent with the results of our study where it appeared the hair located in the hair
follicle Centre in the primary and secondary follicle and distributed unevenly in the regions
studied.
The results of the researchers in different animals agreed with results of our research in
goats that the hair is composed of three parts: the hair shaft, the hair root and the hair bulb(13).
Our results also showed the presence of two types of hair in the local black goat skin: coarse and
long hair composed of marrow, cortex and cuticle which originating from the primary follicle
and forming the outer hair cover of the skin as confirmed by (14, 15). And soft hair smaller
diameter free from the marrow which arise from the secondary follicle forming the inner hair
cover ,as indicated by this is (16). In his search for the skin of Kashmiri goats under stressed (17).
The presence of this difference in his study of the types of woolen fibers of some genetic
aggregates of Iraqi sheep.
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The diameters of both types of hair differed: coarse hair appeared with diameters ranging
from (39.98-106.39 μm) and fine hair appeared with diameters ranging from (26.56-39.94 μm).
The diameter of the hair in both types of follicles in the skin of the back and the lateral surfaces of
the limbs and the tail was larger than in the skin of the scrotum, the ear with its two surfaces and
the lateral surfaces of the limbs and the skin of the abdomen. In the snout, the hair diameters
ranged from(39.88-46.62 μm) which is consistent with what said in his study of the qualities of
some body measurements and the physical qualities of local goat hair (18).
Where this researcher pointed out that the hair diameters are different between areas of the
body and the rate of hair diameter was high (105.46 μm) in the right side of the animal and at the
level of the last rib, while our results showed that the rate of hair diameter in the primary follicle
ranged from (39.98 μm) for the skin of the ventral surface of the ear and (106.40 μm)in the skin of
the back and the lateral surface of the limbs in the primary follicles and for the rest of the areas
between these two numbers.
The average hair diameter in the secondary follicles ranged from (26.56 μm) in the skin of
the scrotum and (39.94 μm) for the skin of the lateral surface of the hind limb and for the rest of
the areas between these two numbers.
Our results clearly showed at the level of the distal third of the hair follicle that the hair
follicle at this level consists of the inner root sheath consisting of three layers from the inside to
outside , the inner cuticle layer followed by Huxley's layer and Henle's layer, which is consistent
with (19 , 20 ) in humans and different areas of the body and in different animals (21 , 22 ). The
internal root sheath appeared wrinkled just below the site of the sebaceous gland and in the large
follicles where several follicular folds appeared, which then disappear where they do not appear in
the upper levels of the sebaceous gland ducts in American goats (23).
The outer root sheath appeared composed of several layers of cells similar to the cells of
the germinativum layer of skin epidermis. This is due to the connection of the outer root sheath
with the cells of the basal and spinal layer of the epidermis in the upper part of the follicle. This is
consistent with (21) in different animals. The follicle was separated from the dermis by a glassy,
shiny membrane where it appeared clear by using Masson's Trichrome stain (19) in humans and
(22) in different animals and for different areas of skin.
classified hair follicles in this study, depending on the size and degree of extension in the
depth of the dermis and its relation to the skin glands to long and large hair follicles are primary
hair follicles and smaller, more numerous and shorter follicles are secondary hair follicles. also
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noted this in American goats(23). And matched that (24,17) in Iraqi sheep for different areas of
the body.
This results and some of the studied areas showed that some secondary follicles open
independently on the skin, but close to where the primary follicles open. this is consistent with
(25) in Iraqi goats, and (23) in American goats. secondary follicles often meet with the primary
hair follicle at the level of the opening of the sebaceous and sweat glands, forming a single hair
channel from which several hairs emerge from a single opening.
These are called composite follicles, which have appeared in all the studied areas and in
different numbers. Except for the skin of the snout and the dorsal surface of the ear, where
composite follicles appeared in very small numbers when compared to simple follicles that
appeared in large numbers in these areas. The ventral surface of the ear is characterized by the
presence of only simple follicles, while the skin of the tail and scrotum have very few simple
follicles.
The presence of simple follicles in some areas of the skin of domestic goats has not been
indicated in the available research, as research indicates the presence of compound follicles only
in the skin of American goats (23). Iraqi goats (25). In Awassi sheep (17). In Camel (4).
While researchers (3). Study hair follicles in the skin of large ruminants, cow , buffalo is
kind of simple as well as in human (26,27). The primary follicle diameters varied according to the
areas studied and appeared in the skin of the back, the lateral surfaces of the limbs and the skin of
the tail with large diameters when compared to the primary follicle diameters in the skin of the
abdomen, the snout, the scrotum, the medial surfaces of the limbs and the dorsal and ventral
surfaces of the ear, as they were smaller in diameter .accordingly, the hair diameters of the medial
surfaces are smaller than in the back and lateral surfaces of the limb.
The results of our study are consistent with the presence of differences in the diameters of
hair follicles with (25). indicated in local goats and specific areas of the body where they indicated
the presence of primary follicles with large diameters in the skin of the back followed by the skin
of the abdomen and smaller than that in the skin of the scrotum, in this area. These results also
showed a difference in the intradermal extension of primary and secondary follicles in the skin
areas studied .In general, it has been observed that there is a direct relationship between the
amount of follicle extension and the thickness of the dermis. There is no indication of this
relationship in the available research
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.
The hair density calculated in a particular area varied according to the areas studied where
the tail skin was characterized by a high hair density of (32.90/mm2) while the lowest hair density
appeared in the skin of the abdominal surface of the ear reaching (2.92/mm2)only. While reported
that the hair density of goat skin was (10.00/mm2) in the skin of the abdomen, (30.99/mm2) in the
skin of the back, the researchers indicated that the hair density was low (14.12/mm2) in the
inguinal area followed by (22.00/mm2) in the skin of the armpit and the highest hair density in
the back skin(25). The hair density of the skin of the back in the battered sheep was (53.00/mm2)
(28). While the hair density of the front back (17.16/mm2) was lower than the middle back
(20.00/mm2) in the awassi sheep(24).
This is consistent with the results of our study, where the hair density of the front back
(31.68/mm2) was lower than the middle back (32.66/mm2), but the number of total follicles was
higher in our results and this may be due to the difference of gender, sex and age where these
elements have a clear effect .
The ratio of primary to secondary follicular density varied in the different areas studied
and since the primary follicular density :secondary in the areas of the middle back.
The highest density of fine hair was (28.52 / mm2) in the area of the middle back and the
lower density in the areas of the front back and the lateral surface of the hind limb and then the
lateral surface of the forelimb and the lower density of fine hair in the skin of the dorsal surface of
the ear (1.24/mm2), which indicates that the secondary hair follicles are more abundant in the
areas of the back and the lateral surfaces of the limbs , This leads us to the fact that hair in these
areas is of good quality and can be used in economic industries.
The arrangement of the follicles in the goat skin differed, the triangular arrangement was
predominant in all the studied areas and this was confirmed by (29) in the black bankali goat, but
the single and bilateral arrangement was also present and this is consistent with what was
indicated by (25) in the local goat. Quadrangular and Pentagram groups have also appeared in
varying proportions in the skin of the back, tail and lateral surface of the front limbs only and
studies are not available on the presence of Quadrangular or pentagram groups in the skin of local
black goats. Most of the secondary follicles are organized in the Ectal side of the primary follicle,
the glandular side is located in the sebaceous gland, the sweat gland canal and the hair follicle,
which is consistent with what he pointed out (12).
An exception is the skin of the dorsal surface of the ear, where we observe secondary
follicles distributed around the primary follicles and this may be due to the absence of the
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sebaceous gland on one side for its large size, which does not allow the secondary follicles to
regularize on one side.
The erector pill muscle stretched from the lower third of the primary follicle to the
papillary layer of the dermis. It is thought to act on the erection of hair during cold or fear, as
mentioned (15) in various animals.
Tactile hair follicles appeared in the dermis of the skin of the snout and scrotum,
characterized by their large size and length with the appearance of a bloody sinus and not found in
the rest of the studied areas (23). indicated that they are present in the dermis of the skin of the
snout and eyelid of the American Goat. The presence of sinus hair follicles in specific areas
corresponds to the highly specialized nature of their function in tactile sensitization (21).
دراسة نسیجیة وشکلیة قیاسیة وطبغرافیة مقارنة للشعرة ، الجریبات الشعریة والکثافة الشعریة
لجلد ذکور الماعز الأسود المحلی
غادة عبدالرحمن سلطان، مؤید حسن عبدالرحیم
فرع التشریح ، کلیة الطب البیطری ، جامعة الموصل ، الموصل ، العراق
الخلاصة
ھدف البحث إلى إجراء دراسة شاملة لتوفیر قاعدة معلومات أساسیة لمکونات جلد الماعز الأسود المحلی، ولغرض الوصول
إلى ھذا الھدف فقد تم إجراء دراسات نسیجیة وشکلیة قیاسیة وطبغرافیة مقارنة لاثنتی عشرة منطقة من جلد الماعز الأسود
المحلی واستعمل لھذا الغرض جلد ٢٠ حیواناً ذکراً بالغاً سلیماً صحیاً وتم اخذ النماذج فی فصل الخریف لوحظ وجود نوعین من
جریبات الشعر: جریبات کبیرة الحجم وتمتد عمیقا فی الأدمة ھی جریبات الشعر الابتدائیة واخرى اکثر عددا واصغر حجما واقل
عمقا ھی جریبات الشعر الثانویة. تنتج الجریبات الابتدائیة الشعر الخشن، بینما تنتج الجریبات الثانویة الشعر الناعم. تباینت أقطار
106.40 ) میکرومیتر بینما تراوحت اقطار الشعر الناعم فی المناطق المختلفة - الشعر الخشن فی المناطق المختلفة بین ( 39.98
39.94 ) میکرومیتر وتباینت نسبة الجریبات الابتدائیة الى الثانویة وبالتالی الشعر الخشن الى الشعر الناعم باختلاف - بین ( 26.56
مناطق الجلد، فقد بلغت نسبة عدد الشعر الخشن الى الناعم 6.88:1 فی جلد الظھر الوسطی و 5.89:1 فی جلد السطح الوحشی
للقائمة الأمامیة و 5.86:1 فی جلد الظھر الأمامی و 5.46:1 فی جلد السطح الوحشی للقائمة الخلفیة و 3.64:1 فی جلد السطح
الأنسی للقائمة الخلفیة و 3.32:1 فی جلد البطن و ٣.٢٥:١ فی جلد السطح الأنسی للقائمة الأمامیة و 2.82:1 فی جلد الذیل و
2.10:1 فی جلد الصفن و 0.20:1 فی جلد الخطم و 0.15:1 فی جلد السطح الظھری للأذن واخیرا 0.00:1 فی السطح البطنی
للأذن. کانت الجریبات فی معظم المناطق المدروسة من النوع المرکب حیث تلتقی الجریبات الثانویة مع الجریبات الابتدائیة فی
مستوى انفتاح الغدد الزھمیة والعرقیة مکونة قناة شعریة واحدة تخرج منھا عدة شعرات من فتحة واحدة. وقد تفتح الجریبات
الثانویة على السطح مباشرة ولکنھا قریبة جدا من مکان انفتاح الجریبة الابتدائیة. توجد الجریبات البسیطة فی جلد السطح البطنی
للأذن وبأعداد اقل فی جلد الصفن والخطم والسطح الظھری للأذن. تختلف الکثافة الشعریة باختلاف المناطق المدروسة حیث
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کانت الکثافة الشعریة کالآتی: الظھر الأمامی 31.68 / ملم ٢، الظھر الوسطی 32.66 /ملم ٢، والبطن 13.38 /ملم ٢، الذیل
32.76 /ملم ٢، السطح الوحشی للقائمة الأمامیة 30.30 /ملم ٢، جلد السطح الأنسی للقائمة الأمامیة 12.50 / ملم ٢، جلد الصفن
/ 11.52 / ملم ٢، جلد السطح الوحشی للقائمة الخلفیة 31.12 / ملم ٢، السطح الأنسی للقائمة الخلفیة 16.44 /ملم ٢، الخطم 22.22
. ملم ٢، جلد السطح الظھری للأذن 9.62 / ملم ٢، السطح البطنی للأذن 2.92 /ملم ٢
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