<div>The present study was aimed to examine histochemical changes in the Harderian gland of pre and post hatched chicks from 11 day of incubation to 24 days of age. In pre hatched groups, the gland was in the developing stage. There was no well defined parenchyma, septa and capsule in early embryonic stage. Histochemical observation revealed that weak or negligible activity of PAS, AB/PAS and Sudan black B was seen in epithelial lining of Harderian gland on 18th and 20th day of incubation. The gland was compound tubule-acinar type at 20th day of incubation, consisted of capsule, parenchyma and stroma. PAS activity was seen in the capsule, septa, epithelial lining of acini and tubule and interstitial connective tissue cells. PAS activity was aggregated towards the apical part of the tubular epithelium as well as at the free luminal surface epithelium of the acini. PAS activity increases with the development of connective tissue component of Harderian gland with the advancement of age. The Harderian gland was predominantly mucus and lipid secreting gland. All epithelial cells of the glandular unit of Harderian gland contain both neutral and acidic mucin. Intense AB-positive activity was seen at the apex of tubule with the advancement of age. Sudan black B activity was recorded in the cytoplasm of epithelial lining of tubule and acini of the Harderian gland and their presence increases with age.&nbsp;</div>


<div>Histochemical changes during development of Harderian gland in chicken</div>


<div style="text-align: justify;">In the present investigation, 6 numbers of each apparently healthy adult Pati duck and local fowl of Assam were utilized for detailed gross, histomorphological, histochemical and ultrastructural studies. The Harderian gland in the Patiducks &nbsp;and Fowl were located in the medioventral region of the orbital cavity attached along with the eye ball. The gland was not having any grossly demercablelobulation but still there was dorsally slightly narrow part whereas the ventral part was somewhat more wider. In duck, from the capsule, thin connective tissue septa penetrated into the gland and divided parenchyma it into lobes and lobules which were unequal and polygonal in shape. Each lobule contained a central lumen. From the capsule and septa thin streaks of interstitial connective tissue penetrated between the acini and tubules. The columnar epithelial cells lining the acini showed considerable variation in height depending on their functional state. The nerve fibers were also extending from the capsule inside the parenchyma along with the other connective tissue fibers. Harderian gland of Fowl was also covered with a thin connective tissue capsule and consisted of coarse collagen, fine reticular and elastic fibers, blood vessels, &nbsp;and nerve fibers, which were penetrating the parenchyma very frequently by forming septa and trabeculae. The glands were to be of multilobulartubulo-alveolar type and emptied into a wide lumen which was lined by columnar epithelial cells. The histochemical sections were found positive for PAS Alcian blue. The reaction for acid phosphates and alkaline phosphatase were also moderate to intense in the harderian gland. The scanning electron microphotograph of harderian gland showed the acini, secretory granules and connective tissue fibers in the duck and fowl. The secretions of the gland were accommodated inside the acini and looks like a woollen ball.&nbsp;</div>

Macro and Micro anatomical study of Harderian Gland of Duck and Fowl

<p><strong>Background: </strong><em>Pati</em> duck population constitutes a major indigenous non-descript economically important duck variety in Assam. Harderian gland acts as a part of the head associated lymphoid tissue (HALT) and provides local innate immunity to the upper respiratory system, to the eye and oral cavity. Since literature on histoenzymic or histochemical study of harderian gland of<em> Pati </em>duck was scant, hence the present study was designed to establish the basic histoenzymic details on harderian gland of<em> Pati</em> duck of Assam.<br />
<br />
<strong>Methods: </strong>The present study was conducted on total forty five (45) <em>Pati</em> duck of Assam. Ducks were divided into five groups: 0, 4, 16, 24, and 42 weeks. For histochemical parameters, tissue samples were preserved in deep freeze maintained at -80<sup>o</sup>C (except for PAS-alcian blue, where paraffin sections were utilized) immediately after collection. The preserved tissue samples were shifted directly to cryostat microtome maintained at -22<sup>o</sup>C. The frozen sections were cut at 7 &micro;m thickness and were collected on clean slides and were treated as per the method of Singh and Sulochana (1978).<br />
<br />
<strong>Result:</strong> Histochemical studies revealed that the reaction of Alkaline phosphatase enzyme was mildin Harderian land of <em>Pati</em> duck. The reaction of the acid phosphatase was absent. The Adenosine triphosphatase (ATPase) activity was observed moderate in all the age groups. The activity of non specific esterase was observed strong in all the age groups. The periodic acid-Schiff (PAS-Alcian Blue 2.5 pH) stain revealed positive reaction in all the age groups which indicated the presence of acid sulfated mucosubtances in the cells.</p>


<p>Histochemical Study of the Harderian Gland of Pati Duck of Assam</p>


<div><strong>Background:</strong> The agro-climatic condition of Assam is suitable for duck rearing. Duck rearing contributes a major part to uplift the socio-economic condition of the rural poor people of Assam as well as others states located in the coastal regions of India. The <em>Pati</em> duck (<em>Anasplatyrhynchos domesticus</em>) population constitutes a major indigenous non-descript economically important duck variety in the state of Assam. The Harderian gland acts as a part of the Head Associated Lymphoid Tissue (HALT) <a href="#olah_1992">Olah <em>et al</em>. (1992)</a> and provides local innate immunity to the upper respiratory system, to the eye and oral cavity. Since literature on the postnatal development of Harderian gland of <em>Pati</em> duck is scant, hence the present study was designed to establish the basic anatomical details on Harderian gland at different stages of postnatal development of Pati duck of Assam.&nbsp;<br />
<br />
<strong>Methods: </strong>The present study was conducted on total forty five (45) numbers <em>Pati </em>duck of Assam at different stages of postnatal development. The experimental birds were brought to the Department of Anatomy and Histology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-22 and was sacrificed according to the method of <a href="#gracy_1986">Gracy (1986)</a>. After slaughter, the birds were placed on a clean dissecting table and skin and fascia were reflected carefully without disturbing the other organs of the head region. The Harderian gland was collected by opening the orbital cavity. Thereafter, length, breadth and thickness of the Harderian gland of all age group were recorded with the help of the Vernier Callipers <a href="#mcCance_1974">(McCance, 1974)</a> and topographical location of the gland was observed. The weight of the Harderian gland of all age group was also recorded with the help of electronic balance.&nbsp;<br />
<br />
<strong>Result:</strong> The Harderian gland of <em>Pati </em>duck (<em>Anas platyrhynchos domesticus</em>) was located &nbsp;within the orbit. The gland was flat, oval and coma shaped with irregular border. The gland had two surfaces <em>i.e</em>. the parietal and visceral surfaces, two borders and two blunt poles. The parietal surface was found convex and attached to fascia covered by the nasal bones and interorbital septa. The visceral surface was concave and it was attached loosely to the eye ball with fascia. The lobes of the Harderian gland became more prominent with the advancement of the age. The gland was light pink in colour. The arterial blood and the venus drainage was by provided by the ophthalmic artery and vein, respectively. The slender branch of oculomotor nerve innervated the Harderian gland. The result reflected an ascending trend from 0 week age group to 42 week age group in regard to all the gross parameters. There were slight difference between left and right glands for all the gross parameters but such variations were not statistically significant (P&gt;0.05). Each lobe of the Harderian Gland of Pati duck (<em>Anas platyrhynchos domesticus</em>) had a single short duct which opened into the conjunctival sac at the base of the 3<sup>rd</sup> eyelid.&nbsp;</div>


<div>Post Natal Gross Anatomical Studies on the Harderian Gland of Pati Duck (<em>Anas platyrhynchos domesticus</em>) of Assam</div>


<div><strong>Background:</strong> The farmers are rearing duck in small scale in semi intensive system without investing more capital but it contributes a major part to uplift the socio-economic condition of the rural poor people of Assam. The <em>Pati</em> duck (<em>Anas platyrhynchos domesticus</em>) population constitutes a major indigenous non-descript economically important duck variety in the state of Assam. The Harderian gland acts as a part of the head associated lymphoid tissue (HALT) and provides local innate immunity to the upper respiratory system,&nbsp;to the eye and oral cavity. Since literature on histological study of Harderian gland of Pati duck is scant, hence the present study was designed to establish the basic histological details on Harderian gland at different stages of postnatal development of Pati duck of Assam.<br />
<br />
<strong>Methods:</strong> The present study was conducted on total forty five (45) numbers<em> Pati </em>duck of Assam at different stages of postnatal development. The experimental birds were brought to the Department of Anatomy and Histology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-22 and was sacrificed according to the method of Gracy (1986). For histological study the tissue samples from the Harderian gland of all the age group were fixed in 10% neutral buffered formalin solution and processed to prepare paraffin blocks as per the procedure described by Luna (1968). The paraffin blocks were sectioned in Shandon Finesse microtome in 5 &micro;m thickness and the sections were stained by different methods as described by Luna (1968).&nbsp;<br />
<br />
<strong>Result:</strong> The Harderian gland of <em>Pati</em> duck had a capsule, the thickness of the capsule of the Harderian gland was increased slightly along the advancement of the age. The capsular connective tissue penetrated the parenchyma of the Harderian gland in the form of septa. The collagen, reticular, elastic and nerve fibers were observed along with the capsule and as well as in the septa. The Harderian gland of the <em>Pati</em> duck was compound tubular gland. The columnar epithelial cells lined the tubules. There was no cortex and medulla in the gland and the tubular structure were uniformly distributed within the lobules. A central canal was present in the gland which converged to the duct of the gland. The lymphocytes, plasma cells were found in the intertubular connective tissue. The numbers or population of plasma cell and lymphocytes were accelerated by the advancement of age. The myoepithelial cells with spindle shaped nucleus were present near the basement membrane close to the secretary cells. The histology of the duct of the Harderian gland of <em>Pati</em> duck was like that of typical hollow tubular organs. There were few lymphatic nodules very distinctly present extended from the lamina propria to the muscle layer.</div>


<p>Histological Study of the Harderian Gland of <em>Pati</em> Duck (<em>Anas platyrhynchos domesticus</em>) of Assam during Postnatal Development</p>


<div><strong>Background: </strong>Skin is the largest organ of the body, accounting for 15-20% of the total body weight and acts as a barrier between the external and internal environment and maintain homeostasis.The sweat and sebaceous glands in dermis of skin play vital role in developing the adaptive ability to the heat stress. Besides this, the distribution pattern and number of these glands vary in different animals that may aid in identification of different species.<br />
<br />
<strong>Methods:</strong> The study was conducted on abdominal skin of 36 adult cattle, buffalo, horse, goat, pig and dog (six sample of each) collected from abattoir, Veterinary clinics and post-mortem hall of GADVASU, Ludhiana. After collection, the tissues were fixed in 10% neutral buffered formalin and processed for paraffin block preparation. The paraffin sections of 5-6 &micro;m were cut and stained with hematoxylin and eosin stain.&nbsp;<br />
<br />
<strong>Result: </strong>The study revealed that the sebaceous glands were multilobular, alveolar glands comprised of several layers of epithelial cells and were associated with hair follicles in all species studied. The number of sebaceous glands/mm<sup>2</sup> was significantly higher (p&le;0.05) in goat (1.60&plusmn; 0.11) than in pig (0.44&plusmn;0.06) whereas sebaceous gland diameter was significantly higher (p&le;0.05) in buffalo (109.83&plusmn;6.14 &micro;m) than in goat (61.16 &plusmn;2.42 &micro;m).The sweat glands were of saccular and simple coiled tubular type and most of them were associated with hair follicles. The number of sweat glands/mm<sup>2</sup> was the highest in horse (3.10 &plusmn; 0.24) and the least in buffalo (0.76 &plusmn;0.05). Sweat gland diameter was significantly higher (p&le;0.05) maximum in buffalo (123&plusmn;3.15 &micro;m) and minimum in goat (50.33 &plusmn;2.85 &micro;m) and the difference.</div>


<div>Comparative Study on Distribution of Sebaceous and Sweat Glands in Skin of Different Domestic Animals</div>


<div style="text-align:justify">The present study was carried out to observe the histochemical details of the lacrimal gland in ruminants. The lacrimal gland located at the dorsolateral aspect of the eyeball which helps to nourish the cornea. In the present study a strong PAS positive reaction were seen in the secretory units of lacrimal gland in cattle, sheep and goat whereas, few secretory units showed strong PAS positive reaction and few secretory units showed weak PAS positive reaction in buffalo. Few secretory units and few secretory cells in some secretory units showed positive reaction for Alcian blue at (pH 2.5) in cattle, buffalo, sheep and goat. Intralobular and interlobular lipids were observed in buffalo, sheep and goat.</div>

Comparative histochemical studies of lacrimal gland in Ruminants<br />&nbsp;

<div><strong>Background:</strong> The present study was conducted to measure the dimensions of the adrenal glands in apparently healthy dogs for obtaining reference values via ultrasonographic modality.<br />
&nbsp;</div>

<div><strong>Methods:</strong> This study was carried out on 18 apparently healthy dogs divided into three groups of six each <em>viz</em>., Group I, II and III. Ultrasonographic examination was performed in all the animals in lateral recumbency. Ultrasound images of adrenal glands were reported in the sagittal plane and different measurements of both the adrenal glands were determined.<br />
<br />
<strong>Result:</strong> Both the adrenal glands were longest in Group III and shortest in Group I. Similarly, the cranial pole diameter and caudal pole diameter was thickest in Group III and thinnest in Group I. The measurements recorded during this study can be used as reference values.</div>


<div>Ultrasonographic Reference Values of Different Dimensions of Adrenal Glands in Healthy Dogs</div>


<p style="text-align:justify">The histological and histochemical structure of lingual salivary glands in mole rat (Spalax leucodon) were studied using histochemical staining techniques to provide information of its salivary glands. A total of five adult mole rat (Spalax leucodon) were used as the material. It was observed that serous and mucous glands are placed in the root of the tongue. It was detected that although the mucous gland cells were rich in terms of AB pH 0.5, 1.0, 2.5 and AF (+) mucosubstance, the PAS and KOH/PAS mucosubstances showed very weak reaction, and this mucosubstances were present at a very less amount in serous gland cells. &nbsp;In the PAS/AB staining, it was found that the serous and mucous gland cells showing only AB or only PAS reaction and also AB AB pH 2.5 (+) cells were found. The same findings were observed in serous glands by AF/AB staining. Consequently, the present study demonstrated characteristic features of the lingual salivary glands of the mole rat, and it revealed histological and histochemical data both in accordance with and different from that for the lingual salivary glands of mammals and other species.</p>


<p>Histological and histochemical structure of lingual salivary&nbsp;glands in mole rat (Spalax leucodon)</p>


<div><strong>Background:</strong> In developing countries goat rearing is the sustainable source of income for marginal farmers. The goat milk contains lower fat per cent (3.5%) as compared to cow (4.1%) and buffalo milk (7.4%), with smaller and homogenous fat globules. It is suitable for the persons with poor digestibility of cow milk and infants having mother milk intolerance. To improve the milk production it is important to understand the mammary gland pattern during the different phases of lactation. The present study aimed at analyzing these changes by histological and histochemical observations. The mammary gland is composed of parenchyma containing acini and stroma including the ductual system. These components change during the lactation cycle.&nbsp;<br />
<br />
<strong>Methods:</strong> The present study was conducted on 24 goats, eighteen in lactating stage where as six from nonlactating stage. The mammary glands were collected from local abattoir with known history of stage of lactation and divided into three groups as early lactation (2-4 weeks), mid lactation (5-6 weeks) and late lactation (&gt; 6 weeks). The histological and histochemical studies were performed during the different stages of lactation and in non lactating stage to observe the morphological and morphometrical changes along with the presence and absence of different components.&nbsp;<br />
<br />
<strong>Result: </strong>The lobules of the mammary gland were polygonal, triangular, oval or elongated in shape during early lactation stage. Approximately all the alveoli observed in early lactation were filled with variable quantity of eosinophilic substance and appeared foamy, due to presence of variable size of fat vacuoles. In mid lactation the lobules became highly irregular. The long and short diameter of lobules was 1041.69 &micro;m and 563.93 &micro;m, respectively. The intralobular stroma was inconspicuous hence alveolar wall appeared to touch each other. In late lactation lobules became shorter in size. The large alveoli showed folded and collapsed appearance. In nonlactating stage well defined alveoli, clusters of desquamated cells were seen and degenerated alveoli were also observed. These histomorphological changes in the secretory unit of the mammary gland reflect the lactation yield and milk composition during different stages of lactation.&nbsp;</div>


Histochemical changes during development of Harderian gland in chicken

Macro and Micro anatomical study of Harderian Gland of Duck and Fowl

Histochemical Study of the Harderian Gland of Pati Duck of Assam

Post Natal Gross Anatomical Studies on the Harderian Gland of Pati Duck (Anas platyrhynchos domesticus) of Assam

Histological Study of the Harderian Gland of Pati Duck (Anas platyrhynchos domesticus) of Assam during Postnatal Development

Comparative Study on Distribution of Sebaceous and Sweat Glands in Skin of Different Domestic Animals

Comparative histochemical studies of lacrimal gland in Ruminants

Ultrasonographic Reference Values of Different Dimensions of Adrenal Glands in Healthy Dogs

Histological and histochemical structure of lingual salivary glands in mole rat (Spalax leucodon)

Histomorphological Changes in the Mammary Gland of Local Indian Goat during Lactation Cycle