Histological and histochemical changes of the broiler,s harderian gland following some occularly inoculated vaccines /
المؤلف
El-Genaidy, Hala Mohamed Ali.
هيئة الاعداد
باحث / هالة محمد على الجنيدى
مشرف / عبد الحميد كامل عثمان
مشرف / اسيا محمد الصاوى
مناقش / سمير محمد نوار
مشرف / ابراهيم عبد الرحيم
الموضوع
veterinary medicine. histology. Avian lymphatic system performs a role similar to that or mammals <br>III being responsible for avian immunity In birds. lymphoid tissue is <br>considered to be either primary (central) or secondary (peripheral). The <br>primary tissue comprises the cloacal bursa (bursa of Fabricius) which is <br>unique to birds, and the thymus. Secondary lymphoid tissue consists of <br>the spleen, bone marrow, lymphoid modules ill the wall of the lymphatic <br>vessels and form large subepithelial aggregates in the alimcntarv and <br>respiratory systems. Many tissues and organs also contain small lymphoid <br>aggregates, e.g. In eye orbit, the gland of nictitating membrane <br>”Harderian gland or the gland of Harder” (Beres field, /977) <br>The central lymphoid organs are believed to be the primary sitc~ <br>where lymphocytes were developed and would subsequently control the <br>development and the function of other peripheral lymphoid organs (Glick, <br>1956). <br>The gland of Harder was firstlv described by Johann Jakob. I larder. <br>,I pirysrcian and naturalist so It I::i called the gland or Harder or llardcnan <br>gland (Kennedy, /970). <br>The Harderian gland is found in the orbit of most vertebrates <br>except fish. It is prominent in amphibians, birds and reptiles whereas the <br>lacrimal gland is ofteu poorly developed or absent. It is relatively large ill <br>the fowl, being much larger than the lacrimal gland iwigln et al., /971) <br>( I )
الفهرس 
Introduction
