الفهرس | Only 14 pages are availabe for public view |
Abstract This study is made in embryos of guinea pig and chick. The guinea pigs brought and paired overnight. On next day examination of the females for presence of vaginal plug or spermatozoa in vaginal smear. Then the females were divided into five age groups 7,10,13,17 20 day of gestation. The females of each group are isolated in separated cage. At the survival day of each group the females were brought then aneasthesied, and the abdomen and uterus were opened and embryos got out. Fertilized eggs brought and divided into five age groups 7,10,13,17,20 day of incubation. Embryos got out from the egg. Paraffin sections were prepared and stained with haematoxyllin and eosine. In guinea the pig the epithelium at 7 th and 10 the day of gestation was simple columnar. Then at 13 th day of gestation the epithelium was pseudostratified columnar and some cells showed brush border. At 17 th day of gestation the basal cells started to appear. At 20 th day of gestation the epithelium was pseudostratified columnar with ciliated columnar, non ciliated columnar and basal cells. However non-of others types of cells appeared as goblet cells leucocyte, lymphocyte or kulchitsky cells. But in the chick the developing epithelium of the trachea appeared at 7th, 10th, 13 th day of incubation as many layers of undifferentiated cells. At 17 th day of incubation the epithelium became pseudostratified columnar with columnar cells and basal cells. At 20 th day of incubation the epithelium became apparently well differentiated with ciliated columnar, non ciliated columnar, basal and goblet cells. |