Abstract
An experiment on in vivo effects of tobacco smoking injury to trachea in mice model was carried out at the Department of Anatomy and Histology, Bangladesh Agricultural University during July 2012 to January 2014 to investigate the harmful effects of smoking on trachea of mice. Fifteen white Swiss Albino (Mus muculus) male mice (collected from ICDDRB) at 42 days were grouped (each of which has 5 mice) as control group (C), cigarette fume treated group (CF) and cigarette root treated group (CR). Control group was under normal food and water, for fume treated group (CF); fume of 5 cigarettes were given for 5 minutes 3 times daily at one hour interval and five cigarette roots were mixed with half liter water and supplied ad libitum to root treated group (CR). Both these two groups were supplied with normal feed and water ad libitum. Total experimental tenure was 4 weeks. After 4 weeks all mice were killed and samples were collected from various systems of the body and were preserved, processed for slides and stained (H and E) for histo-pathological investigation. All parameters are normal in control animals. Shape and color change were found in the trachea of fume and root treated groups. The weight, length and width of trachea were reduced. Histo morphological changes such as epithelial degeneration in the upper airway like trachea were found in all treated groups. The mucosal lining of trachea was severely affected in all treated groups. The important changes are erosions and desquamations of epithelial cells as well as loss of mucosal lining, Shortening and amalgamation with loss of cilia, an increase in number of goblet cells with their active secretion were found. Lymphocytic infiltration was also noted in this study.

Key words: Cigarette, smoking, tracheal morphology, histopathology, Swiss Albino mice