title: Macroscopic anatomy of the lower respiratory system in a nocturnal burrowing rodent: African giant pouched rat (Cricetomys gambianus, Waterhouse 1840).
abstract: Cricetomys gambianus is a rat that lives principally in burrows, coming out at night in search of food. The design and structure of the lower respiratory system reflects its oxygen and metabolic demand which can be attributed to its habitat. A morphological and morphometric investigation of its lower respiratory system was undertaken to document the normal anatomical features and assess its morpho-functional paradigm. Specifically, an anatomical detail of the lungs and conductive airway was described, the structures being elucidated by dissection and radiography. Evaluation of dissected specimens showed that tracheal cartilages ranged from 21 to 33 rings with an average of 25.5. They exhibited a random pattern of anastomoses between adjacent rings. Transverse diameters of the principal bronchus in the male and female rats were 3.767 and 3.759 mm respectively. The right lung consisted of four lobes while the left lung was not lobed. Bronchogram revealed that lung lobation corresponded with bronchial tree division. Inter-lobar fissures were absent on the right lung except for the ventral boarder separating the cranial lobe from the caudal lobe. The entire lungs provided stability to the heart in situ, through the cardiac notch. This study also included correlation analysis of the dimensions, weights and volumes of the lower respiratory organs with the nose-rump length and body weight of 18 African giant pouched rats of both sexes. The relationship of the anatomy of the lower respiratory system of the rodent to the oxygen tension in their burrow and to their energy utilization is discussed.
authors.affiliation: Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Ahmadu Bello University, Samaru, Zaria, Kaduna State, Nigeria. writechikera@yahoo.com
authors.forename: C S
authors.initials: CS
authors.lastname: Ibe
authors.forename: S O
authors.initials: SO
authors.lastname: Salami
authors.forename: B I
authors.initials: BI
authors.lastname: Onyeanusi
mesh_terms: D000818:Animals; D001980:Bronchi / Q000033:anatomy & histology*; D005260:Female; D006321:Heart / Q000033:anatomy & histology; D008168:Lung / Q000033:anatomy & histology*; D008176:Lung Volume Measurements; D008297:Male; D009929:Organ Size; D012123:Pulmonary Ventilation / Q000502:physiology; D051381:Rats / Q000033:anatomy & histology*; D014132:Trachea / Q000033:anatomy & histology*