MORPHOLOGY OF THE CAECUM IN LABORATORY ANIMALS IN HEALTH: SPECIES COMPARISON

In recent decades, the prevalence of gastrointestinal diseases has increased thus posing the immediate, both therapeutic and surgical treatment. It brings forth a problem of searching new and improving existing approaches and techniques for correcting the above-mentioned diseases. Preclinical studies in this area are conducted exclusively on laboratory animals and peculiarities of the morphological features of their organs are of great importance when comparing with the human morphology. The methodology used in the study included histological, morphometric and statistical techniques; biopsy samples of caecum taken from 5 rabbits were investigated. We assessed the correctness of the trait distribution by each of the variations, the mean values for each trait studied, standard errors and standard deviations. The significance of the difference of values between independent micrometric values in the normal trait distribution was determined by Student's criterion. The paper describes the main morphological characteristics of the caecum in rabbits and compared the findings obtained with similar structures of the human caecum. The caecum of rabbits, as of humans, has four layers: mucous, submucosal, muscular and serous. The mucous membrane consists of the epithelial layer located on the basement membrane and the muscular plate and contains cellular elements. The submucosa is composed of loose fibrous connective tissue, which contains collagen and reticular fibres, elements of diffuse lymphoid tissue, blood vessels, and nerve endings. The muscular and serous membranes are quite similar to the human caecum. Thus, the optic light microscopy has demonstrated the morphology of the caecum in rabbits is similar to that in the human caecum.