Morphological Aspects and Differences Between Segments of the Oviduct in Chicken

Abstract

Although the gross morphology and structure of the oviduct is similar in the entire organ, there are morphological, structural, histochemical and ultrastructural differences between the segments, particular to their function. The present study highlights the anatomical and structural differences between the five segments of the oviduct: infundibulum, magnum, isthmus, uterus and vagina. A number of 30 Lohmann Brown chickens aged between 19 and 50 weeks were used for this research. Samples were taken from each segment and fixed in 4% buffered formalin and Bouin; embedded in paraffin, cut at 5 µm and stained PAS, H-E, Novelli, Masson, Van Gieson and Von Kossa. The infundibulum presents two areas that have a distinct morphology and structure. The funnel has very thin walls with small mucosa folds while the infundibular neck is thicker and presents small tubular glands in the lamina propria of the mucosa. Magnum has the largest mucosa folds that consist of tubular glands which elaborate the albumen. The morphology of the next segment, isthmus, is similar to that of the magnum, but the folds are lower and thinner. In this segment, the secretion takes a particular shape as filaments that form the shell membranes. The uterus is very well distinguished from the other segments based on its' morphology that has a sack shape. The mucosa folds are leaf-shaped and the musculosa is very well developed. The vagina has numerous thin and tall primary folds with secondary and tertiary folding, and the tubular glands from this segment are missing. The smooth muscular cells are grouped in bundles, surrounded by connective tissue. We described numerous differences in the morphology, structure and histochemistry of the five oviduct segments in chicken.