Posthatching Development of Vascularization,Arteriovenous Anastomoses and Seromucous Glands in the Avian Nasal Mucosa

The development of blood vessels and growth of different tissue compartments in the avian nasal mucosa were studied in chickens from hatching to 5 months of age. The vascularity of the rostral and middle nasal conchae increased about 4-fold, while there was a progressive decrease in the relative size of the epithelium and connective tissue compartments, during the maturation period. Arteriovenous anastomoses (AVAs) were present already at hatching and their density increased 3-fold during the second week of posthatching development. The seromucous glands form by a process of invagination of the epithelium, which occurs predominantly during the first week after hatching. The glands continue to grow in size and an increasing fraction of the cells becomes mucous-secreting. The observations are discussed in relation to the role of the nasal mucosa in temperature regulation and conditioning of the inhaled air.