Gross anatomy and mineralization of larynx, trachea and syrinx in gray heron (Ardea cinerea)

Abstract

This study aims to determine the normal anatomical features of the larynx, trachea, and syrinx of the heron birds and to identify the cartilage and mineralized areas with red Alcian blue staining. Three adult heron birds’ larynx, trachea, and syrinx were used as materials in the study. Sex of the birds was neglected. With the staining of alizarin red Alcian blue, cartilage tissues were blue, and mineralized areas with calcium accumulation were red. In the macroscopic examination, mons laryngealis was seen on the caudal side of the tongue on the larynx under a stereomicroscope. It was observed that there was a thin and long-looking glottis on mons laryngealis. Larynx cranialis was observed to consist of two cartilago arytenoidea and one cartilago cricoidea in alizarin red staining. Trachea was found to consist of fully mineralized rings, except for the first and incomplete mineralized cartilago trachealis. Trachea rings were found to form a complete ring except for the first cartilago trachealis. Diameters of the rings differed regionally throughout for the trachea. It was determined that the widths of the trachea rings were approximately the same size except the first one. Syrinx was found to be the tracheobronchial type, which is the typical simple type syrinx. The four rings that make up the tracheabrochial syrinx were seen to merge. This is the first study showed the detailed anatomical description of larynx trachea and syrinx belonging to heron birds with alizarin red Alcian blue staining.