RESUMEN
Background: the tongue, which plays a very important role in food intake by vertebrates, exhibits significant morphological variations that appear to represent adaptation to the current environmental conditions of each respective habitat
Objectives: the aim of the present investigation was to investigate lingual structure in adult budgerigar
Methods: tongues of 12 adult budgerigars were used in this investigation. Samples of the apex, body and root of the tongues were studied using light and electron microscopy
Results: the tongue in budgerigar is about 5 mm in length. The deep concave rostral portion of the lingual apex is devoid of any glandular structure and is continuous with a semicircular caudal portion. The caudal portion of the lingual apex is divided into two symmetrical halves by a median longitudinal fissure. The rostral part of the lingual corpus is distinctly divided by fissures of varying depth into many irregular raised areas with different sizes. Several large caudally directed conical papillae are situated on the posterior end of the lingual corpus and along the thick border region between the lingual body and root. There are also some giant conical papillae on the laryngeal mound. According to their positions, the PAS-positive compound tubuloalveolar salivary glands can be classified as dorsal and dorsolateral salivary glands. The dorsal lingual salivary glands are situated beneath the dorsal lingual epithelium. They extended from the caudal end of the fissure on the caudal lingual apex to the front of the laryngeal cleft. The dorsolateral salivary glands on each side extend from the beginning of the body of the tongue to the level of the laryngeal cleft. The ventral side of the tongue is devoid of any glandular structure. Neither the morphology nor the dimensions of the tongue show sex-specific differences
Conclusions: lingual structure shows considerable differences in budgerigars in comparison to other birds studied so far
RESUMEN
The aim of the present study was to investigate the light and electron microscopic structure of the tongue in White-eared bulbul [Pycnonotus leucotis]. Six adult White-eared bulbul [3 males and 3 females] in Shahrekord district were used in the investigation. Samples of the apex, body and root of the tongue were prepared routinely for light and electron microscopic study. Results showed that the tongue is characterized by an elongated triangular format. At a point, approximately 2/3 the length of the lingual corpus there is a distinct depression, separating the caudal one-third of the lingual corpus from its rostral two-third. On the dorsal surface of the apex and body of the tongue, a median groove is found. A unique feature of the tongue in White-eared bulbul is the presence of many fine overlapping needle-shaped processes at both lateral sides of the anterior lingual apex. A single row of large conical papillae is observed symmetrically in the marginal region between the body and root of the tongue. The mucosa of the tongue is covered with a thick stratified squamous epithelium, which is cornified only on the ventral surface of the apex. The periodic acid schiff [PAS] positive lingual salivary glands can be classified as dorsolateral and mediodorsal salivary glands. The compound tubular dorsolateral glands extend from the apex of the tongue to both sides of the laryngeal cleft. The compound tubulo-alveolar mediodorsal glands are found in the lingual root. At electron microscopic level, many fine openings of these glands are scattered throughout the dorsal surface of the lingual root. Neither the morphology nor the dimensions of the tongue show sex-specific differences
RESUMEN
The aim of this project was to study the influence of the sex and age factors on the wall structure of the esophagus of the dog. Eighteen mixed breed dogs, [9 male and 9 female] in three age groups [3 neonate, 3 sexually mature and 3 old] were used. Animals were euthanized and after removing the whole esophagus, full thickness transverse sections were cut from the proximal, middle and distal parts. Microscopic sections of these samples were prepared and then examined for minimum and maximum thicknesses of the tunicae mucosa, submucosa and muscularis. Due to the absence of lamina muscularis mucosa in the proximal part of canine esophagus, the tunicae mucosa and submucosa in this region were collectively named tunica mucosa-submucosa. Results obtained from this study showed that there is a large increase in the thickness of tunica mucosa-submucosa and mucosa, from neonatal to sexually mature stages followed by a smaller increase between sexually mature and old stages in both sexes. We also found that the thickness of the mucosal layer is greater in distal part of esophagus than its middle part in all three age groups and both sexes. The thickness of tunica submucosa of the middle and distal parts and tunica muscularis of the proximal, middle and distal parts of esophagus showed a large increase between neonatal and sexually mature stages followed by a smaller decrease between sexually mature and old stages in both sexes. Also we found that the thickness of the submucosal layer is greater in distal part of esophagus than its middle part in all three age groups and both sexes. The thickness of the muscular layer showed a progressive increase from proximal part to the distal part in all age groups and both sexes. The differences between the two sexes in the thickness of esophageal layers do not follow a constant pattern