The ostrich hyobranchial apparatus consists of the centrally positioned paraglossalia and basiurohyale and paired caudo-lateral elements (horns), each consisting of the ceratobranchiale and epibranchiale. The paraglossalia lie within the tongue parenchyma and consist of paired, flat, caudo-laterally directed cartilages joined rostrally. The basiurohyale forms a single dorso-ventrally flattened unit composed of an octagonal-shaped body from which extend rostral (the rostral process) and caudal (the urohyale) projections. The laryngeal skeleton consists of cricoid, procricoid and paired arytenoid cartilages. The large ring-shaped cricoid cartilage displays a body and paired wings which articulate with each other and with the procricoid. The blunt, ossified, rostral projection of the cricoid and the scalloped nature of the arytenoid cartilages are unique to the ostrich. The procricoid is a single structure which links the paired arytenoids and wings of the cricoid. The hyobranchial apparatus is firmly attached to the tongue parenchyma and to the larynx and proximal trachea. In contrast to previous reports in this species, the horns of the hyobranchial apparatus are not related to the skull. Ossification of the body of the basihyale, the ceratobranchials and the rostral process and body of the cricoid cartilage of the larynx lends stability to these structures.

Most descriptions of the ostrich oropharynx and oesophagus are superficial and supply little meaningful morphological data. The aim of this investigation is describe the ostrich oropharingeal cavity, in order to supply the deficiency of macroscopic data about this important animal. Five heads of 12 to 14-month-old ostriches of either sex were anatomically dissected to expose the oropharynx. The ostrich oropharynx was "bell-shaped" composed by the maxillary and mandibular ramphoteca. The roof and floor presented two distinct regions different in colour of the mucosa. The rostral region was pale pink contrasting to creamy-pink coloured caudal region. The median longitudinal ridge extended rostrally from the apex of the choana to the tip of the beak in the roof and it is clearly more prominent and rigid than the homolog in the floor that appeared thin and stretched rostrally, continuing caudally surrounding the tongue and the laryngeal mound eventually merging with the oesophageal mucosa. The floor was formed by the interramal region, tongue and laryngeal mound containing shield-shaped glottis. It can be concluded that the present study, in addition to confirming the basic features of the oropharynx previously described for the ostrich, clarified the contradictory information presented in the literature and also provided new, unreported morphological data, some of which may be important when studying nutrition and health in these birds. RESUMO.-[Características macroscópicas da cavidade orofaríngea de avestruz (Struthio camelus).]Os estudos já realizados sobre a cavidade orofaríngea da avestruz são escassos e não elucidam completamente sua morfologia. O objetivo desse estudo foi descrever macroscopicamente a cavidade orofaríngea de avestruzes com o intuito de suprir a deficiência de informação nesta espé-cie. Foram utilizadas 5 cabeças de avestruzes com doze a quatorze meses de idade dissecadas seguindo padrões anatômicos de modo a expor a orofaringe. A orofaringe de avestruzes tem formato de sino e é composta pelas ranfotecas maxilar e mandibular. O teto e o assoalho apresentavam duas regiões distintas diferindo quanto à coloração da mucosa. A porção mais rostral era de coloração rosa pálida contrastando com a coloração mais fortemente rosada da porção mais caudal. A ruga palatina mediana estendia-se rostralmente do ápice da coana até a ponta do bico. No teto esta era mais proeminente e rígida que a do assoalho que se apresentava delgada e se estendia ao longo da porção rostral da região interramal, continuando caudalmente ao redor da coana e laringe e estendendo-se até o esôfago. O assoalho estava formado pela região interramal, língua e uma laringe com uma glote em forma de escudo. Pode-se concluir o presente estudo, além de Pesq. Vet. Bras. 31(6):543-550, junho 2011Catarina Tivane et al. 544 confirmar as características básicas da orofaringe da avestruz previamente descritas, clarificam a informação contraditória presente na literatura e também novas informações morfológicas não previamente descritas são d...

Pesq. Vet. Bras. 32(7):681-686, julho 2012 681 RESUMO.-As emas são aves que pertencem ao grupo das ratitas e juntamente com os avestruzes e emus, são as maiores aves vivas na atualidade. Neste trabalho estudou-se os aspectos macroscópicos do aparelho digestório de emas Rheas are birds belonging to the ratites group and, among ostriches and emus, are the largest birds currently alive. In this work we studied the macroscopic aspects of rheas' digestive tract in order to provide important information to a better understanding of these birds' eating habits as well their anatomy. Twenty young animals aging between two and six months from the Centre for Wild Animals Multiplication (Cemas, scientiϐic breeding license form Ibama no.1478912) were used. After dissection it was observed that their tongue was small and presented a rhomboid form, being disposed on the oral cavity ϐloor, and inserted in its base by a frenulum. The esophagus was a rectilinear tube with elastic aspect and longitudinal elastic ϐibers, without dilation, which gives it an absence of crop. The proventriculus presented a fusiform form and the gastric ventricle showed and slightly oval form when ϐilled, and was internally coated with a thick gastric cuticle. The small intestine was composed of three distinct regions: duodenum, jejunum and ileum. The duodenum had a light gray color and showed a "U" curved shaped. The jejunum was dark green, long and composed of several short loops arranged above each other. The ileum had a gray color and was connected with the jejunum. In ventral line to the rectum and cloaca, the ileum extended cranially, dorsally to the ascending duodenum. The large intestine was composed of two caeca, one right and one left, and colon-rectum and ileum were continuous with the cloaca. The structures of the rhea digestive tract resemble those described in the literature regarding to its shape and topography, even though rhea's caeca are well developed and relatively long.INDEX TERMS: Rhea americana americana, anatomy, digestive apparatus, birds.