Browsing by Subject "Ontogeny"

Now showing 1 - 3 of 3
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    Comparative anatomy of the nasal cavity in the common dolphin Delphinus delphis L., striped dolphin Stenella coeruleoalba M. and pilot whale Globicephala melas T.: a developmental study
    (MDPI, 2021-02-08) Ríos y Loshuertos, Alvaro García de los; Soler Laguía, Marta; Arencibia Espinosa, Alberto; López Fernández, Alfredo; Covelo Figueiredo, Pablo; Martínez Gomariz, Francisco; Sánchez Collado, Cayetano; García Carrillo, Nuria; Ramírez Zarzosa, Gregorio José; Anatomía y Anatomía Patológica Comparada; Facultad de Veterinaria
    Our goal was to analyze the main anatomical structures of the dolphin external nose and nasal cavity from fetal developmental stages to adult. Endoscopy was used to study the common development of the external nose and the melon, and nasal mucosa. Magnetic resonance imaging (MRI) and anatomical sections were correlated with anatomical sections. Computed tomography (CT) was used to generate 3D reconstructions of the nasal bones and nasal cavities to study its development. Dissections, histological and pathological studies were carried out on the nasal mucosa to understand its function. These results were compared with the horse. Endoscopy showed an external nose with two lips and the upper lip is divided by a groove due to the nasal septum and an obstruction of right nasal cavity was diagnosed in a newborn. Two diverticula (air sacs) were found in the nasal vestibule and an incisive recess (premaxillary sac) in the nasal cavity. These findings were corroborated by 3D reconstructions of the nasal cavities, MRI, anatomical sections and dissections. The presphenoid and ethmoid bones were fused at early stages of fetal development. The ethmoid is the last bone to ossify in the nasal cavity.
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    Endoscopic study of the oral and pharyngeal cavities in the Common dolphin, Striped dolphin, Risso’s dolphin, Harbour porpoise and Pilot whale: reinforced with other diagnostic and anatomic techniques
    (MDPI, 2021-05-22) García de los Ríos y Loshuertos, Álvaro; Soler Laguía, Marta; Arencibia Espinosa, Alberto; Martínez Gomariz, Francisco; Sánchez Collado, Cayetano; López Fernández, Alfredo; Gil Cano, Francisco; Seva Alcaraz, Juan; Ramírez Zarzosa, Gregorio José; Anatomía y Anatomía Patológica Comparadas
    In this work, the fetal and newborn anatomical structures of the dolphin oropharyngeal cavities were studied. The main technique used was endoscopy, as these cavities are narrow tubular spaces and the oral cavity is difficult to photograph without moving the specimen. The endoscope was used to study the mucosal features of the oral and pharyngeal cavities. Two pharyngeal diverticula of the auditory tubes were discovered on either side of the choanae and larynx. These spaces begin close to the musculotubaric channel of the middle ear, are linked to the pterygopalatine recesses (pterygoid sinus) and they extend to the maxillopalatine fossa. Magnetic Resonance Imaging (MRI), osteological analysis, sectional anatomy, dissections, and histology were also used to better understand the function of the pharyngeal diverticula of the auditory tubes. These data were then compared with the horse’s pharyngeal diverticula of the auditory tubes. The histology revealed that a vascular plexus inside these diverticula could help to expel the air from this space to the nasopharynx. In the oral cavity, teeth remain inside the alveolus and covered by gums. The marginal papillae of the tongue differ in extension depending on the fetal specimen studied. The histology reveals that the incisive papilla is vestigial and contain abundant innervation. No ducts were observed inside lateral sublingual folds in the oral cavity proper and caruncles were not seen in the prefrenular space.
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    The distribution and ontogeny of gastrin/CCK-, somatostatin- and neurotensin-immunoreactive cells in the gastrointestinal tract of the chicken
    (Murcia : F. Hernández, 1989) Alison, B. G.
    The distribution and time of appearance of cells with gastrin1CCK-, neurotensin- and somatostatinlike immunoreactivity were studied in samples from eight regions of the gastrointestinal tract of chick embryos from 11 days of incubation to hatching. No immunoreactive cells were found in any region at 11 days of incubation. Somatostatin- and neurotensinimmunoreactive cells appeared for the first time in the proventriculus, pyloric region and duodenum at 12 days of incubation with cells immunoreactive for neurotensin occurring in the rectum at the same stage. GastrinICCKimmunoreactive cells were detected in the small intestine first at 14 days and in the pyloric region two days later. Cells immunoreactive for somatostatin and neurotensin appeared in the upper and lower ileum at 14 days of incubation for the first time; neurotensin-immunoreactive cells, present in the caecum at 14 and 16 days, were rare. Cells of al1 three types were plentiful in the pyloric region by 17E days of incubation. No immunoreactive cells were detected in the gizzard at any stage studied. Endocrine cells were present in the relatively undifferentiated surface epithelium which occurs throughout the gastrointestinal tract of chick embryos at 12 days of incubation. Thereafter cells of al1 three types were detected in the glandular epithelium at or very soon after morphogenesis and differentiation of the latter had occurred.