解剖学と生理学: 現在の研究
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概要

Histomorphometric Study of the Prenatal Development of the Circumvallate Papillae of One-Humped Camel (Camelus Dromedarius)

Bello A, Alimi OO, Sonfada ML, Umaru MA, Onu JE, Onyeanusi BI and Shehu SA

This study aimed at investigating the prenatal development of camel circumvallates papillae using standard histomorphometric methods. In the experiment, fifteen Camelus Dromedarius foetuses obtained from Sokoto metropolitan abattoir at different gestational ages were used for the study. The foetuses were weighed and grouped according to their gestational ages which were estimated using their crown-vertebral-rump length. From the fifteen (15) samples used for the study, five (5) belongs to the first trimester, five (5) from the second trimester and five (5) belongs to the third trimester. A total of ten (10) foetuses were males and five (5) were females. Grossly, in all the stages of development, the tongues were observed to be elongated, with flat surfaces and rounded at the apices. At first trimester, the tongues were seen as smooth muscle mass, with almost uniform width and thickness throughout the length. They were uniformly pinkish, no pigmentation and no visual evidence of lingual papillae. At second trimester, the tongues were observed to have taken the normal shape of an adult tongue with variable size and shape of lingual papillae; tapering rostrally from the root to the apex. Biometrically, the weight of the foetuses were found to be 0.18 ± 0.05 to 21.70 ± 7.28 kg from the first trimester to second trimester, the crown–vertebral–rump– length were found to be 15.75 ± 4.42 to 94.00 ± 2.83 cm from the first trimester to the third trimester, weight of the head were found to be 25.05 ± 15.17 to 1120.00 ± 14.14 g and weight of the tongues were found to be 0.79 ± 0.22 to 116.25 ± 11.49 g from first trimester to third trimester. Histological observations showed that the circumvallate papillae were generally lined with keratinised stratified squamous epithelium, which was composed by basal, spinosum, granulosum and corneum layers. Lingual glands are located in the deeper parts of the papillae. The surface epithelium was less keratinised compared to that of the surrounding surface except the peripheral parts of the papilla. Dermal inter-digitations of variable sizes into the epidermis were observed along the whole surface. Few taste buds were observed along the medial papillary wall epithelium of the small-sized papillae.