Prenatal Development of Pelvic Urethra in Goat (Capra hircus)

The study was conducted on the embryo/foeti of goat from 0-150 days of gestation, divided into group I (0-30 days), group II (31-60 days), group III (61-90 days), group IV (91-120 days) and group V (121-150 days of gestation). In group I whole embryo was processed and serial sections were cut whereas, in rest of the groups, pelvic urethra was dissected out and the tissues from the representative areas were used for the study. Grossly, on 49.33 days of gestation the pelvic urethra was present in the form of smooth cylindrical tube, approximately 4mm in length. The primordial of vesicular gland and bulbourethral gland appeared on 52 days of gestation at the junction of neck of urinary bladder with pelvic urethra and at the junction of pelvic and penile urethra respectively. The length, width, height and circumference of pelvic urethra increased with increased in gestation period, however the length (7 times) and circumference (9 times) increased maximum from group II to group V. The morphometrical parameters (length, width, height and circumference) of pelvic urethra were significantly correlated with the age and weight of foetus throughout gestation period. The colliculus seminalis, which was present in the form of ridge on 72 days of gestation, became distinct on 75 days of gestation. Histologically, on 28 days of gestation, the urogenital sinus was present as a cleft with in the cluster of cells. On 55 days of gestation, the process of luminization started with in the wall of pelvic urethra, which started first in its caudal part and proceeded cranially. All the four layers (Tunica mucosa, submucosa, muscularis and adventitia) were distinct. The lumen was lined with 3-4 layers of stratified epitheliumin group II but in group III on 70 days of gestation and beyond this distinct transitional epithelium was present. The formation of cavernous spaces started at 59 days of gestation. Their number and size increased with increased in gestation period. The thickness of submucosa, muscularis and adventitia increased with the advancement in the age of foetus, whereas the height of epithelium decreased.