Prenatal development of rectal patch in large intestine of goats

Abstract

Prenatal development of rectal patch was studied in 30 goat fetuses ranging from 1.4 cm CRL (24 days of gestation) to 38.0 cm CRI (Crown ramp length). Rectal patch first appeared in goat foetuses by 60 days of gestational age as a continuous band of small to medium–sized lymphocytes in the lamina propria of rectum. During fourth month of gestation, the primordia differentiated into large lymphoid nodules which had an oval basal portion and a pyramidal apical portion, which formed a dome-like structure within the intestinal ridges below the surface epithelium and was surrounded by an irregular capsule. During fifth month, an increase in the number and size of the lymphoid nodules and primordial dome region was noticed. The lymphoid nodules were histologically mature with a prominent germinal center, its corona, a wide dome area and an internodular area with few high endothelial venules. The rectal patch was histologically mature at birth with both primary and secondary nodules in it.