Post-ovulatory follicle in the ovary of a pigeon (HE)
After ovulation, the follicle shrinks. The remaining follicle wall (both stratum granulosum and theca follicularis) thickens. Vacuolar cells are formed by accumulation of fat in their cytoplasm and come loose to gradually fill the follicular cavity. The nuclei of these vacuolated cells become pycnotic and the cells regress, causing the regression of the whole follicular wall which will get reabsorbed in the mass of the cortical stroma. In contrast to mammals, no corpus luteum is formed.
See also: endocrinum.