Fig. 1

Photomicrograph of the sheep ovary during the follicular phase. A Ovarian cortex showing preovulatory follicles (POF) and large antral follicles (LAF). B Ovarian cortex showing growing follicles (GF), small antral follicles (SAF) and preovulatory follicles (POF). C Ovarian cortex showing ovarian surface epithelium (S) which formed of single layers of flattened epithelial cells, dense irregular connective tissue of tunica albugenia (TA) and primordial follicles (PF). D Ovarian cortex showing growing follicles (GF), atretic follicles (AF) and interstitial glands (ISG). E The wall of preovulatory follicles showing dissociated granulosa cells (G), thin basement membrane (arrow), theca interna (TI) and theca externa (TE). F Showing atretic antral follicle (AAF). G Showing corpus albicans (CA). J Showing the structure of the corpus albicans which composed of dense irregular connective tissue (CT) and some blood vessels (BV). K Showing the ovarian medulla formed of loose connective tissue (LCT) and numerous blood vessels (BV). Original magnification; A & B: X12.5, scale bar = 1mm, C & J: X200, scale bar = 100 µm, D, F & K: X100, scale bar = 200 µm, E: X 400, scale bar = 50 µm, G: X 40, scale bar = 500 µm, haematoxylin and eosin stain