2. Diagrammatic representation of the steroid biosynthetic pathways
Diagrammatic representation of the steroid biosynthetic pathways. Ovarian sex steroid pathways are in red. P450c, cytochrome P450; LH, luteinizing hormone; DH, hydroxylase; DHEA, dehydroepiandrosterone; DOC, desoxycorticosterone; cmpd B, corticosterone; cmpd S, II-desoxycortisol

3. Late secretory phase endometrium
Late secretory phase endometrium. Note the tortuous, saw-toothed appearance of the endometrial glands with secretions in the lumens. The stroma is edematous and necrotic during this stage leading to sloughing of the endometrium at the time of menstruation

4. Schematic representation of the sequence of events occurring in the ovary during a complete follicular cycle.

5. Schematic representation of the sequence of events occurring in the ovary during a complete follicular cycle

6. Hormone levels during a normal menstrual cycle

7. Hypophyseal-pituitary portal circulatory system