[Obstetrics and gynaecology] The ovaries

The ovaries are the reproductive glands (gonads) in females.

 

Physiology

Each ovary contains a supply of oocytes (egg cells) which is sufficient to last from the menarche (first menstruation) until the menopause (final menstruation) around 30 years later.

During every menstrual cycle, a single oocyte is released from one ovary travels along the fallopian
tube to reach the uterus.

Sometimes a second oocyte is released from the other ovary simultaenously and travels along that respective fallopian tube to reach the uterus. If each egg is successfully fertilised by a sperm cell, the result is dizygotic (non-identical) twins.

If one oocyte is successfully fertilised by one sperm cell, and the zygote becomes two embryos, the result is monozygotic (identical) twins.

Pathophysiology

• Polycystic ovary syndrome (PCOS) 
• Premature ovarian failure
• Ovarian cancer  
• Ovarian torsion