1 Give a simple description of sexual reproduction.

2 Describe the function of the following parts of the female reproductive system: a fallopian tubes b cervix c vagina.

3 Describe how semen is formed.

4 Describe the two functions of the female reproductive system.

5 Describe the role of the following in regulation of the menstrual cycle: a) FSH b) LH.

6 What is menstruation? 7 What triggers menstruation?

The development, impact and management of endometriosis

Endometriosis is a condition where cells similar to those of the endometrium grow outside the uterus, typically in the ovaries or fallopian tubes.

Other parts of the abdominal cavity may be affected, such as the intestines, bladder and diaphragm.

The cause of endometriosis is not known, although there have been several theories, including:

• genetics, as the condition can run in families and is more prevalent in some ethnic groups. (Task - can you find which ethnic groups are more affected?)

• a malfunction of the immune system

• cells from the endometrium spread through the body in the bloodstream or lymphatic system.

• retrograde menstruation. Instead of flowing out of the body through the vagina during menstruation, endometrial cells may flow backwards through the fallopian tubes into the peritoneal cavity (the space surrounding the organs in the abdomen).

Symptoms

Can impact the body physically and have an impact on mental health.

A major symptom of endometriosis is pelvic pain (in the lower abdomen or back). Can range from mild to severe and is often worse during menstruation.

Period pain (pain during menstruation) can be much worse – it can be so debilitating that it prevents normal activities.

Sufferers can also experience pain in other situations - such as during or after sex - urinating - defecating.

Endometriosis can also cause nausea (feeling sick), constipation, diarrhoea or blood in the urine or faeces.

Heavy blood loss during periods.

The endometrial cells growing outside the uterus form lesions or adhesions. These bleed each menstrual period, and this can lead to inflammation and scarring.

About 40 per cent of endometriosis sufferers are infertile, possibly as a result of inflammation interfering with various aspects of conception.

With more advanced endometriosis, the lesions and adhesions can distort the anatomy of the pelvis, which can impair fertilisation.

Endometriosis is associated with an increased risk of developing depression and anxiety disorders. This is likely to be due, in part, to the severe pelvic pain associated with the disease. It is likely to be made worse by delays in diagnosis.

Diagnosis

Diagnosis of endometriosis takes on average eight years in the UK, with a third of sufferers consulting their GP six times or more before being diagnosed.

Patients are often told initially that their symptoms are trivial or normal.

A first step in testing for endometriosis is transvaginal ultrasound. This uses an ultrasound transducer inserted into the vagina to visualise the organs within the pelvic cavity.

The only way to accurately diagnose the extent and severity of endometriosis is to use laparoscopy. This is a surgical procedure that inserts a small camera inside the abdominal cavity to view the lesions or adhesions.

Treatment

There is no cure for endometriosis.

Treatment focuses on the relief of symptoms and includes the following:

• Painkillers, such as ibuprofen and paracetamol, can be used to treat pelvic pain.

• Hormone-based treatments include contraceptives such as the combined pill, hormone patch, IUS (intrauterine system – a contraceptive coil that releases progesterone over a 3–5 year period) or implant.

Hormone treatments reduce the production of hormones that regulate ovulation and menstruation. They can help control symptoms by making periods lighter and shorter, decreasing the growth of the endometrial-like tissue outside the uterus and reducing inflammation. However, these treatments are not suitable for a person trying to conceive.

• Surgery to remove the patches of endometriosis tissue (lesions or adhesions) can be performed by laparoscopy.

In more severe cases, surgery may remove part or all of the organs affected by endometriosis – for example, part of the colon or the appendix or uterus (hysterectomy).

Infertility

One of the main complications of endometriosis is difficulty in conceiving or full infertility.

Not fully understood but could be due to damage to the fallopian tubes or ovaries.

This can be treated by surgery to remove the endometriosis tissue and preserve the ovaries without damaging normal tissue, but this may not restore fertility.

In some cases, in vitro fertilisation (IVF, see section B2.29) can be an option, although patients with moderate to severe endometriosis can have a lower than usual chance of getting pregnant with IVF.

Case study Researchers at the University of Edinburgh have recently shown that cells from the pelvic wall of females with endometriosis produce higher amounts of lactate than normal cells, which might explain the symptoms of endometriosis. They have performed a clinical trial which has shown that dichloroacetate, a drug that reduces lactate production, can be used to successfully treat endometriosis. One of the patients in the trial went to hospital about 200 times before she was finally diagnosed with endometriosis. Initially her symptoms were attributed to IBS (irritable bowel syndrome) and coeliac disease. She even had her appendix removed. During the 12-week trial, her symptoms improved dramatically. Her pain decreased immediately and she was able to resume many of her normal activities that would have previously caused her considerable pain. The key advantage of dichloroacetate is that it is not a hormone-based treatment. More clinical trials are in progress.

Task - Endometriosis affects females, many of whom want to try to get pregnant. How would you evaluate treatment with dichloroacetate compared with hormonal treatments?

Laparoscopy: a form of keyhole surgery where a tube carrying a camera and surgical instruments is inserted into the abdominal cavity through an incision in the abdominal wall.

Oestrogen and testosterone - main hormones involved in the development of the female and male reproductive characteristics.

Oestrogen is often called the female sex hormone

Testosterone is often called the male sex hormone.

However, both hormones are found in males and females.

Females have much higher levels of oestrogen, while males have much higher levels of testosterone.

Puberty is initiated by secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus.

GnRH acts on the anterior pituitary and stimulates the secretion of FSH and LH.

GnRH in both females and males - responsible for stimulating ovaries and testes to begin secreting the sex hormones.

Leads to development a) female and male reproductive organs, b) secondary sex characteristics such as pubic and underarm (axillary) hair in both sexes, facial hair and increased muscle mass in males, and widening of the hips and breast development in females.

Females are born with hundreds of thousands of ova (egg cells) in their ovaries.

Secretion of FSH and LH by the anterior pituitary leads to the onset of the menstrual cycle.

In males, LH stimulates secretion of testosterone by the testes.

FSH makes cells in the testes more receptive to testosterone which leads to sperm production.