Unit 2.3 - Biological Control Of Fertility

Question 1

What happens to woman after ovulation?

Answer 1

• Her body temperature rises by around 0.5 degrees

* Her cervical mucus becomes thin and watery

Question 2

Describe the use of ovulatory drugs In overcoming infertility

Answer 2

• Ovulation is stimulated by drugs that prevent the negative feedback effect of oestrogen on FSH secretion
• Other ovulatory drugs mimic the action of FSH and LH. These drugs can cause super ovulation that can result in multiple births or be used to collect ova for in vitro fertilisation (IVF) programmes.

Question 3

How do barrier methods of contraception prevent fertilisation?

Answer 3

They use a device to physically block the ability of sperm to reach the ova, e.g intra uterine device ( IVD)
Or sterilisation procedures

Question 4

What are some examples of chemical contraception?

Answer 4

• Progesterone
• Morning after pill
• Ora contraception pill

Question 5

What does the mini pill cause?

Answer 5

Thickening of the cervical mucus

Question 6

What does the morning after pill do? When can it be taken?

Answer 6

Prevents ovulation or implantation

Can be taken up to 72 hours or 120 hours after unprotected sex depending on which type of pill is used

Question 7

What does the oral contraceptive pill do?

Answer 7

It contains a combination of synthetic oestrogen and progesterone that mimics negative feedback preventing the release of FSH and LH from the pituitary gland.

Question 8

What type of fertility do men and woman show?

Answer 8

Woman show cyclical fertility leading to a fertile period

Men show continuous fertility

Question 9

What are examples of treatments for infertility?

Answer 9

• Artificial insemination
• Intra cytoplasmic sperm injection (ICSI)
• In vitro fertilisation (IVF)
• Ovulatory drugs

Question 10

Describe artificial insemination?

Answer 10

• It involves several samples of semen being collected over a period of time
• Artificial insemination is particularly useful where the male has a low sperm count
• If a partner is sterile a donor may be used to provide semen

Question 11

Explain the use of intra cytoplasmic sperm injection

Answer 11

If mature sperm are defective or very low in number, ICSI can be used. The head of the sperm is drawn into a needle and injected directly into the egg to achieve fertilisation

Question 12

Describe the process of IVF

Answer 12

• When ova are surgically removed from the ovaries after stimulation by hormones
• The ova are then mixed with sperm in a culture dish outside the female body
• The fertilised eggs are included until they have formed at least eight cells and are then transferred to the uterus for implantation