Physiology and Health: The Biology of Controlling Fertility

Question 1

Infertility treatments and contraception are based on what?

Answer 1

The biology of fertility

Question 2

Men continually produce sperm in their testes showing what?

Answer 2

Continuous fertility

Question 3

Why do men show continuous fertility?

Answer 3

Due to relatively constant levels of pituitary hormones

Question 4

When are women fertile?

Answer 4

For a few days during each menstrual cycle

Question 5

Women show what leading to a fertile period?

Answer 5

Cyclical fertility

Question 6

The time with the highest likelihood of pregnancy resulting from sexual intercourse is from when to when?

Answer 6

From a few days before until one to two days after ovulation

Question 7

Time of ovulation can be based on what?

Answer 7

A slight rise in body temperature on the day of ovulation and the thinning of cervical mucus

Question 8

What are the evident changes in body temperature and cervical mucus after ovulation?

Answer 8

Body temperature rises by around 0.5 degrees Celsius and cervical mucus becomes thin and watery

Question 9

Female infertility may be due to failure to ovulate, which is usually the result of what?

Answer 9

A hormone imbalance

Question 10

Ovulatory or fertility drugs can be used to do what?

Answer 10

Stimulate ovulation

Question 11

Some ovulatory drugs work by preventing what?

Answer 11

The negative feedback effect of oestrogen on FSH secretion

Question 12

Other ovulatory drugs do what?

Answer 12

Mimic the action of FSH and LH

Question 13

These ovulatory drugs can cause super ovulation which can result in or be used for what?

Answer 13

Multiple births.

Or can be used to collect ova for in vitro fertilisation (IVF) programmes

Question 14

What is artificial insemination (AI)?

Answer 14

A treatment in which semen is inserted into the female reproductive tract without intercourse having taken place

Question 15

When is AI particularly useful?

Answer 15

When the male has a low sperm count

Question 16

During AI, several samples of semen are what over a period of time?

Answer 16

Collected and combined

Question 17

If a male partner is infertile (sterile) who can be used to provide semen for AI?

Answer 17

A donor

Question 18

What does IVF involve?

Answer 18

The surgical removal of eggs from ovaries after hormone stimulation, mixing with sperm to achieve fertilisation, incubation of zygotes and uterine implantation

Question 19

What is IVF used in conjunction with?

Answer 19

Pre-implantation genetic diagnosis (PGD) to identify single gene disorders and chromosomal abnormalities

Question 20

In IVF eggs are mixed with what in a culture dish?

Answer 20

Sperm

Question 21

The fertilised eggs are incubated until when and then what happens to them?

Answer 21

They have formed at least eight cells and are then transferred to the uterus for implantation

Question 22

What can be used if mature sperm are defective or very low in number?

Answer 22

Intracytoplasmic Sperm Injection (ICSI)

Question 23

What does ICSI involve?

Answer 23

The head of a sperm being drawn into a needle and injected directly into the egg to achieve fertilisation

Question 24

What is contraception and what type of methods are used?

Answer 24

The intentional prevention of pregnancy (contraception) by natural or artificial methods.
Physical and chemical methods.

Question 25

Physical methods of contraception have a biological basis and include what?

Answer 25

Barrier methods such as intra-uterine devices and sterilisation procedures

Question 26

What is a chemical method of contraception?

Answer 26

The oral contraceptive pill

Question 27

What does the contraceptive pill contain?

Answer 27

A combination of synthetic oestrogen and progesterone that mimics negative feedback, preventing the release of FSH and LH from the pituitary gland

Question 28

What does the progesterone-only (mini) pill cause?

Answer 28

Thickening of the cervical mucus preventing the entry of sperm and fertilisation

Question 29

What does the morning-after pill do?

Answer 29

Prevents ovulation or implantation