Human reproduction, growth and development Flashcards
Which health professionals take care of women during pregnancy and birth?
Midwives, and gynaecologists.
What do health visitors do?
Advise parents on the care of young children.
How many chromosomes are there in a human body cell?
46/23 pairs.
How is the sperm transferred from male to female?
During sexual intercourse, semen travels through the urethra and is deposited very close to the cervix. The sperms have to swim to the oviduct.
Where is the site of fertilisation?
Oviduct (Fallopian tube)
How many chromosomes do sex cells have?
23.
What happens to a zygote after fertilisation?
It divides by mitosis to form a ball of cells that is moved to the uterus where implantation occurs.
What does the ball of cells divide into?
The foetus, the amnion and the placenta.
What is the function of the amniotic fluid?
It acts as a shock absorber to protect the foetus.
What is the function of the placenta?
It is an exchange surface to allow materials to diffuse to and from the foetus including oxygen, nutrients, carbon dioxide.
What is the first stage of labour?
The muscular walls of the uterus contract in order to dilate the cervix.
What is the second stage of labour?
The uterus walls squeeze to force the baby through the vagina.
What is the third stage of labour?
Following the birth, the uterus contracts to push out the placenta.
Why do midwives suggest that pregnant women do not drink alcohol or take drugs?
Because they can cross the placenta, and can cause harm to the development of the foetus.
How does carbon monoxide reduce oxygen levels available to the foetus and reduce birth weight?
Carbon monoxide combines with haemoglobin, and so reduces the ability of the blood to carry oxygen to the foetus.
How are fraternal twins produced?
When 2 eggs are released from the ovary and fertilised.
How are identical twins produced?
The embryo splits into 2 groups of cells after implantation.
What are the benefits of breastfeeding?
Breast milk is the only natural food designed for your baby.
Breastfeeding protects your baby from infections and diseases.
Breastfeeding provides health benefits for mum.
It’s free.
It’s available whenever and wherever your baby needs a feed.
It’s the right temperature.
It can build a strong physical and emotional bond between mother and baby.
It can give you a great sense of achievement.
When are the main growth spurts?
From birth to age 2. During puberty, around 12 years old.
Why do the proportions of the body change?
Because in early life the limbs will lengthen at a faster rate than the head and other organs grow.
How long is the average menstrual cycle?
28 days.
What is the menstrual cycle controlled by?
Hormones.
When in the menstrual cycle does ovulation occur?
Approximately half way through/ 14 days.
What chemicals are used as a form of contraception?
Hormones.
If cycles are not 28 days long, when does ovulation occur?
14-16 days before the next menstruation.
Where are oestrogen and progesterone produced?
The ovaries.
What does FSH do?
Causes an egg to mature.
What do oestrogen and progesterone do?
Cause the lining of the womb to thicken so it is ready for implantation.
What happens to the uterus lining, if implantation does not occur?
The lining is shed.
If an egg is fertilised and implants in the uterus lining, why does oestrogen and progesterone continue to be produced?
To maintain the lining.
After 12 weeks of pregnancy what produces hormones that maintains the lining of the uterus?
The placenta.
What does LH do?
Stimulates ovulation, and causes the follicle to develop into the corpus luteum and produce progesterone.
What happens if a fertilised egg is not implanted?
The corpus luteum breaks down.
`What do the hormones produced by the placenta prevent?
Inhibits FSH production so no more eggs mature.
