Becoming pregnant

• Biologie
• Middelbare school
• havo
• Leerjaar 2

Becoming pregnant

sperm vs egg

Sperm cells can survive for up to 4 days.

For fertilisation to occur, an egg cell must also be present in the fallopian tube.

An egg cell lives for approximately 12 to 24 hours after ovulation.

fertile days

Getting pregnant

The egg cell must be fertilized by the sperm cell

Nucleus of the sperm cell must fuse with the nucleus of the egg cell

Fertile moment

• The egg is released in one of the fallopian tubes (ovulation)
  
• The sperm cells end up in the back of the vagina
  
• The sperm cells swim through the uterus towards both fallopian tubes
  
• One sperm cell can fertilize the egg (in the fallopian tube)

The fertilization

A nucleus of a sperm cell fuses with the nucleus of an egg cell,

this takes place in the fallopian tube.

Implantation: after about 6 days the ball of cells attaches itself to the thick uterine lining. Then the woman is pregnant

Pregnancy

0-8 weeks: Embryo

8 weeks to birth: Fetus

Nutrition:

- Uterine lining (embryo)

- Placenta (fetus)

-> via the umbilical cord

Placenta

The placenta grows at the place where the embryo is implanted. The placenta contains capillaries (very thin blood vessels where gas exchange can take place).

Amniotic fluid and amniotic membranes protect the unborn child.

Amniotic membranes

Amniotic fluid

Prenatal testing

• 8-12 weeks: Ultrasound: Determine how long the woman has been pregnant
  
• From 10 weeks: NIPT test (non-invasive prenatal test) --> blood test (child's DNA) for DNA abnormalities.
  
• 13 weeks --> ultrasound for examination of abnormalities in the heart, brain, organs and limbs
  
• 20 weeks --> ultrasound (check) and gender can be determined

Ovulation

fertilisation

first divisions

implantation

These transport egg cells.

1. vagina
2. sperm ducts
3. ovaries
4. fallopian tubes

In this, a fertilised egg can develop into a baby.

1. vagina
2. sperm ducts
3. ovaries
4. fallopian tubes

This is where the development of egg cells takes place.

1. vagina
2. uterus
3. ovaries
4. fallopian tubes

How often does ovulation occur in a fertile woman?

1. every 12 to 24 hours
2. approximately once every two weeks
3. approximately once every four weeks

An egg cell that is not fertilised dies.
What happens to the remains of the egg cell?

1. The remains leave the body along with the lining and blood during menstruation.
2. The remains are absorbed into the blood in the uterus.
3. The remains are absorbed into the blood in the fallopian tube.

What happens on day 14 of the menstrual cycle?

1. menstruation
2. ovulation
3. implantation
4. pregnancy

Periodieke onthouding - Onbetrouwbaar- Ovulatie

What is the shedding of part of the uterine lining called?

1. fertilisation
2. implantation
3. menstruation
4. ovulation

menstruatiecyclus:
wat gebeurt er tijdens dag
1 t/m 5

1. ovulatie
2. innesteling
3. menstruatie
4. bevalling

Which of these parts leave a woman's body during menstruation?

1. the top layer of the uterine lining
2. an unfertilised egg cell
3. only blood
4. blood + unfertilised egg cell

Tijdens de menstruatiecyclus verandert de slijmlaag aan de binnenkant van de baarmoeder.

Hier zie je drie keer de doorsnede van een baarmoeder afgebeeld.

Bij welk moment van de menstruatiecyclus hoort de doorsnede?

during menstruation

short after menstruation

during ovulation

new egg cell matures

ovulation

egg cell dies

new egg cell matures

Menstruation

Uterine lining thickens

Menstruation

During pregnancy, the concentration of progesterone in a pregnant woman's body remains high. Progesterone inhibits the release of FSH and LH by the pituitary gland. no new ovaries mature, which means that no new ovulations occur.
Explain why this is important.

In addition to FSH and LH, the pituitary gland produces other hormones. One of them is the hormone oxytocin. Oxytocin causes the muscles of the uterus to contract in a pregnant woman.

At what point uring pregnancy is a lot of oxytocin produced?