11.2 Fertilisation

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

11.2 Fertilisation

Planning

• Test knowledge
• Uitleg

   - fertilisation

   - implantation

   - development

   - HCG

• Homework
• End of class

Learning objectives

You will learn how a sperm cell fertilises an egg cell and what contraceptives you can use to prevent pregnancy.

15 seconden per vraag!

7 questions (30 sec per question)

FSH stimulates

1. follicle development AND estrogen production
2. corpus luteum development AND progesterone production

What is a follicle?

1. An immature eggcell
2. An immature eggcell with a layer of other cells
3. A maturing egg cell
4. Another word for a womb

What hormone does a growing follicle produce?

1. LH
2. FSH
3. Testosterone
4. Estrogen

It is possible to get pregnant during your menstruation

1. True
2. False

If you take the penis out of the vagina in time, you don't need to use a condom.

1. True
2. False

If you've never had your period, you can't get pregnant from sex.

1. True
2. False

You can get pregnant from the first time you have sex.

1. True
2. False

Becoming pregnant

3 mL sperm = 20 to 300 million sperm cells

Fertilisation =fusing of the nuclei of an egg cell and a sperm cell; takes place within the Fallopian tube

Impenetrable outer layer

From fertilization to implantation

• The fertilized egg begins to divide.

• A ball of dividing cells is formed. The ball goes to the uterus.

• After approx. 6 days, the ball of cells settles in the uterine lining (implantation).
  

Embryo = the ball of cells that has been implanted.

Development of an embryo

(Figure 1)

Approx. 5 days after fertilization a cavity arises in the ball of cells.

Inside is a cluster of cells: the blastocyst. This subsequently forms the embryo

 

Development of an embryo

(Figure 2)

The outer cells form bulges (villi).

These absorb nutrients and oxygen from the mother's blood vessels and return waste products.

Later, those villi become the placenta.

Placenta = where substances are exchanged between mother and child.

 

Development of an embryo

(Figure 3)

A connecting stalk will develop between the villi and the blastocyst. This stalk will later develop into the umbilical cord.

Umbilical cord = connects the baby to the placenta

HCG 

The villi produce the pregnancy hormone HCG. HCG has two effects:

• It prevents a new egg cell from maturing.

• It ensures that the uterine lining is not broken down

Pregnancy test shows if the pregnancy hormone HCG is present in the urine.

Contraceptives

Unsafe: coitus interruptus and calendar rhythm method

Condom	Prevents sperm cells to enter. Protects against STI's.
Pill	Contains estrogen and progesterone which prevent ovulation and maturing of egg cells.
Contraceptive patch and implant	Release hormones that prevent ovulation.
Copper or hormonal coil (IUD or IUS)	Decreases fertility of sperm cells and prevents implantation.
Sterilisation	Permanently blocking sperm ducts or fallopiian tubes (surgical procedure).

Morning-afterpil

Within 72 hours, you can get a morning-after pill at the pharmacy or contraception clinic.

The morning-after pill: contains a large dose of hormones. The hormones in the morning-after pill delay ovulation, preventing pregnancy.

Abortion

Abortion Pill

 A pill that induces labor to be used until 6th-9th week

Suction curretage = removing the embryo from the uterus with a kind of vacuum cleaner up to 13th week

Late abortion =Major procedure/surgery in which the embryo is removed

• First a consultation with a doctor is required, then a 5-day  waiting time (chance to change your mind) is required
  
• Possible until the 23rd week

What?	Make: 11.2 assignments 3-11, 16, 18
How?	In your (online) book. You do worksheet assignments in your notebook. Conferring in a whisper or listening to music.
Help?	Put your hand up. If you don't listen to music, you can also consult with your neighbour.
Time?	15 minuten
Finished?	Make a summary or mind map of sections 11.1 and 11.2
Output	When you're done, you've completed your homework! Now you know more about the fabric.

Let's discuss the lesson!

Don't pack your bags yet!

What did you learn today?

When de bell rings:

- Pull up your chairs

- Don't forget your phone