hormones during and after pregnancy

Question 1

what happens when implantation does occur? (woman becomes pregnant)

Answer 1

If implantation DOES occur, i.e. the woman becomes pregnant:

The placenta forms, which secretes Human Chorionic Gonadotrophin / hCG which maintains the corpus luteum during the early stages of pregnancy.

hCG therefore maintains the secretion of progesterone. Due to progesterone’s inhibitory effect on LH (which inhibits oestrogen secretion) more oestrogen is secreted. The combined effect of progesterone and oestrogen is to maintain the endometrium.

After the 8th week of pregnancy, the placenta takes over secretion of oestrogen and progesterone

Question 2

what is used as an indicator of pregnancy?

Answer 2

Human chorionic gonadotrophin is used as an indicator of pregnancy.

It is only produced by the blastocyst and placenta and therefore can only appear in the blood or urine of a woman if she is pregnant.

While the levels of progesterone and oestrogen increase greatly during pregnancy, this only occurs after week 8. They are present at all times, but at low levels.

Question 3

at the end of gestation what happens to progesterone and oestrogen levels?

Answer 3

At the end of gestation / pregnancy the levels of oestrogen and progesterone fall.

Question 4

At the end of gestation / pregnancy the levels of oestrogen and progesterone fall.
what does this cause the production of

Answer 4

This triggers the production of prolactin by the anterior pituitary gland. Prolactin prepares the mammary glands to produce milk.

It also stimulates the secretion of oxytocin from the posterior pituitary gland. This stimulates the muscles of the uterus to contract during birth to force the foetus out.

Question 5

what gland produces prolactin?

Answer 5

anterior pituitary gland

Question 6

what does prolactin do?

Answer 6

Prolactin prepares the mammary glands to produce milk.
allows lactation

Question 7

what gland secretes oxytocin?

Answer 7

posterior pituitary gland.

Question 8

what is the role of oxytocin?

Answer 8

timulates the muscles of the uterus to contract during birth to force the foetus out.

The action of oxytocin is an example of positive feedback. The contraction of the uterus stimulates the secretion of more oxytocin which then stimulates more contractions.

Question 9

is oxytocin positive or negative feedback?

Answer 9

oxytocin is an example of positive feedback. The contraction of the uterus stimulates the secretion of more oxytocin which then stimulates more contractions