Physiology of conception

Question 1

Which weeks after the last menstrual period does HCG peak?

Answer 1

week 4-20 during implantation, secreted by trophoblasts

Question 2

Which weeks after the last menstrual period are estrogen and progesterone produced?

Answer 2

Initially, estrogen & progesterone are released by the corpus luteum -> level increases significantly once the placenta is formed -> and keeps increasing till the end of pregnancy.
The placenta takes over the function of hCG approximately from the 24th week.

• Progesterone reduces uterus contractility and prepares the breast for lactation by stimulating the development of alveolar glands

Question 3

During pregnancy, the action of prolactin is inhibited by what?

Answer 3

Placental hormones

Question 4

What does oxytocin do in regards to milk production?

Answer 4

It increases the contraction of myoepithelial cells surrounding the alveoli

Question 5

What is the function of prolactin in regard to milk production?

Answer 5

Increases secretion by alveolar cells