reproductive endocrinology part II

Question 1

how long is the fertilisation window after ovulation

Answer 1

24 hours

Question 2

How does implantation of fertilized cells into the uterus occur?

Answer 2

After fertilization, the zygote develops into a blastocyst, which attaches to the uterine wall (endometrium). The trophoblast cells invade the endometrium, securing the embryo and forming the basis of the placenta.

Question 3

How does the placenta develop at the onset of pregnancy?

Answer 3

The placenta forms from the trophoblast and maternal tissue. It facilitates nutrient, gas, and waste exchange between mother and fetus and produces hormones like hCG, progesterone, and estrogen to maintain pregnancy.

Question 4

what is detected in the blood or urine to confirm pregnancy

Answer 4

human chorionic gonadotropin (hCG)

Question 5

what is the role of human chorionic gonadtropin in early pregnancy

Answer 5

maintains the corpus luteum

Question 6

what can be injected to help people get pregnant

Answer 6

hCG

Question 7

what spikes at the start of pregnancy to prevent the destruction of corpus luteum

Answer 7

hCG

Question 8

role of progesterone in pregnancy

Answer 8

Maintains uterine lining and prevents uterine contractions.

Question 9

role of oestrogen in pregnancy

Answer 9

Promote uterine growth (myometrium) and blood flow.

Question 10

role of hPL (human placental lactogen) in pregnancy

Answer 10

Prepares breasts for lactation and regulates maternal metabolism.

Question 11

Which hormones are involved in maintaining gestation and how?

Answer 11

Progesterone: Prevents uterine contractions.
Relaxin: Softens the cervix and relaxes pelvic ligaments.
Estrogen: Supports uterine growth and prepares for labor.

Question 12

What are the major events during parturition?

Answer 12

Key Hormones: Oxytocin (induces contractions) and prostaglandins (soften the cervix).

Question 13

role of prostaglandins during pregnancy

Answer 13

help dilate your cervix (make it wider) and cause uterine contractions.

Question 14

How does lactation begin?

Answer 14

Prolactin, stimulated by reduced progesterone and estrogen after birth, promotes milk production. Oxytocin triggers milk ejection (let-down reflex) during suckling.

Question 15

How does the suckling response work?

Answer 15

Suckling stimulus: Increases prolactin (milk production) and oxytocin (milk ejection).
Inhibition of ovulation: Suppresses FSH and LH via prolactin, delaying the menstrual cycle.

Question 16

What happens when weaning occurs?

Answer 16

Reduced Suckling: Prolactin and oxytocin levels drop.
Milk Production Stops: Alveoli in the mammary glands regress, and lactation ceases.