[049] SPL implantation, pregnancy and lactation(hormonal regulation)

Question 1

Answer 1

Question 2

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Question 3

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Question 4

• Are there other placental hormones ?

Answer 4

Question 5

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Question 6

Explain how blood levels of prolactin build throughout the pregnancy but lactation does not begin until AFTER delivery.?

Answer 6

• Prolactin increases steadily throughout the pregnancy. However the high levels of estrogen and progesterone during pregnancy inhibit the action of Prolactin on the mammary tissue so no milk production occurs. After birth the levels of estrogen and progesterone rapidly drop and their inhibitory action ends.

Question 7

Answer 7

Question 8

• What effect do high levels of estrogen have on the uterine muscles?

Answer 8

• The high estrogen levels overcome the inhibitory effects of progesterone on uterine smooth muscle. This is done by promoting the formation of gap junctions between the smooth muscle cells and the myometrium. It also increases the number of smooth muscle cell receptors for oxytocin that promote uterine contractions.

• While Relaxin Promotes the dilation of the cervix and increases the flexibility of the pubic symphysis.

Question 9

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Question 10

• Describe events for each of the three stages of parturition ?

Answer 10

Question 11

Answer 11

A

Question 12

Answer 12

A

Question 13

Answer 13

E

Question 14

Answer 14