Repro Physl 8

Question 1

What is the ratio of estrogen to progesterone towards the end of pregnancy?

Answer 1

There are higher levels of estrogen relative to progesterone

Question 2

What do high levels of estrogen at the end of pregnancy promote?

Answer 2

• The softening of the cervix
• Increase connexins between smooth muscle cells
• Increase expression of oxytocin receptors
• Increase prostaglandin receptors

Question 3

What are the four controllers of partiuiton?

Answer 3

• Properties of the myometrium
• Uterine prostaglandin secretion
• Oxytocin
• Progesterone inhibits uterine contraction during pregnancy

Question 4

How are the properties of the myometrium a controller of partuition?

Answer 4

Smooth muscle cells are autorhythmic in response to fetal stretch

Question 5

How is Prostaglandin production a controller of partuition?

Answer 5

Because they stimulate smooth muscle contraction

Question 6

How is Oxytocin production a controller of partuition?

Question 7

What is oxytocin released in response to?

Answer 7

Cervical stretch

Question 8

How is oxytocin a controller of parturition?

Answer 8

As the cervix stretches, oxytocin is released and causes contraction of the uterus

Question 9

What is the positive feedback of oxytocin in the uterus?

Answer 9

More uterine contraction causes increased uterine stretch which causes increased release of oxytocin which increases uterine contractions

Question 10

How is progesterone a controller of partuition?

Answer 10

It resists the actions of estrogen that cause uterine contractions during pregnancy. It also decreases myometrial sensitivity to estrogen, oxytocin and prostaglandins

Question 11

What is Lactogenesis?

Answer 11

Lactation, the production and secretion of milk by the mammary glands

Question 12

What are the sites of milk secretion?

Answer 12

Alveoli

Question 13

What are the two cell types in the breast alveoli?

Answer 13

• Epithelial cells lining the inner surface of the alveoli responsible for milk secretion
• Alveoli surrounded by contractile myoepithelial cells

Question 14

What is the major hormone responsible for milk production?

Answer 14

Prolactin

Question 15

Why is milk only produced after birth?

Answer 15

Estrogen and progesterone block the action of progesterone at the mammary glands

Question 16

What is the pathway from nipple mechanoreceptor stimulation?

Answer 16

Decrease dopamine secretion and increase PFR secretion. It will cause the anterior pituitary to increase prolactin secretion which stimulates the mammary glands to produce milk. Nipple mechanoreceptors also increase oxytocin from the posterior pituitary which acts on myoepithelial cells and induces contraction

Question 17

What is the milk ejection reflex driven by?

Answer 17

Contraction of myoepithelial caused by oxytocin stimulated by nipple mechanoreceptors

Question 18

What is Colostrum?

Answer 18

The first milk produced that is watery and protein-rich and has a lot of immune mediators

Question 19

How can the certain factors enter into the moms milk?

Answer 19

It can be synthesized by breast tissue and transported from maternal blood to milk or can come from the mother

Question 20

Why doesn’t the baby denature proteins in breastmilk?

Answer 20

Because newborn gastric acidity is low

Question 21

How do Oral contraceptives work?

Answer 21

Estrogen and progesterone inhibit pituitary gonadotropin release which prevents ovulation

Question 22

Why would someone take the progesterone only mini pill?

Answer 22

Because estrogen has strong inhibitory effects on prolactin release

Question 23

What are the other effects or oral contraceptives?

Answer 23

• Thickening of cervical mucus which hampers sperm movement

* Inhibits proliferation of the endometrium

Question 24

Which phase do oral contraceptives mimic?

Answer 24

The luteal phase

Question 25

How do emergency contraceptives work?

Answer 25

They give a high dose of estrogen or progesterone and interfere with ovulation and interfere with negative feedback and block ovulation. If ovulation already occurred and fertilization occurred progesterone impairs the movement of tubal cilia interferes with the transport of it to the uterus or it will interfere with implantation

Question 26

How does Mifepristone work?

Answer 26

It competes with progesterone to bind to progesterone receptors but doesn’t activate them which interferes with ovulation and implantation but can also abort!

Question 27

What causes menopause?

Answer 27

Ovarian failure where the ovaries become less responsive to gonadotropins

Question 28

Why are there increased levels of GnRH in menopausal women?

Answer 28

Because there is no negative feedback control of the hypothalamus by estrogen or inhibin