Fertilization etc

Question 1

Pregnancy Stage 1?

Answer 1

Fertilization: methods of assisting sperm

Contractions of myometrium/oviduct sm mm move sperm,
Allurin attracts sperm to egg in ampulla,
Cervical mucous thins/↑ pH

Question 2

Sperm Capacitation is?

Answer 2

Initiated thru tract:
Cholesterol w/draw from head,
Surface proteins redistrib,
Ca2+ influx ↑ motility

Question 3

Sperm route thru follicle?

Answer 3

Corona radiata -> zone pellucida -> ovum cyto

Question 4

Acrosomal Rxn is?

Answer 4

Sperm receptors bind ZP3 in zona pellucida ->
acrosin released from sperm ->
allows entry into zona

Question 5

Zona Reaction is?

Answer 5

sperm fertilin binds ovum integrin receptor ->

Zona degrades ZP3 receptors/harden zona -> prevents polyspermy

Question 6

Pregnancy Stage 2?

Answer 6

Implantation:

Fertilized ovum -> blastocyst -> luteum

Question 7

Blastocyst made of what type cells? (2)

Answer 7

1) Trophoblasts (form w/ endometrium to make placenta)

2) Inner cell mass (become embryo)

Question 8

Blastocyst implants endomet how?

Answer 8

enzymes make hole for implant ->

nutrients released for embryo

Question 9

Progesterone role in implantation?

Answer 9

∆ uterus to secretory gland ->
glycogen/lipds

Relaxes myometrium

Days 20-24 optimal

Question 10

Pregnancy Step 3?

Answer 10

hCG secretion

Question 11

hCG is?

Released when?

Answer 11

Human Chorionic Gonadotropin:
Hormone from placenta -> maintains corpus luteum -> stim luteum secretion of prog/est until placenta takes over

Secreted days 8-11 of conception

Question 12

Fxn of placenta?

Answer 12

1) digestive, respiration, renal for fetus
2) prevents immun rejection
3) endocrine hormone secretion (hCG, est, prog)

Question 13

Estrogen in pregnancy?

Answer 13

Estriol most important
Levels ↑↑
Requires fetus and placenta for synth
Urine estrogen marker for fetal health

Question 14

Estrogen role during pregnancy?

Answer 14

↑ myometrium growth for labor
↑ breast ducts
Stim prolactin release
Softens pelvic ligaments
Inhib lactation

Question 15

Progesterone in pregnancy?

Answer 15

Levels ↑
wks 6-12 from luteum
wk 13 on from placenta
Synth requires maternal cholesterol

Question 16

Progesterone role in pregnancy?

Answer 16

∆ uterus to secretory gland 
cervical plug
inhib contractions
inhib PG synth
inhib lactose synth

Question 17

Gestation Stage 2?

Answer 17

38 wks
maternal physical ∆s support pregnancy

↑ blood vol, CO, resp, excretion, etc

Question 18

Uterine ∆ for 2rd trimester?

Answer 18

Prog ↓ -> uterus more excitable

Cervix relaxes via Relaxin from luteum/placenta

Question 19

Gestation Stage 3?

Answer 19

Parturition (labor/delivery/birth)

Question 20

Labor and estrogen?

Answer 20

↑ estrogen:

1) links cells for coordinated contractions
2) ↑ myo response to oxytocin
3) ↑ PGs for cervical ripening

Question 21

Labor and Oxytocin?

Answer 21

Stored in post pituitary,

Circulating levels don’t rise but myo oxytocin receptors ↑↑

Question 22

Labor and Corticotrophin-Releasing Hormone (CRH)?

Answer 22

Preps fetus to live:
Fetal CRH ↑ -> ↑ fetal ACTH -> ↑ fetal DHEA ->
↑ conversion into estrogen in placenta

fetal ACTH also ↑ cortisol -> matures lungs

CRH in maternal placenta is “clock”
↑ CRH -> early delivery
↓ CRH -> late delivery

Question 23

Labor and Inflammation?

Answer 23

Uterine stretch and macrophages from ↑ pulmonary surfactants activate NF-kB in uterus

NF-kB stim inflamm cytokines/PGs ->
↑ cervical softening
——–

Bacteria, allergic rxn, multiples can trigger labor

Question 24

Labor positive feedback?

Answer 24

pressure of fetus ↑ oxytocin

Question 25

Stages of labor? (3)

Answer 25

1) cervical dilation
2) delivery of baby
3) delivery of placenta

Question 26

Gestation Stage 4?

Answer 26

Lactation:
Prolactin stims alveolar
W/draw of placental steroids stim lactation

Question 27

Prolactin?

Answer 27

Lactogenesis hormone
Synth’d by pituitary
Release stim by Thyrotropin-releasing hormone
Release inhib by Dopamine

Question 28

Prolactin block ovulation how?

Answer 28

(Lasts for 7 months)
Inhib GnRH release -> inhib LH/FSH
Antagonizes action of LH/FSH on ovaries

Question 29

Milk Lactoferrin does?

Answer 29

blocks growth of harmful bacteria in milk

Question 30

Milk Bifidus Factor does?

Answer 30

promotes growth of helpful bacteria